Chat with Node.js and Express

Ready to implement a chat application using Twilio Programmable Chat Client, Node.js and Express?

This application allow users to exchange messages through different channels, using the Twilio Programmable Chat API. On this example, we'll show how to use this API capabilities to manage channels and their usages.

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Token Generation

In order to create a Twilio Programmable Chat client, you will need an access token. This token holds information about your Twilio Account and Programmable Chat API keys.

We generate this token by creating a new AccessToken and providing it with an IpMessagingGrant. The new AccessToken object is created using your Twilio credentials.

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const twilio = require('twilio');

const AccessToken = twilio.jwt.AccessToken;
const IpMessagingGrant = AccessToken.IpMessagingGrant;

function TokenGenerator(identity, deviceId) {
  const appName = 'TwilioChat';

  // Create a unique ID for the client on their current device
  const endpointId = appName + ':' + identity + ':' + deviceId;

  // Create a "grant" which enables a client to use IPM as a given user,
  // on a given device
  const ipmGrant = new IpMessagingGrant({
    serviceSid: process.env.TWILIO_IPM_SERVICE_SID,
    endpointId: endpointId,
  });

  // Create an access token which we will sign and return to the client,
  // containing the grant we just created
  const token = new AccessToken(
    process.env.TWILIO_ACCOUNT_SID,
    process.env.TWILIO_AUTH_TOKEN,
    process.env.TWILIO_API_SECRET
  );

  token.addGrant(ipmGrant);
  token.identity = identity;

  return token;
}

module.exports = { generate: TokenGenerator };
services/tokenService.js
Generate an Access Token

services/tokenService.js

We can generate a token, now we need a way for the chat app to get it.

Token Generation Controller

On our controller we expose the endpoint responsible for providing a valid token using the information provided as parameters:

  • device: identifies the device being used.
  • identity: identifies the user itself.

Once we have used the tokenService object to generate a token we can use the AccessToken's method as token.toJwt() to get the token as a String. Then we just return the token as a JSON encoded string.

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var express = require('express');
var router = express.Router();
var TokenService = require('../services/tokenService');

// POST /token
router.post('/', function(req, res) {
  var deviceId = req.body.device;
  var identity = req.body.identity;

  var token = TokenService.generate(identity, deviceId)

  res.json({
    identity: identity,
    token: token.toJwt(),
  });
});


module.exports = router;
routes/token.js
Token Generation Controller

routes/token.js

Now that we have a route that generates JWT tokens on demand, let's use this route to initialize our Twilio IP Messaging Client.

Initialize the Programmable Chat Client

Our client fetches a new Token by making a POST request to our endpoint when it calls the fetchAccessToken method.

With the token we can then initialize Twilio.Chat.Client in connectMessagingClient.

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var twiliochat = (function() {
  var tc = {};

  var GENERAL_CHANNEL_UNIQUE_NAME = 'general';
  var GENERAL_CHANNEL_NAME = 'General Channel';
  var MESSAGES_HISTORY_LIMIT = 50;

  var $channelList;
  var $inputText;
  var $usernameInput;
  var $statusRow;
  var $connectPanel;
  var $newChannelInputRow;
  var $newChannelInput;
  var $typingRow;
  var $typingPlaceholder;

  $(document).ready(function() {
    tc.$messageList = $('#message-list');
    $channelList = $('#channel-list');
    $inputText = $('#input-text');
    $usernameInput = $('#username-input');
    $statusRow = $('#status-row');
    $connectPanel = $('#connect-panel');
    $newChannelInputRow = $('#new-channel-input-row');
    $newChannelInput = $('#new-channel-input');
    $typingRow = $('#typing-row');
    $typingPlaceholder = $('#typing-placeholder');
    $usernameInput.focus();
    $usernameInput.on('keypress', handleUsernameInputKeypress);
    $inputText.on('keypress', handleInputTextKeypress);
    $newChannelInput.on('keypress', tc.handleNewChannelInputKeypress);
    $('#connect-image').on('click', connectClientWithUsername);
    $('#add-channel-image').on('click', showAddChannelInput);
    $('#leave-span').on('click', disconnectClient);
    $('#delete-channel-span').on('click', deleteCurrentChannel);
  });

  function handleUsernameInputKeypress(event) {
    if (event.keyCode === 13){
      connectClientWithUsername();
    }
  }

  function handleInputTextKeypress(event) {
    if (event.keyCode === 13) {
      tc.currentChannel.sendMessage($(this).val());
      event.preventDefault();
      $(this).val('');
    }
    else {
      notifyTyping();
    }
  }

  var notifyTyping = $.throttle(function() {
    tc.currentChannel.typing();
  }, 1000);

  tc.handleNewChannelInputKeypress = function(event) {
    if (event.keyCode === 13) {
      tc.messagingClient
        .createChannel({
          friendlyName: $newChannelInput.val(),
        })
        .then(hideAddChannelInput);

      $(this).val('');
      event.preventDefault();
    }
  };

  function connectClientWithUsername() {
    var usernameText = $usernameInput.val();
    $usernameInput.val('');
    if (usernameText == '') {
      alert('Username cannot be empty');
      return;
    }
    tc.username = usernameText;
    fetchAccessToken(tc.username, connectMessagingClient);
  }

  function fetchAccessToken(username, handler) {
    $.post('/token', {identity: username, device: 'browser'}, null, 'json')
      .done(function(response) {
        handler(response.token);
      })
      .fail(function(error) {
        console.log('Failed to fetch the Access Token with error: ' + error);
      });
  }

  function connectMessagingClient(token) {
    // Initialize the IP messaging client
    tc.messagingClient = new Twilio.Chat.Client(token);
    tc.messagingClient.initialize()
      .then(function() {
        updateConnectedUI();
        tc.loadChannelList(tc.joinGeneralChannel);
        tc.messagingClient.on('channelAdded', $.throttle(tc.loadChannelList));
        tc.messagingClient.on('channelRemoved', $.throttle(tc.loadChannelList));
        tc.messagingClient.on('tokenExpired', refreshToken);
      });
  }

  function refreshToken() {
    fetchAccessToken(tc.username, setNewToken);
  }

  function setNewToken(token) {
    tc.messagingClient.updateToken(tokenResponse.token);
  }

  function updateConnectedUI() {
    $('#username-span').text(tc.username);
    $statusRow.addClass('connected').removeClass('disconnected');
    tc.$messageList.addClass('connected').removeClass('disconnected');
    $connectPanel.addClass('connected').removeClass('disconnected');
    $inputText.addClass('with-shadow');
    $typingRow.addClass('connected').removeClass('disconnected');
  }

  tc.loadChannelList = function(handler) {
    if (tc.messagingClient === undefined) {
      console.log('Client is not initialized');
      return;
    }

    tc.messagingClient.getPublicChannels().then(function(channels) {
      tc.channelArray = tc.sortChannelsByName(channels.items);
      $channelList.text('');
      tc.channelArray.forEach(addChannel);
      if (typeof handler === 'function') {
        handler();
      }
    });
  };

  tc.joinGeneralChannel = function() {
    console.log('Attempting to join "general" chat channel...');
    if (!tc.generalChannel) {
      // If it doesn't exist, let's create it
      tc.messagingClient.createChannel({
        uniqueName: GENERAL_CHANNEL_UNIQUE_NAME,
        friendlyName: GENERAL_CHANNEL_NAME
      }).then(function(channel) {
        console.log('Created general channel');
        tc.generalChannel = channel;
        tc.loadChannelList(tc.joinGeneralChannel);
      });
    }
    else {
      console.log('Found general channel:');
      setupChannel(tc.generalChannel);
    }
  };

  function initChannel(channel) {
    console.log('Initialized channel ' + channel.friendlyName);
    return tc.messagingClient.getChannelBySid(channel.sid);
  }

  function joinChannel(_channel) {
    return _channel.join()
      .then(function(joinedChannel) {
        console.log('Joined channel ' + joinedChannel.friendlyName);
        updateChannelUI(_channel);
        tc.currentChannel = _channel;
        tc.loadMessages();
        return joinedChannel;
      });
  }

  function initChannelEvents() {
    console.log(tc.currentChannel.friendlyName + ' ready.');
    tc.currentChannel.on('messageAdded', tc.addMessageToList);
    tc.currentChannel.on('typingStarted', showTypingStarted);
    tc.currentChannel.on('typingEnded', hideTypingStarted);
    tc.currentChannel.on('memberJoined', notifyMemberJoined);
    tc.currentChannel.on('memberLeft', notifyMemberLeft);
    $inputText.prop('disabled', false).focus();
  }

  function setupChannel(channel) {
    return leaveCurrentChannel()
      .then(function() {
        return initChannel(channel);
      })
      .then(function(_channel) {
        return joinChannel(_channel);
      })
      .then(initChannelEvents);
  }

  tc.loadMessages = function() {
    tc.currentChannel.getMessages(MESSAGES_HISTORY_LIMIT).then(function (messages) {
      messages.items.forEach(tc.addMessageToList);
    });
  };

  function leaveCurrentChannel() {
    if (tc.currentChannel) {
      return tc.currentChannel.leave().then(function(leftChannel) {
        console.log('left ' + leftChannel.friendlyName);
        leftChannel.removeListener('messageAdded', tc.addMessageToList);
        leftChannel.removeListener('typingStarted', showTypingStarted);
        leftChannel.removeListener('typingEnded', hideTypingStarted);
        leftChannel.removeListener('memberJoined', notifyMemberJoined);
        leftChannel.removeListener('memberLeft', notifyMemberLeft);
      });
    } else {
      return Promise.resolve();
    }
  }

  tc.addMessageToList = function(message) {
    var rowDiv = $('<div>').addClass('row no-margin');
    rowDiv.loadTemplate($('#message-template'), {
      username: message.author,
      date: dateFormatter.getTodayDate(message.timestamp),
      body: message.body
    });
    if (message.author === tc.username) {
      rowDiv.addClass('own-message');
    }

    tc.$messageList.append(rowDiv);
    scrollToMessageListBottom();
  };

  function notifyMemberJoined(member) {
    notify(member.identity + ' joined the channel')
  }

  function notifyMemberLeft(member) {
    notify(member.identity + ' left the channel');
  }

  function notify(message) {
    var row = $('<div>').addClass('col-md-12');
    row.loadTemplate('#member-notification-template', {
      status: message
    });
    tc.$messageList.append(row);
    scrollToMessageListBottom();
  }

  function showTypingStarted(member) {
    $typingPlaceholder.text(member.identity + ' is typing...');
  }

  function hideTypingStarted(member) {
    $typingPlaceholder.text('');
  }

  function scrollToMessageListBottom() {
    tc.$messageList.scrollTop(tc.$messageList[0].scrollHeight);
  }

  function updateChannelUI(selectedChannel) {
    var channelElements = $('.channel-element').toArray();
    var channelElement = channelElements.filter(function(element) {
      return $(element).data().sid === selectedChannel.sid;
    });
    channelElement = $(channelElement);
    if (tc.currentChannelContainer === undefined && selectedChannel.uniqueName === GENERAL_CHANNEL_UNIQUE_NAME) {
      tc.currentChannelContainer = channelElement;
    }
    tc.currentChannelContainer.removeClass('selected-channel').addClass('unselected-channel');
    channelElement.removeClass('unselected-channel').addClass('selected-channel');
    tc.currentChannelContainer = channelElement;
  }

  function showAddChannelInput() {
    if (tc.messagingClient) {
      $newChannelInputRow.addClass('showing').removeClass('not-showing');
      $channelList.addClass('showing').removeClass('not-showing');
      $newChannelInput.focus();
    }
  }

  function hideAddChannelInput() {
    $newChannelInputRow.addClass('not-showing').removeClass('showing');
    $channelList.addClass('not-showing').removeClass('showing');
    $newChannelInput.val('');
  }

  function addChannel(channel) {
    if (channel.uniqueName === GENERAL_CHANNEL_UNIQUE_NAME) {
      tc.generalChannel = channel;
    }
    var rowDiv = $('<div>').addClass('row channel-row');
    rowDiv.loadTemplate('#channel-template', {
      channelName: channel.friendlyName
    });

    var channelP = rowDiv.children().children().first();

    rowDiv.on('click', selectChannel);
    channelP.data('sid', channel.sid);
    if (tc.currentChannel && channel.sid === tc.currentChannel.sid) {
      tc.currentChannelContainer = channelP;
      channelP.addClass('selected-channel');
    }
    else {
      channelP.addClass('unselected-channel')
    }

    $channelList.append(rowDiv);
  }

  function deleteCurrentChannel() {
    if (!tc.currentChannel) {
      return;
    }

    if (tc.currentChannel.sid === tc.generalChannel.sid) {
      alert('You cannot delete the general channel');
      return;
    }

    tc.currentChannel
      .delete()
      .then(function(channel) {
        console.log('channel: '+ channel.friendlyName + ' deleted');
        setupChannel(tc.generalChannel);
      });
  }

  function selectChannel(event) {
    var target = $(event.target);
    var channelSid = target.data().sid;
    var selectedChannel = tc.channelArray.filter(function(channel) {
      return channel.sid === channelSid;
    })[0];
    if (selectedChannel === tc.currentChannel) {
      return;
    }
    setupChannel(selectedChannel);
  };

  function disconnectClient() {
    leaveCurrentChannel();
    $channelList.text('');
    tc.$messageList.text('');
    channels = undefined;
    $statusRow.addClass('disconnected').removeClass('connected');
    tc.$messageList.addClass('disconnected').removeClass('connected');
    $connectPanel.addClass('disconnected').removeClass('connected');
    $inputText.removeClass('with-shadow');
    $typingRow.addClass('disconnected').removeClass('connected');
  }

  tc.sortChannelsByName = function(channels) {
    return channels.sort(function(a, b) {
      if (a.friendlyName === GENERAL_CHANNEL_NAME) {
        return -1;
      }
      if (b.friendlyName === GENERAL_CHANNEL_NAME) {
        return 1;
      }
      return a.friendlyName.localeCompare(b.friendlyName);
    });
  };

  return tc;
})();
public/js/twiliochat.js
Initialize the IP Messaging Client

public/js/twiliochat.js

Now that we've initialized our IP Messaging Client, lets see how we can get a list of channels.

Get the Channel List

After initializing the client we can use its getPublicChannels method to retrieve all visible channels. The method returns a promise which we use to show the list of channels retrieved on the UI.

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var twiliochat = (function() {
  var tc = {};

  var GENERAL_CHANNEL_UNIQUE_NAME = 'general';
  var GENERAL_CHANNEL_NAME = 'General Channel';
  var MESSAGES_HISTORY_LIMIT = 50;

  var $channelList;
  var $inputText;
  var $usernameInput;
  var $statusRow;
  var $connectPanel;
  var $newChannelInputRow;
  var $newChannelInput;
  var $typingRow;
  var $typingPlaceholder;

  $(document).ready(function() {
    tc.$messageList = $('#message-list');
    $channelList = $('#channel-list');
    $inputText = $('#input-text');
    $usernameInput = $('#username-input');
    $statusRow = $('#status-row');
    $connectPanel = $('#connect-panel');
    $newChannelInputRow = $('#new-channel-input-row');
    $newChannelInput = $('#new-channel-input');
    $typingRow = $('#typing-row');
    $typingPlaceholder = $('#typing-placeholder');
    $usernameInput.focus();
    $usernameInput.on('keypress', handleUsernameInputKeypress);
    $inputText.on('keypress', handleInputTextKeypress);
    $newChannelInput.on('keypress', tc.handleNewChannelInputKeypress);
    $('#connect-image').on('click', connectClientWithUsername);
    $('#add-channel-image').on('click', showAddChannelInput);
    $('#leave-span').on('click', disconnectClient);
    $('#delete-channel-span').on('click', deleteCurrentChannel);
  });

  function handleUsernameInputKeypress(event) {
    if (event.keyCode === 13){
      connectClientWithUsername();
    }
  }

  function handleInputTextKeypress(event) {
    if (event.keyCode === 13) {
      tc.currentChannel.sendMessage($(this).val());
      event.preventDefault();
      $(this).val('');
    }
    else {
      notifyTyping();
    }
  }

  var notifyTyping = $.throttle(function() {
    tc.currentChannel.typing();
  }, 1000);

  tc.handleNewChannelInputKeypress = function(event) {
    if (event.keyCode === 13) {
      tc.messagingClient
        .createChannel({
          friendlyName: $newChannelInput.val(),
        })
        .then(hideAddChannelInput);

      $(this).val('');
      event.preventDefault();
    }
  };

  function connectClientWithUsername() {
    var usernameText = $usernameInput.val();
    $usernameInput.val('');
    if (usernameText == '') {
      alert('Username cannot be empty');
      return;
    }
    tc.username = usernameText;
    fetchAccessToken(tc.username, connectMessagingClient);
  }

  function fetchAccessToken(username, handler) {
    $.post('/token', {identity: username, device: 'browser'}, null, 'json')
      .done(function(response) {
        handler(response.token);
      })
      .fail(function(error) {
        console.log('Failed to fetch the Access Token with error: ' + error);
      });
  }

  function connectMessagingClient(token) {
    // Initialize the IP messaging client
    tc.messagingClient = new Twilio.Chat.Client(token);
    tc.messagingClient.initialize()
      .then(function() {
        updateConnectedUI();
        tc.loadChannelList(tc.joinGeneralChannel);
        tc.messagingClient.on('channelAdded', $.throttle(tc.loadChannelList));
        tc.messagingClient.on('channelRemoved', $.throttle(tc.loadChannelList));
        tc.messagingClient.on('tokenExpired', refreshToken);
      });
  }

  function refreshToken() {
    fetchAccessToken(tc.username, setNewToken);
  }

  function setNewToken(token) {
    tc.messagingClient.updateToken(tokenResponse.token);
  }

  function updateConnectedUI() {
    $('#username-span').text(tc.username);
    $statusRow.addClass('connected').removeClass('disconnected');
    tc.$messageList.addClass('connected').removeClass('disconnected');
    $connectPanel.addClass('connected').removeClass('disconnected');
    $inputText.addClass('with-shadow');
    $typingRow.addClass('connected').removeClass('disconnected');
  }

  tc.loadChannelList = function(handler) {
    if (tc.messagingClient === undefined) {
      console.log('Client is not initialized');
      return;
    }

    tc.messagingClient.getPublicChannels().then(function(channels) {
      tc.channelArray = tc.sortChannelsByName(channels.items);
      $channelList.text('');
      tc.channelArray.forEach(addChannel);
      if (typeof handler === 'function') {
        handler();
      }
    });
  };

  tc.joinGeneralChannel = function() {
    console.log('Attempting to join "general" chat channel...');
    if (!tc.generalChannel) {
      // If it doesn't exist, let's create it
      tc.messagingClient.createChannel({
        uniqueName: GENERAL_CHANNEL_UNIQUE_NAME,
        friendlyName: GENERAL_CHANNEL_NAME
      }).then(function(channel) {
        console.log('Created general channel');
        tc.generalChannel = channel;
        tc.loadChannelList(tc.joinGeneralChannel);
      });
    }
    else {
      console.log('Found general channel:');
      setupChannel(tc.generalChannel);
    }
  };

  function initChannel(channel) {
    console.log('Initialized channel ' + channel.friendlyName);
    return tc.messagingClient.getChannelBySid(channel.sid);
  }

  function joinChannel(_channel) {
    return _channel.join()
      .then(function(joinedChannel) {
        console.log('Joined channel ' + joinedChannel.friendlyName);
        updateChannelUI(_channel);
        tc.currentChannel = _channel;
        tc.loadMessages();
        return joinedChannel;
      });
  }

  function initChannelEvents() {
    console.log(tc.currentChannel.friendlyName + ' ready.');
    tc.currentChannel.on('messageAdded', tc.addMessageToList);
    tc.currentChannel.on('typingStarted', showTypingStarted);
    tc.currentChannel.on('typingEnded', hideTypingStarted);
    tc.currentChannel.on('memberJoined', notifyMemberJoined);
    tc.currentChannel.on('memberLeft', notifyMemberLeft);
    $inputText.prop('disabled', false).focus();
  }

  function setupChannel(channel) {
    return leaveCurrentChannel()
      .then(function() {
        return initChannel(channel);
      })
      .then(function(_channel) {
        return joinChannel(_channel);
      })
      .then(initChannelEvents);
  }

  tc.loadMessages = function() {
    tc.currentChannel.getMessages(MESSAGES_HISTORY_LIMIT).then(function (messages) {
      messages.items.forEach(tc.addMessageToList);
    });
  };

  function leaveCurrentChannel() {
    if (tc.currentChannel) {
      return tc.currentChannel.leave().then(function(leftChannel) {
        console.log('left ' + leftChannel.friendlyName);
        leftChannel.removeListener('messageAdded', tc.addMessageToList);
        leftChannel.removeListener('typingStarted', showTypingStarted);
        leftChannel.removeListener('typingEnded', hideTypingStarted);
        leftChannel.removeListener('memberJoined', notifyMemberJoined);
        leftChannel.removeListener('memberLeft', notifyMemberLeft);
      });
    } else {
      return Promise.resolve();
    }
  }

  tc.addMessageToList = function(message) {
    var rowDiv = $('<div>').addClass('row no-margin');
    rowDiv.loadTemplate($('#message-template'), {
      username: message.author,
      date: dateFormatter.getTodayDate(message.timestamp),
      body: message.body
    });
    if (message.author === tc.username) {
      rowDiv.addClass('own-message');
    }

    tc.$messageList.append(rowDiv);
    scrollToMessageListBottom();
  };

  function notifyMemberJoined(member) {
    notify(member.identity + ' joined the channel')
  }

  function notifyMemberLeft(member) {
    notify(member.identity + ' left the channel');
  }

  function notify(message) {
    var row = $('<div>').addClass('col-md-12');
    row.loadTemplate('#member-notification-template', {
      status: message
    });
    tc.$messageList.append(row);
    scrollToMessageListBottom();
  }

  function showTypingStarted(member) {
    $typingPlaceholder.text(member.identity + ' is typing...');
  }

  function hideTypingStarted(member) {
    $typingPlaceholder.text('');
  }

  function scrollToMessageListBottom() {
    tc.$messageList.scrollTop(tc.$messageList[0].scrollHeight);
  }

  function updateChannelUI(selectedChannel) {
    var channelElements = $('.channel-element').toArray();
    var channelElement = channelElements.filter(function(element) {
      return $(element).data().sid === selectedChannel.sid;
    });
    channelElement = $(channelElement);
    if (tc.currentChannelContainer === undefined && selectedChannel.uniqueName === GENERAL_CHANNEL_UNIQUE_NAME) {
      tc.currentChannelContainer = channelElement;
    }
    tc.currentChannelContainer.removeClass('selected-channel').addClass('unselected-channel');
    channelElement.removeClass('unselected-channel').addClass('selected-channel');
    tc.currentChannelContainer = channelElement;
  }

  function showAddChannelInput() {
    if (tc.messagingClient) {
      $newChannelInputRow.addClass('showing').removeClass('not-showing');
      $channelList.addClass('showing').removeClass('not-showing');
      $newChannelInput.focus();
    }
  }

  function hideAddChannelInput() {
    $newChannelInputRow.addClass('not-showing').removeClass('showing');
    $channelList.addClass('not-showing').removeClass('showing');
    $newChannelInput.val('');
  }

  function addChannel(channel) {
    if (channel.uniqueName === GENERAL_CHANNEL_UNIQUE_NAME) {
      tc.generalChannel = channel;
    }
    var rowDiv = $('<div>').addClass('row channel-row');
    rowDiv.loadTemplate('#channel-template', {
      channelName: channel.friendlyName
    });

    var channelP = rowDiv.children().children().first();

    rowDiv.on('click', selectChannel);
    channelP.data('sid', channel.sid);
    if (tc.currentChannel && channel.sid === tc.currentChannel.sid) {
      tc.currentChannelContainer = channelP;
      channelP.addClass('selected-channel');
    }
    else {
      channelP.addClass('unselected-channel')
    }

    $channelList.append(rowDiv);
  }

  function deleteCurrentChannel() {
    if (!tc.currentChannel) {
      return;
    }

    if (tc.currentChannel.sid === tc.generalChannel.sid) {
      alert('You cannot delete the general channel');
      return;
    }

    tc.currentChannel
      .delete()
      .then(function(channel) {
        console.log('channel: '+ channel.friendlyName + ' deleted');
        setupChannel(tc.generalChannel);
      });
  }

  function selectChannel(event) {
    var target = $(event.target);
    var channelSid = target.data().sid;
    var selectedChannel = tc.channelArray.filter(function(channel) {
      return channel.sid === channelSid;
    })[0];
    if (selectedChannel === tc.currentChannel) {
      return;
    }
    setupChannel(selectedChannel);
  };

  function disconnectClient() {
    leaveCurrentChannel();
    $channelList.text('');
    tc.$messageList.text('');
    channels = undefined;
    $statusRow.addClass('disconnected').removeClass('connected');
    tc.$messageList.addClass('disconnected').removeClass('connected');
    $connectPanel.addClass('disconnected').removeClass('connected');
    $inputText.removeClass('with-shadow');
    $typingRow.addClass('disconnected').removeClass('connected');
  }

  tc.sortChannelsByName = function(channels) {
    return channels.sort(function(a, b) {
      if (a.friendlyName === GENERAL_CHANNEL_NAME) {
        return -1;
      }
      if (b.friendlyName === GENERAL_CHANNEL_NAME) {
        return 1;
      }
      return a.friendlyName.localeCompare(b.friendlyName);
    });
  };

  return tc;
})();
public/js/twiliochat.js
Get the Channel List

public/js/twiliochat.js

Next, we need a default channel.

Join the General Channel

This application will try to join a channel called "General Channel" when it starts. If the channel doesn't exist, we'll create one with that name. The scope of this example application will show you how to work only with public channels, but the Programmable Chat client allows you to create private channels and handle invitations.

Notice we set a unique name for the general channel as we don't want to create a new general channel every time we start the application.

Loading Code Samples...
Language
var twiliochat = (function() {
  var tc = {};

  var GENERAL_CHANNEL_UNIQUE_NAME = 'general';
  var GENERAL_CHANNEL_NAME = 'General Channel';
  var MESSAGES_HISTORY_LIMIT = 50;

  var $channelList;
  var $inputText;
  var $usernameInput;
  var $statusRow;
  var $connectPanel;
  var $newChannelInputRow;
  var $newChannelInput;
  var $typingRow;
  var $typingPlaceholder;

  $(document).ready(function() {
    tc.$messageList = $('#message-list');
    $channelList = $('#channel-list');
    $inputText = $('#input-text');
    $usernameInput = $('#username-input');
    $statusRow = $('#status-row');
    $connectPanel = $('#connect-panel');
    $newChannelInputRow = $('#new-channel-input-row');
    $newChannelInput = $('#new-channel-input');
    $typingRow = $('#typing-row');
    $typingPlaceholder = $('#typing-placeholder');
    $usernameInput.focus();
    $usernameInput.on('keypress', handleUsernameInputKeypress);
    $inputText.on('keypress', handleInputTextKeypress);
    $newChannelInput.on('keypress', tc.handleNewChannelInputKeypress);
    $('#connect-image').on('click', connectClientWithUsername);
    $('#add-channel-image').on('click', showAddChannelInput);
    $('#leave-span').on('click', disconnectClient);
    $('#delete-channel-span').on('click', deleteCurrentChannel);
  });

  function handleUsernameInputKeypress(event) {
    if (event.keyCode === 13){
      connectClientWithUsername();
    }
  }

  function handleInputTextKeypress(event) {
    if (event.keyCode === 13) {
      tc.currentChannel.sendMessage($(this).val());
      event.preventDefault();
      $(this).val('');
    }
    else {
      notifyTyping();
    }
  }

  var notifyTyping = $.throttle(function() {
    tc.currentChannel.typing();
  }, 1000);

  tc.handleNewChannelInputKeypress = function(event) {
    if (event.keyCode === 13) {
      tc.messagingClient
        .createChannel({
          friendlyName: $newChannelInput.val(),
        })
        .then(hideAddChannelInput);

      $(this).val('');
      event.preventDefault();
    }
  };

  function connectClientWithUsername() {
    var usernameText = $usernameInput.val();
    $usernameInput.val('');
    if (usernameText == '') {
      alert('Username cannot be empty');
      return;
    }
    tc.username = usernameText;
    fetchAccessToken(tc.username, connectMessagingClient);
  }

  function fetchAccessToken(username, handler) {
    $.post('/token', {identity: username, device: 'browser'}, null, 'json')
      .done(function(response) {
        handler(response.token);
      })
      .fail(function(error) {
        console.log('Failed to fetch the Access Token with error: ' + error);
      });
  }

  function connectMessagingClient(token) {
    // Initialize the IP messaging client
    tc.messagingClient = new Twilio.Chat.Client(token);
    tc.messagingClient.initialize()
      .then(function() {
        updateConnectedUI();
        tc.loadChannelList(tc.joinGeneralChannel);
        tc.messagingClient.on('channelAdded', $.throttle(tc.loadChannelList));
        tc.messagingClient.on('channelRemoved', $.throttle(tc.loadChannelList));
        tc.messagingClient.on('tokenExpired', refreshToken);
      });
  }

  function refreshToken() {
    fetchAccessToken(tc.username, setNewToken);
  }

  function setNewToken(token) {
    tc.messagingClient.updateToken(tokenResponse.token);
  }

  function updateConnectedUI() {
    $('#username-span').text(tc.username);
    $statusRow.addClass('connected').removeClass('disconnected');
    tc.$messageList.addClass('connected').removeClass('disconnected');
    $connectPanel.addClass('connected').removeClass('disconnected');
    $inputText.addClass('with-shadow');
    $typingRow.addClass('connected').removeClass('disconnected');
  }

  tc.loadChannelList = function(handler) {
    if (tc.messagingClient === undefined) {
      console.log('Client is not initialized');
      return;
    }

    tc.messagingClient.getPublicChannels().then(function(channels) {
      tc.channelArray = tc.sortChannelsByName(channels.items);
      $channelList.text('');
      tc.channelArray.forEach(addChannel);
      if (typeof handler === 'function') {
        handler();
      }
    });
  };

  tc.joinGeneralChannel = function() {
    console.log('Attempting to join "general" chat channel...');
    if (!tc.generalChannel) {
      // If it doesn't exist, let's create it
      tc.messagingClient.createChannel({
        uniqueName: GENERAL_CHANNEL_UNIQUE_NAME,
        friendlyName: GENERAL_CHANNEL_NAME
      }).then(function(channel) {
        console.log('Created general channel');
        tc.generalChannel = channel;
        tc.loadChannelList(tc.joinGeneralChannel);
      });
    }
    else {
      console.log('Found general channel:');
      setupChannel(tc.generalChannel);
    }
  };

  function initChannel(channel) {
    console.log('Initialized channel ' + channel.friendlyName);
    return tc.messagingClient.getChannelBySid(channel.sid);
  }

  function joinChannel(_channel) {
    return _channel.join()
      .then(function(joinedChannel) {
        console.log('Joined channel ' + joinedChannel.friendlyName);
        updateChannelUI(_channel);
        tc.currentChannel = _channel;
        tc.loadMessages();
        return joinedChannel;
      });
  }

  function initChannelEvents() {
    console.log(tc.currentChannel.friendlyName + ' ready.');
    tc.currentChannel.on('messageAdded', tc.addMessageToList);
    tc.currentChannel.on('typingStarted', showTypingStarted);
    tc.currentChannel.on('typingEnded', hideTypingStarted);
    tc.currentChannel.on('memberJoined', notifyMemberJoined);
    tc.currentChannel.on('memberLeft', notifyMemberLeft);
    $inputText.prop('disabled', false).focus();
  }

  function setupChannel(channel) {
    return leaveCurrentChannel()
      .then(function() {
        return initChannel(channel);
      })
      .then(function(_channel) {
        return joinChannel(_channel);
      })
      .then(initChannelEvents);
  }

  tc.loadMessages = function() {
    tc.currentChannel.getMessages(MESSAGES_HISTORY_LIMIT).then(function (messages) {
      messages.items.forEach(tc.addMessageToList);
    });
  };

  function leaveCurrentChannel() {
    if (tc.currentChannel) {
      return tc.currentChannel.leave().then(function(leftChannel) {
        console.log('left ' + leftChannel.friendlyName);
        leftChannel.removeListener('messageAdded', tc.addMessageToList);
        leftChannel.removeListener('typingStarted', showTypingStarted);
        leftChannel.removeListener('typingEnded', hideTypingStarted);
        leftChannel.removeListener('memberJoined', notifyMemberJoined);
        leftChannel.removeListener('memberLeft', notifyMemberLeft);
      });
    } else {
      return Promise.resolve();
    }
  }

  tc.addMessageToList = function(message) {
    var rowDiv = $('<div>').addClass('row no-margin');
    rowDiv.loadTemplate($('#message-template'), {
      username: message.author,
      date: dateFormatter.getTodayDate(message.timestamp),
      body: message.body
    });
    if (message.author === tc.username) {
      rowDiv.addClass('own-message');
    }

    tc.$messageList.append(rowDiv);
    scrollToMessageListBottom();
  };

  function notifyMemberJoined(member) {
    notify(member.identity + ' joined the channel')
  }

  function notifyMemberLeft(member) {
    notify(member.identity + ' left the channel');
  }

  function notify(message) {
    var row = $('<div>').addClass('col-md-12');
    row.loadTemplate('#member-notification-template', {
      status: message
    });
    tc.$messageList.append(row);
    scrollToMessageListBottom();
  }

  function showTypingStarted(member) {
    $typingPlaceholder.text(member.identity + ' is typing...');
  }

  function hideTypingStarted(member) {
    $typingPlaceholder.text('');
  }

  function scrollToMessageListBottom() {
    tc.$messageList.scrollTop(tc.$messageList[0].scrollHeight);
  }

  function updateChannelUI(selectedChannel) {
    var channelElements = $('.channel-element').toArray();
    var channelElement = channelElements.filter(function(element) {
      return $(element).data().sid === selectedChannel.sid;
    });
    channelElement = $(channelElement);
    if (tc.currentChannelContainer === undefined && selectedChannel.uniqueName === GENERAL_CHANNEL_UNIQUE_NAME) {
      tc.currentChannelContainer = channelElement;
    }
    tc.currentChannelContainer.removeClass('selected-channel').addClass('unselected-channel');
    channelElement.removeClass('unselected-channel').addClass('selected-channel');
    tc.currentChannelContainer = channelElement;
  }

  function showAddChannelInput() {
    if (tc.messagingClient) {
      $newChannelInputRow.addClass('showing').removeClass('not-showing');
      $channelList.addClass('showing').removeClass('not-showing');
      $newChannelInput.focus();
    }
  }

  function hideAddChannelInput() {
    $newChannelInputRow.addClass('not-showing').removeClass('showing');
    $channelList.addClass('not-showing').removeClass('showing');
    $newChannelInput.val('');
  }

  function addChannel(channel) {
    if (channel.uniqueName === GENERAL_CHANNEL_UNIQUE_NAME) {
      tc.generalChannel = channel;
    }
    var rowDiv = $('<div>').addClass('row channel-row');
    rowDiv.loadTemplate('#channel-template', {
      channelName: channel.friendlyName
    });

    var channelP = rowDiv.children().children().first();

    rowDiv.on('click', selectChannel);
    channelP.data('sid', channel.sid);
    if (tc.currentChannel && channel.sid === tc.currentChannel.sid) {
      tc.currentChannelContainer = channelP;
      channelP.addClass('selected-channel');
    }
    else {
      channelP.addClass('unselected-channel')
    }

    $channelList.append(rowDiv);
  }

  function deleteCurrentChannel() {
    if (!tc.currentChannel) {
      return;
    }

    if (tc.currentChannel.sid === tc.generalChannel.sid) {
      alert('You cannot delete the general channel');
      return;
    }

    tc.currentChannel
      .delete()
      .then(function(channel) {
        console.log('channel: '+ channel.friendlyName + ' deleted');
        setupChannel(tc.generalChannel);
      });
  }

  function selectChannel(event) {
    var target = $(event.target);
    var channelSid = target.data().sid;
    var selectedChannel = tc.channelArray.filter(function(channel) {
      return channel.sid === channelSid;
    })[0];
    if (selectedChannel === tc.currentChannel) {
      return;
    }
    setupChannel(selectedChannel);
  };

  function disconnectClient() {
    leaveCurrentChannel();
    $channelList.text('');
    tc.$messageList.text('');
    channels = undefined;
    $statusRow.addClass('disconnected').removeClass('connected');
    tc.$messageList.addClass('disconnected').removeClass('connected');
    $connectPanel.addClass('disconnected').removeClass('connected');
    $inputText.removeClass('with-shadow');
    $typingRow.addClass('disconnected').removeClass('connected');
  }

  tc.sortChannelsByName = function(channels) {
    return channels.sort(function(a, b) {
      if (a.friendlyName === GENERAL_CHANNEL_NAME) {
        return -1;
      }
      if (b.friendlyName === GENERAL_CHANNEL_NAME) {
        return 1;
      }
      return a.friendlyName.localeCompare(b.friendlyName);
    });
  };

  return tc;
})();
public/js/twiliochat.js
Join the General Channel

public/js/twiliochat.js

Now let's listen for some channel events.

Listen to Channel Events

Next we listen for channel events. In our case, we're setting listeners to the following events:

  • messageAdded: When another member sends a message to the channel you are connected to.
  • typingStarted: When another member is typing a message on the channel that you are connected to.
  • typingEnded: When another member stops typing a message on the channel that you are connected to.
  • memberJoined: When another member joins the channel that you are connected to.
  • memberLeft: When another member leaves the channel that you are connected to.

We register a different function to handle each particular event.

Loading Code Samples...
Language
var twiliochat = (function() {
  var tc = {};

  var GENERAL_CHANNEL_UNIQUE_NAME = 'general';
  var GENERAL_CHANNEL_NAME = 'General Channel';
  var MESSAGES_HISTORY_LIMIT = 50;

  var $channelList;
  var $inputText;
  var $usernameInput;
  var $statusRow;
  var $connectPanel;
  var $newChannelInputRow;
  var $newChannelInput;
  var $typingRow;
  var $typingPlaceholder;

  $(document).ready(function() {
    tc.$messageList = $('#message-list');
    $channelList = $('#channel-list');
    $inputText = $('#input-text');
    $usernameInput = $('#username-input');
    $statusRow = $('#status-row');
    $connectPanel = $('#connect-panel');
    $newChannelInputRow = $('#new-channel-input-row');
    $newChannelInput = $('#new-channel-input');
    $typingRow = $('#typing-row');
    $typingPlaceholder = $('#typing-placeholder');
    $usernameInput.focus();
    $usernameInput.on('keypress', handleUsernameInputKeypress);
    $inputText.on('keypress', handleInputTextKeypress);
    $newChannelInput.on('keypress', tc.handleNewChannelInputKeypress);
    $('#connect-image').on('click', connectClientWithUsername);
    $('#add-channel-image').on('click', showAddChannelInput);
    $('#leave-span').on('click', disconnectClient);
    $('#delete-channel-span').on('click', deleteCurrentChannel);
  });

  function handleUsernameInputKeypress(event) {
    if (event.keyCode === 13){
      connectClientWithUsername();
    }
  }

  function handleInputTextKeypress(event) {
    if (event.keyCode === 13) {
      tc.currentChannel.sendMessage($(this).val());
      event.preventDefault();
      $(this).val('');
    }
    else {
      notifyTyping();
    }
  }

  var notifyTyping = $.throttle(function() {
    tc.currentChannel.typing();
  }, 1000);

  tc.handleNewChannelInputKeypress = function(event) {
    if (event.keyCode === 13) {
      tc.messagingClient
        .createChannel({
          friendlyName: $newChannelInput.val(),
        })
        .then(hideAddChannelInput);

      $(this).val('');
      event.preventDefault();
    }
  };

  function connectClientWithUsername() {
    var usernameText = $usernameInput.val();
    $usernameInput.val('');
    if (usernameText == '') {
      alert('Username cannot be empty');
      return;
    }
    tc.username = usernameText;
    fetchAccessToken(tc.username, connectMessagingClient);
  }

  function fetchAccessToken(username, handler) {
    $.post('/token', {identity: username, device: 'browser'}, null, 'json')
      .done(function(response) {
        handler(response.token);
      })
      .fail(function(error) {
        console.log('Failed to fetch the Access Token with error: ' + error);
      });
  }

  function connectMessagingClient(token) {
    // Initialize the IP messaging client
    tc.messagingClient = new Twilio.Chat.Client(token);
    tc.messagingClient.initialize()
      .then(function() {
        updateConnectedUI();
        tc.loadChannelList(tc.joinGeneralChannel);
        tc.messagingClient.on('channelAdded', $.throttle(tc.loadChannelList));
        tc.messagingClient.on('channelRemoved', $.throttle(tc.loadChannelList));
        tc.messagingClient.on('tokenExpired', refreshToken);
      });
  }

  function refreshToken() {
    fetchAccessToken(tc.username, setNewToken);
  }

  function setNewToken(token) {
    tc.messagingClient.updateToken(tokenResponse.token);
  }

  function updateConnectedUI() {
    $('#username-span').text(tc.username);
    $statusRow.addClass('connected').removeClass('disconnected');
    tc.$messageList.addClass('connected').removeClass('disconnected');
    $connectPanel.addClass('connected').removeClass('disconnected');
    $inputText.addClass('with-shadow');
    $typingRow.addClass('connected').removeClass('disconnected');
  }

  tc.loadChannelList = function(handler) {
    if (tc.messagingClient === undefined) {
      console.log('Client is not initialized');
      return;
    }

    tc.messagingClient.getPublicChannels().then(function(channels) {
      tc.channelArray = tc.sortChannelsByName(channels.items);
      $channelList.text('');
      tc.channelArray.forEach(addChannel);
      if (typeof handler === 'function') {
        handler();
      }
    });
  };

  tc.joinGeneralChannel = function() {
    console.log('Attempting to join "general" chat channel...');
    if (!tc.generalChannel) {
      // If it doesn't exist, let's create it
      tc.messagingClient.createChannel({
        uniqueName: GENERAL_CHANNEL_UNIQUE_NAME,
        friendlyName: GENERAL_CHANNEL_NAME
      }).then(function(channel) {
        console.log('Created general channel');
        tc.generalChannel = channel;
        tc.loadChannelList(tc.joinGeneralChannel);
      });
    }
    else {
      console.log('Found general channel:');
      setupChannel(tc.generalChannel);
    }
  };

  function initChannel(channel) {
    console.log('Initialized channel ' + channel.friendlyName);
    return tc.messagingClient.getChannelBySid(channel.sid);
  }

  function joinChannel(_channel) {
    return _channel.join()
      .then(function(joinedChannel) {
        console.log('Joined channel ' + joinedChannel.friendlyName);
        updateChannelUI(_channel);
        tc.currentChannel = _channel;
        tc.loadMessages();
        return joinedChannel;
      });
  }

  function initChannelEvents() {
    console.log(tc.currentChannel.friendlyName + ' ready.');
    tc.currentChannel.on('messageAdded', tc.addMessageToList);
    tc.currentChannel.on('typingStarted', showTypingStarted);
    tc.currentChannel.on('typingEnded', hideTypingStarted);
    tc.currentChannel.on('memberJoined', notifyMemberJoined);
    tc.currentChannel.on('memberLeft', notifyMemberLeft);
    $inputText.prop('disabled', false).focus();
  }

  function setupChannel(channel) {
    return leaveCurrentChannel()
      .then(function() {
        return initChannel(channel);
      })
      .then(function(_channel) {
        return joinChannel(_channel);
      })
      .then(initChannelEvents);
  }

  tc.loadMessages = function() {
    tc.currentChannel.getMessages(MESSAGES_HISTORY_LIMIT).then(function (messages) {
      messages.items.forEach(tc.addMessageToList);
    });
  };

  function leaveCurrentChannel() {
    if (tc.currentChannel) {
      return tc.currentChannel.leave().then(function(leftChannel) {
        console.log('left ' + leftChannel.friendlyName);
        leftChannel.removeListener('messageAdded', tc.addMessageToList);
        leftChannel.removeListener('typingStarted', showTypingStarted);
        leftChannel.removeListener('typingEnded', hideTypingStarted);
        leftChannel.removeListener('memberJoined', notifyMemberJoined);
        leftChannel.removeListener('memberLeft', notifyMemberLeft);
      });
    } else {
      return Promise.resolve();
    }
  }

  tc.addMessageToList = function(message) {
    var rowDiv = $('<div>').addClass('row no-margin');
    rowDiv.loadTemplate($('#message-template'), {
      username: message.author,
      date: dateFormatter.getTodayDate(message.timestamp),
      body: message.body
    });
    if (message.author === tc.username) {
      rowDiv.addClass('own-message');
    }

    tc.$messageList.append(rowDiv);
    scrollToMessageListBottom();
  };

  function notifyMemberJoined(member) {
    notify(member.identity + ' joined the channel')
  }

  function notifyMemberLeft(member) {
    notify(member.identity + ' left the channel');
  }

  function notify(message) {
    var row = $('<div>').addClass('col-md-12');
    row.loadTemplate('#member-notification-template', {
      status: message
    });
    tc.$messageList.append(row);
    scrollToMessageListBottom();
  }

  function showTypingStarted(member) {
    $typingPlaceholder.text(member.identity + ' is typing...');
  }

  function hideTypingStarted(member) {
    $typingPlaceholder.text('');
  }

  function scrollToMessageListBottom() {
    tc.$messageList.scrollTop(tc.$messageList[0].scrollHeight);
  }

  function updateChannelUI(selectedChannel) {
    var channelElements = $('.channel-element').toArray();
    var channelElement = channelElements.filter(function(element) {
      return $(element).data().sid === selectedChannel.sid;
    });
    channelElement = $(channelElement);
    if (tc.currentChannelContainer === undefined && selectedChannel.uniqueName === GENERAL_CHANNEL_UNIQUE_NAME) {
      tc.currentChannelContainer = channelElement;
    }
    tc.currentChannelContainer.removeClass('selected-channel').addClass('unselected-channel');
    channelElement.removeClass('unselected-channel').addClass('selected-channel');
    tc.currentChannelContainer = channelElement;
  }

  function showAddChannelInput() {
    if (tc.messagingClient) {
      $newChannelInputRow.addClass('showing').removeClass('not-showing');
      $channelList.addClass('showing').removeClass('not-showing');
      $newChannelInput.focus();
    }
  }

  function hideAddChannelInput() {
    $newChannelInputRow.addClass('not-showing').removeClass('showing');
    $channelList.addClass('not-showing').removeClass('showing');
    $newChannelInput.val('');
  }

  function addChannel(channel) {
    if (channel.uniqueName === GENERAL_CHANNEL_UNIQUE_NAME) {
      tc.generalChannel = channel;
    }
    var rowDiv = $('<div>').addClass('row channel-row');
    rowDiv.loadTemplate('#channel-template', {
      channelName: channel.friendlyName
    });

    var channelP = rowDiv.children().children().first();

    rowDiv.on('click', selectChannel);
    channelP.data('sid', channel.sid);
    if (tc.currentChannel && channel.sid === tc.currentChannel.sid) {
      tc.currentChannelContainer = channelP;
      channelP.addClass('selected-channel');
    }
    else {
      channelP.addClass('unselected-channel')
    }

    $channelList.append(rowDiv);
  }

  function deleteCurrentChannel() {
    if (!tc.currentChannel) {
      return;
    }

    if (tc.currentChannel.sid === tc.generalChannel.sid) {
      alert('You cannot delete the general channel');
      return;
    }

    tc.currentChannel
      .delete()
      .then(function(channel) {
        console.log('channel: '+ channel.friendlyName + ' deleted');
        setupChannel(tc.generalChannel);
      });
  }

  function selectChannel(event) {
    var target = $(event.target);
    var channelSid = target.data().sid;
    var selectedChannel = tc.channelArray.filter(function(channel) {
      return channel.sid === channelSid;
    })[0];
    if (selectedChannel === tc.currentChannel) {
      return;
    }
    setupChannel(selectedChannel);
  };

  function disconnectClient() {
    leaveCurrentChannel();
    $channelList.text('');
    tc.$messageList.text('');
    channels = undefined;
    $statusRow.addClass('disconnected').removeClass('connected');
    tc.$messageList.addClass('disconnected').removeClass('connected');
    $connectPanel.addClass('disconnected').removeClass('connected');
    $inputText.removeClass('with-shadow');
    $typingRow.addClass('disconnected').removeClass('connected');
  }

  tc.sortChannelsByName = function(channels) {
    return channels.sort(function(a, b) {
      if (a.friendlyName === GENERAL_CHANNEL_NAME) {
        return -1;
      }
      if (b.friendlyName === GENERAL_CHANNEL_NAME) {
        return 1;
      }
      return a.friendlyName.localeCompare(b.friendlyName);
    });
  };

  return tc;
})();
public/js/twiliochat.js
Listen to Channel Events

public/js/twiliochat.js

The client emits events as well. Let's see how we can listen to those events as well.

Listen to Client Events

Just like with channels, we can register handlers for events on the Client:

  • channelAdded: When a channel becomes visible to the Client.
  • channelRemoved: When a channel is no longer visible to the Client.
  • tokenExpired: When the supplied token expires.

For a complete list of client events

Loading Code Samples...
Language
var twiliochat = (function() {
  var tc = {};

  var GENERAL_CHANNEL_UNIQUE_NAME = 'general';
  var GENERAL_CHANNEL_NAME = 'General Channel';
  var MESSAGES_HISTORY_LIMIT = 50;

  var $channelList;
  var $inputText;
  var $usernameInput;
  var $statusRow;
  var $connectPanel;
  var $newChannelInputRow;
  var $newChannelInput;
  var $typingRow;
  var $typingPlaceholder;

  $(document).ready(function() {
    tc.$messageList = $('#message-list');
    $channelList = $('#channel-list');
    $inputText = $('#input-text');
    $usernameInput = $('#username-input');
    $statusRow = $('#status-row');
    $connectPanel = $('#connect-panel');
    $newChannelInputRow = $('#new-channel-input-row');
    $newChannelInput = $('#new-channel-input');
    $typingRow = $('#typing-row');
    $typingPlaceholder = $('#typing-placeholder');
    $usernameInput.focus();
    $usernameInput.on('keypress', handleUsernameInputKeypress);
    $inputText.on('keypress', handleInputTextKeypress);
    $newChannelInput.on('keypress', tc.handleNewChannelInputKeypress);
    $('#connect-image').on('click', connectClientWithUsername);
    $('#add-channel-image').on('click', showAddChannelInput);
    $('#leave-span').on('click', disconnectClient);
    $('#delete-channel-span').on('click', deleteCurrentChannel);
  });

  function handleUsernameInputKeypress(event) {
    if (event.keyCode === 13){
      connectClientWithUsername();
    }
  }

  function handleInputTextKeypress(event) {
    if (event.keyCode === 13) {
      tc.currentChannel.sendMessage($(this).val());
      event.preventDefault();
      $(this).val('');
    }
    else {
      notifyTyping();
    }
  }

  var notifyTyping = $.throttle(function() {
    tc.currentChannel.typing();
  }, 1000);

  tc.handleNewChannelInputKeypress = function(event) {
    if (event.keyCode === 13) {
      tc.messagingClient
        .createChannel({
          friendlyName: $newChannelInput.val(),
        })
        .then(hideAddChannelInput);

      $(this).val('');
      event.preventDefault();
    }
  };

  function connectClientWithUsername() {
    var usernameText = $usernameInput.val();
    $usernameInput.val('');
    if (usernameText == '') {
      alert('Username cannot be empty');
      return;
    }
    tc.username = usernameText;
    fetchAccessToken(tc.username, connectMessagingClient);
  }

  function fetchAccessToken(username, handler) {
    $.post('/token', {identity: username, device: 'browser'}, null, 'json')
      .done(function(response) {
        handler(response.token);
      })
      .fail(function(error) {
        console.log('Failed to fetch the Access Token with error: ' + error);
      });
  }

  function connectMessagingClient(token) {
    // Initialize the IP messaging client
    tc.messagingClient = new Twilio.Chat.Client(token);
    tc.messagingClient.initialize()
      .then(function() {
        updateConnectedUI();
        tc.loadChannelList(tc.joinGeneralChannel);
        tc.messagingClient.on('channelAdded', $.throttle(tc.loadChannelList));
        tc.messagingClient.on('channelRemoved', $.throttle(tc.loadChannelList));
        tc.messagingClient.on('tokenExpired', refreshToken);
      });
  }

  function refreshToken() {
    fetchAccessToken(tc.username, setNewToken);
  }

  function setNewToken(token) {
    tc.messagingClient.updateToken(tokenResponse.token);
  }

  function updateConnectedUI() {
    $('#username-span').text(tc.username);
    $statusRow.addClass('connected').removeClass('disconnected');
    tc.$messageList.addClass('connected').removeClass('disconnected');
    $connectPanel.addClass('connected').removeClass('disconnected');
    $inputText.addClass('with-shadow');
    $typingRow.addClass('connected').removeClass('disconnected');
  }

  tc.loadChannelList = function(handler) {
    if (tc.messagingClient === undefined) {
      console.log('Client is not initialized');
      return;
    }

    tc.messagingClient.getPublicChannels().then(function(channels) {
      tc.channelArray = tc.sortChannelsByName(channels.items);
      $channelList.text('');
      tc.channelArray.forEach(addChannel);
      if (typeof handler === 'function') {
        handler();
      }
    });
  };

  tc.joinGeneralChannel = function() {
    console.log('Attempting to join "general" chat channel...');
    if (!tc.generalChannel) {
      // If it doesn't exist, let's create it
      tc.messagingClient.createChannel({
        uniqueName: GENERAL_CHANNEL_UNIQUE_NAME,
        friendlyName: GENERAL_CHANNEL_NAME
      }).then(function(channel) {
        console.log('Created general channel');
        tc.generalChannel = channel;
        tc.loadChannelList(tc.joinGeneralChannel);
      });
    }
    else {
      console.log('Found general channel:');
      setupChannel(tc.generalChannel);
    }
  };

  function initChannel(channel) {
    console.log('Initialized channel ' + channel.friendlyName);
    return tc.messagingClient.getChannelBySid(channel.sid);
  }

  function joinChannel(_channel) {
    return _channel.join()
      .then(function(joinedChannel) {
        console.log('Joined channel ' + joinedChannel.friendlyName);
        updateChannelUI(_channel);
        tc.currentChannel = _channel;
        tc.loadMessages();
        return joinedChannel;
      });
  }

  function initChannelEvents() {
    console.log(tc.currentChannel.friendlyName + ' ready.');
    tc.currentChannel.on('messageAdded', tc.addMessageToList);
    tc.currentChannel.on('typingStarted', showTypingStarted);
    tc.currentChannel.on('typingEnded', hideTypingStarted);
    tc.currentChannel.on('memberJoined', notifyMemberJoined);
    tc.currentChannel.on('memberLeft', notifyMemberLeft);
    $inputText.prop('disabled', false).focus();
  }

  function setupChannel(channel) {
    return leaveCurrentChannel()
      .then(function() {
        return initChannel(channel);
      })
      .then(function(_channel) {
        return joinChannel(_channel);
      })
      .then(initChannelEvents);
  }

  tc.loadMessages = function() {
    tc.currentChannel.getMessages(MESSAGES_HISTORY_LIMIT).then(function (messages) {
      messages.items.forEach(tc.addMessageToList);
    });
  };

  function leaveCurrentChannel() {
    if (tc.currentChannel) {
      return tc.currentChannel.leave().then(function(leftChannel) {
        console.log('left ' + leftChannel.friendlyName);
        leftChannel.removeListener('messageAdded', tc.addMessageToList);
        leftChannel.removeListener('typingStarted', showTypingStarted);
        leftChannel.removeListener('typingEnded', hideTypingStarted);
        leftChannel.removeListener('memberJoined', notifyMemberJoined);
        leftChannel.removeListener('memberLeft', notifyMemberLeft);
      });
    } else {
      return Promise.resolve();
    }
  }

  tc.addMessageToList = function(message) {
    var rowDiv = $('<div>').addClass('row no-margin');
    rowDiv.loadTemplate($('#message-template'), {
      username: message.author,
      date: dateFormatter.getTodayDate(message.timestamp),
      body: message.body
    });
    if (message.author === tc.username) {
      rowDiv.addClass('own-message');
    }

    tc.$messageList.append(rowDiv);
    scrollToMessageListBottom();
  };

  function notifyMemberJoined(member) {
    notify(member.identity + ' joined the channel')
  }

  function notifyMemberLeft(member) {
    notify(member.identity + ' left the channel');
  }

  function notify(message) {
    var row = $('<div>').addClass('col-md-12');
    row.loadTemplate('#member-notification-template', {
      status: message
    });
    tc.$messageList.append(row);
    scrollToMessageListBottom();
  }

  function showTypingStarted(member) {
    $typingPlaceholder.text(member.identity + ' is typing...');
  }

  function hideTypingStarted(member) {
    $typingPlaceholder.text('');
  }

  function scrollToMessageListBottom() {
    tc.$messageList.scrollTop(tc.$messageList[0].scrollHeight);
  }

  function updateChannelUI(selectedChannel) {
    var channelElements = $('.channel-element').toArray();
    var channelElement = channelElements.filter(function(element) {
      return $(element).data().sid === selectedChannel.sid;
    });
    channelElement = $(channelElement);
    if (tc.currentChannelContainer === undefined && selectedChannel.uniqueName === GENERAL_CHANNEL_UNIQUE_NAME) {
      tc.currentChannelContainer = channelElement;
    }
    tc.currentChannelContainer.removeClass('selected-channel').addClass('unselected-channel');
    channelElement.removeClass('unselected-channel').addClass('selected-channel');
    tc.currentChannelContainer = channelElement;
  }

  function showAddChannelInput() {
    if (tc.messagingClient) {
      $newChannelInputRow.addClass('showing').removeClass('not-showing');
      $channelList.addClass('showing').removeClass('not-showing');
      $newChannelInput.focus();
    }
  }

  function hideAddChannelInput() {
    $newChannelInputRow.addClass('not-showing').removeClass('showing');
    $channelList.addClass('not-showing').removeClass('showing');
    $newChannelInput.val('');
  }

  function addChannel(channel) {
    if (channel.uniqueName === GENERAL_CHANNEL_UNIQUE_NAME) {
      tc.generalChannel = channel;
    }
    var rowDiv = $('<div>').addClass('row channel-row');
    rowDiv.loadTemplate('#channel-template', {
      channelName: channel.friendlyName
    });

    var channelP = rowDiv.children().children().first();

    rowDiv.on('click', selectChannel);
    channelP.data('sid', channel.sid);
    if (tc.currentChannel && channel.sid === tc.currentChannel.sid) {
      tc.currentChannelContainer = channelP;
      channelP.addClass('selected-channel');
    }
    else {
      channelP.addClass('unselected-channel')
    }

    $channelList.append(rowDiv);
  }

  function deleteCurrentChannel() {
    if (!tc.currentChannel) {
      return;
    }

    if (tc.currentChannel.sid === tc.generalChannel.sid) {
      alert('You cannot delete the general channel');
      return;
    }

    tc.currentChannel
      .delete()
      .then(function(channel) {
        console.log('channel: '+ channel.friendlyName + ' deleted');
        setupChannel(tc.generalChannel);
      });
  }

  function selectChannel(event) {
    var target = $(event.target);
    var channelSid = target.data().sid;
    var selectedChannel = tc.channelArray.filter(function(channel) {
      return channel.sid === channelSid;
    })[0];
    if (selectedChannel === tc.currentChannel) {
      return;
    }
    setupChannel(selectedChannel);
  };

  function disconnectClient() {
    leaveCurrentChannel();
    $channelList.text('');
    tc.$messageList.text('');
    channels = undefined;
    $statusRow.addClass('disconnected').removeClass('connected');
    tc.$messageList.addClass('disconnected').removeClass('connected');
    $connectPanel.addClass('disconnected').removeClass('connected');
    $inputText.removeClass('with-shadow');
    $typingRow.addClass('disconnected').removeClass('connected');
  }

  tc.sortChannelsByName = function(channels) {
    return channels.sort(function(a, b) {
      if (a.friendlyName === GENERAL_CHANNEL_NAME) {
        return -1;
      }
      if (b.friendlyName === GENERAL_CHANNEL_NAME) {
        return 1;
      }
      return a.friendlyName.localeCompare(b.friendlyName);
    });
  };

  return tc;
})();
public/js/twiliochat.js
Listen to Client Events

public/js/twiliochat.js

We've actually got a real chat app going here, but let's make it more interesting with multiple channels.

Create a Channel

When a user clicks on the "+ Channel" link we'll show an input text field where it's possible to type the name of the new channel. Creating a channel is as simple as calling createChannel with an object that has the friendlyName key. You can create a channel with more options listed on the Channels section of the Programmable Chat documentation.

Loading Code Samples...
Language
var twiliochat = (function() {
  var tc = {};

  var GENERAL_CHANNEL_UNIQUE_NAME = 'general';
  var GENERAL_CHANNEL_NAME = 'General Channel';
  var MESSAGES_HISTORY_LIMIT = 50;

  var $channelList;
  var $inputText;
  var $usernameInput;
  var $statusRow;
  var $connectPanel;
  var $newChannelInputRow;
  var $newChannelInput;
  var $typingRow;
  var $typingPlaceholder;

  $(document).ready(function() {
    tc.$messageList = $('#message-list');
    $channelList = $('#channel-list');
    $inputText = $('#input-text');
    $usernameInput = $('#username-input');
    $statusRow = $('#status-row');
    $connectPanel = $('#connect-panel');
    $newChannelInputRow = $('#new-channel-input-row');
    $newChannelInput = $('#new-channel-input');
    $typingRow = $('#typing-row');
    $typingPlaceholder = $('#typing-placeholder');
    $usernameInput.focus();
    $usernameInput.on('keypress', handleUsernameInputKeypress);
    $inputText.on('keypress', handleInputTextKeypress);
    $newChannelInput.on('keypress', tc.handleNewChannelInputKeypress);
    $('#connect-image').on('click', connectClientWithUsername);
    $('#add-channel-image').on('click', showAddChannelInput);
    $('#leave-span').on('click', disconnectClient);
    $('#delete-channel-span').on('click', deleteCurrentChannel);
  });

  function handleUsernameInputKeypress(event) {
    if (event.keyCode === 13){
      connectClientWithUsername();
    }
  }

  function handleInputTextKeypress(event) {
    if (event.keyCode === 13) {
      tc.currentChannel.sendMessage($(this).val());
      event.preventDefault();
      $(this).val('');
    }
    else {
      notifyTyping();
    }
  }

  var notifyTyping = $.throttle(function() {
    tc.currentChannel.typing();
  }, 1000);

  tc.handleNewChannelInputKeypress = function(event) {
    if (event.keyCode === 13) {
      tc.messagingClient
        .createChannel({
          friendlyName: $newChannelInput.val(),
        })
        .then(hideAddChannelInput);

      $(this).val('');
      event.preventDefault();
    }
  };

  function connectClientWithUsername() {
    var usernameText = $usernameInput.val();
    $usernameInput.val('');
    if (usernameText == '') {
      alert('Username cannot be empty');
      return;
    }
    tc.username = usernameText;
    fetchAccessToken(tc.username, connectMessagingClient);
  }

  function fetchAccessToken(username, handler) {
    $.post('/token', {identity: username, device: 'browser'}, null, 'json')
      .done(function(response) {
        handler(response.token);
      })
      .fail(function(error) {
        console.log('Failed to fetch the Access Token with error: ' + error);
      });
  }

  function connectMessagingClient(token) {
    // Initialize the IP messaging client
    tc.messagingClient = new Twilio.Chat.Client(token);
    tc.messagingClient.initialize()
      .then(function() {
        updateConnectedUI();
        tc.loadChannelList(tc.joinGeneralChannel);
        tc.messagingClient.on('channelAdded', $.throttle(tc.loadChannelList));
        tc.messagingClient.on('channelRemoved', $.throttle(tc.loadChannelList));
        tc.messagingClient.on('tokenExpired', refreshToken);
      });
  }

  function refreshToken() {
    fetchAccessToken(tc.username, setNewToken);
  }

  function setNewToken(token) {
    tc.messagingClient.updateToken(tokenResponse.token);
  }

  function updateConnectedUI() {
    $('#username-span').text(tc.username);
    $statusRow.addClass('connected').removeClass('disconnected');
    tc.$messageList.addClass('connected').removeClass('disconnected');
    $connectPanel.addClass('connected').removeClass('disconnected');
    $inputText.addClass('with-shadow');
    $typingRow.addClass('connected').removeClass('disconnected');
  }

  tc.loadChannelList = function(handler) {
    if (tc.messagingClient === undefined) {
      console.log('Client is not initialized');
      return;
    }

    tc.messagingClient.getPublicChannels().then(function(channels) {
      tc.channelArray = tc.sortChannelsByName(channels.items);
      $channelList.text('');
      tc.channelArray.forEach(addChannel);
      if (typeof handler === 'function') {
        handler();
      }
    });
  };

  tc.joinGeneralChannel = function() {
    console.log('Attempting to join "general" chat channel...');
    if (!tc.generalChannel) {
      // If it doesn't exist, let's create it
      tc.messagingClient.createChannel({
        uniqueName: GENERAL_CHANNEL_UNIQUE_NAME,
        friendlyName: GENERAL_CHANNEL_NAME
      }).then(function(channel) {
        console.log('Created general channel');
        tc.generalChannel = channel;
        tc.loadChannelList(tc.joinGeneralChannel);
      });
    }
    else {
      console.log('Found general channel:');
      setupChannel(tc.generalChannel);
    }
  };

  function initChannel(channel) {
    console.log('Initialized channel ' + channel.friendlyName);
    return tc.messagingClient.getChannelBySid(channel.sid);
  }

  function joinChannel(_channel) {
    return _channel.join()
      .then(function(joinedChannel) {
        console.log('Joined channel ' + joinedChannel.friendlyName);
        updateChannelUI(_channel);
        tc.currentChannel = _channel;
        tc.loadMessages();
        return joinedChannel;
      });
  }

  function initChannelEvents() {
    console.log(tc.currentChannel.friendlyName + ' ready.');
    tc.currentChannel.on('messageAdded', tc.addMessageToList);
    tc.currentChannel.on('typingStarted', showTypingStarted);
    tc.currentChannel.on('typingEnded', hideTypingStarted);
    tc.currentChannel.on('memberJoined', notifyMemberJoined);
    tc.currentChannel.on('memberLeft', notifyMemberLeft);
    $inputText.prop('disabled', false).focus();
  }

  function setupChannel(channel) {
    return leaveCurrentChannel()
      .then(function() {
        return initChannel(channel);
      })
      .then(function(_channel) {
        return joinChannel(_channel);
      })
      .then(initChannelEvents);
  }

  tc.loadMessages = function() {
    tc.currentChannel.getMessages(MESSAGES_HISTORY_LIMIT).then(function (messages) {
      messages.items.forEach(tc.addMessageToList);
    });
  };

  function leaveCurrentChannel() {
    if (tc.currentChannel) {
      return tc.currentChannel.leave().then(function(leftChannel) {
        console.log('left ' + leftChannel.friendlyName);
        leftChannel.removeListener('messageAdded', tc.addMessageToList);
        leftChannel.removeListener('typingStarted', showTypingStarted);
        leftChannel.removeListener('typingEnded', hideTypingStarted);
        leftChannel.removeListener('memberJoined', notifyMemberJoined);
        leftChannel.removeListener('memberLeft', notifyMemberLeft);
      });
    } else {
      return Promise.resolve();
    }
  }

  tc.addMessageToList = function(message) {
    var rowDiv = $('<div>').addClass('row no-margin');
    rowDiv.loadTemplate($('#message-template'), {
      username: message.author,
      date: dateFormatter.getTodayDate(message.timestamp),
      body: message.body
    });
    if (message.author === tc.username) {
      rowDiv.addClass('own-message');
    }

    tc.$messageList.append(rowDiv);
    scrollToMessageListBottom();
  };

  function notifyMemberJoined(member) {
    notify(member.identity + ' joined the channel')
  }

  function notifyMemberLeft(member) {
    notify(member.identity + ' left the channel');
  }

  function notify(message) {
    var row = $('<div>').addClass('col-md-12');
    row.loadTemplate('#member-notification-template', {
      status: message
    });
    tc.$messageList.append(row);
    scrollToMessageListBottom();
  }

  function showTypingStarted(member) {
    $typingPlaceholder.text(member.identity + ' is typing...');
  }

  function hideTypingStarted(member) {
    $typingPlaceholder.text('');
  }

  function scrollToMessageListBottom() {
    tc.$messageList.scrollTop(tc.$messageList[0].scrollHeight);
  }

  function updateChannelUI(selectedChannel) {
    var channelElements = $('.channel-element').toArray();
    var channelElement = channelElements.filter(function(element) {
      return $(element).data().sid === selectedChannel.sid;
    });
    channelElement = $(channelElement);
    if (tc.currentChannelContainer === undefined && selectedChannel.uniqueName === GENERAL_CHANNEL_UNIQUE_NAME) {
      tc.currentChannelContainer = channelElement;
    }
    tc.currentChannelContainer.removeClass('selected-channel').addClass('unselected-channel');
    channelElement.removeClass('unselected-channel').addClass('selected-channel');
    tc.currentChannelContainer = channelElement;
  }

  function showAddChannelInput() {
    if (tc.messagingClient) {
      $newChannelInputRow.addClass('showing').removeClass('not-showing');
      $channelList.addClass('showing').removeClass('not-showing');
      $newChannelInput.focus();
    }
  }

  function hideAddChannelInput() {
    $newChannelInputRow.addClass('not-showing').removeClass('showing');
    $channelList.addClass('not-showing').removeClass('showing');
    $newChannelInput.val('');
  }

  function addChannel(channel) {
    if (channel.uniqueName === GENERAL_CHANNEL_UNIQUE_NAME) {
      tc.generalChannel = channel;
    }
    var rowDiv = $('<div>').addClass('row channel-row');
    rowDiv.loadTemplate('#channel-template', {
      channelName: channel.friendlyName
    });

    var channelP = rowDiv.children().children().first();

    rowDiv.on('click', selectChannel);
    channelP.data('sid', channel.sid);
    if (tc.currentChannel && channel.sid === tc.currentChannel.sid) {
      tc.currentChannelContainer = channelP;
      channelP.addClass('selected-channel');
    }
    else {
      channelP.addClass('unselected-channel')
    }

    $channelList.append(rowDiv);
  }

  function deleteCurrentChannel() {
    if (!tc.currentChannel) {
      return;
    }

    if (tc.currentChannel.sid === tc.generalChannel.sid) {
      alert('You cannot delete the general channel');
      return;
    }

    tc.currentChannel
      .delete()
      .then(function(channel) {
        console.log('channel: '+ channel.friendlyName + ' deleted');
        setupChannel(tc.generalChannel);
      });
  }

  function selectChannel(event) {
    var target = $(event.target);
    var channelSid = target.data().sid;
    var selectedChannel = tc.channelArray.filter(function(channel) {
      return channel.sid === channelSid;
    })[0];
    if (selectedChannel === tc.currentChannel) {
      return;
    }
    setupChannel(selectedChannel);
  };

  function disconnectClient() {
    leaveCurrentChannel();
    $channelList.text('');
    tc.$messageList.text('');
    channels = undefined;
    $statusRow.addClass('disconnected').removeClass('connected');
    tc.$messageList.addClass('disconnected').removeClass('connected');
    $connectPanel.addClass('disconnected').removeClass('connected');
    $inputText.removeClass('with-shadow');
    $typingRow.addClass('disconnected').removeClass('connected');
  }

  tc.sortChannelsByName = function(channels) {
    return channels.sort(function(a, b) {
      if (a.friendlyName === GENERAL_CHANNEL_NAME) {
        return -1;
      }
      if (b.friendlyName === GENERAL_CHANNEL_NAME) {
        return 1;
      }
      return a.friendlyName.localeCompare(b.friendlyName);
    });
  };

  return tc;
})();
public/js/twiliochat.js
Create a Channel

public/js/twiliochat.js

Next, we will see how we can switch between channels.

Join Other Channels

When you tap on the name of a channel from the sidebar, that channel is set as the selectedChannel. The selectChannel method takes care of joining to the selected channel and setting up the selectedChannel.

Loading Code Samples...
Language
var twiliochat = (function() {
  var tc = {};

  var GENERAL_CHANNEL_UNIQUE_NAME = 'general';
  var GENERAL_CHANNEL_NAME = 'General Channel';
  var MESSAGES_HISTORY_LIMIT = 50;

  var $channelList;
  var $inputText;
  var $usernameInput;
  var $statusRow;
  var $connectPanel;
  var $newChannelInputRow;
  var $newChannelInput;
  var $typingRow;
  var $typingPlaceholder;

  $(document).ready(function() {
    tc.$messageList = $('#message-list');
    $channelList = $('#channel-list');
    $inputText = $('#input-text');
    $usernameInput = $('#username-input');
    $statusRow = $('#status-row');
    $connectPanel = $('#connect-panel');
    $newChannelInputRow = $('#new-channel-input-row');
    $newChannelInput = $('#new-channel-input');
    $typingRow = $('#typing-row');
    $typingPlaceholder = $('#typing-placeholder');
    $usernameInput.focus();
    $usernameInput.on('keypress', handleUsernameInputKeypress);
    $inputText.on('keypress', handleInputTextKeypress);
    $newChannelInput.on('keypress', tc.handleNewChannelInputKeypress);
    $('#connect-image').on('click', connectClientWithUsername);
    $('#add-channel-image').on('click', showAddChannelInput);
    $('#leave-span').on('click', disconnectClient);
    $('#delete-channel-span').on('click', deleteCurrentChannel);
  });

  function handleUsernameInputKeypress(event) {
    if (event.keyCode === 13){
      connectClientWithUsername();
    }
  }

  function handleInputTextKeypress(event) {
    if (event.keyCode === 13) {
      tc.currentChannel.sendMessage($(this).val());
      event.preventDefault();
      $(this).val('');
    }
    else {
      notifyTyping();
    }
  }

  var notifyTyping = $.throttle(function() {
    tc.currentChannel.typing();
  }, 1000);

  tc.handleNewChannelInputKeypress = function(event) {
    if (event.keyCode === 13) {
      tc.messagingClient
        .createChannel({
          friendlyName: $newChannelInput.val(),
        })
        .then(hideAddChannelInput);

      $(this).val('');
      event.preventDefault();
    }
  };

  function connectClientWithUsername() {
    var usernameText = $usernameInput.val();
    $usernameInput.val('');
    if (usernameText == '') {
      alert('Username cannot be empty');
      return;
    }
    tc.username = usernameText;
    fetchAccessToken(tc.username, connectMessagingClient);
  }

  function fetchAccessToken(username, handler) {
    $.post('/token', {identity: username, device: 'browser'}, null, 'json')
      .done(function(response) {
        handler(response.token);
      })
      .fail(function(error) {
        console.log('Failed to fetch the Access Token with error: ' + error);
      });
  }

  function connectMessagingClient(token) {
    // Initialize the IP messaging client
    tc.messagingClient = new Twilio.Chat.Client(token);
    tc.messagingClient.initialize()
      .then(function() {
        updateConnectedUI();
        tc.loadChannelList(tc.joinGeneralChannel);
        tc.messagingClient.on('channelAdded', $.throttle(tc.loadChannelList));
        tc.messagingClient.on('channelRemoved', $.throttle(tc.loadChannelList));
        tc.messagingClient.on('tokenExpired', refreshToken);
      });
  }

  function refreshToken() {
    fetchAccessToken(tc.username, setNewToken);
  }

  function setNewToken(token) {
    tc.messagingClient.updateToken(tokenResponse.token);
  }

  function updateConnectedUI() {
    $('#username-span').text(tc.username);
    $statusRow.addClass('connected').removeClass('disconnected');
    tc.$messageList.addClass('connected').removeClass('disconnected');
    $connectPanel.addClass('connected').removeClass('disconnected');
    $inputText.addClass('with-shadow');
    $typingRow.addClass('connected').removeClass('disconnected');
  }

  tc.loadChannelList = function(handler) {
    if (tc.messagingClient === undefined) {
      console.log('Client is not initialized');
      return;
    }

    tc.messagingClient.getPublicChannels().then(function(channels) {
      tc.channelArray = tc.sortChannelsByName(channels.items);
      $channelList.text('');
      tc.channelArray.forEach(addChannel);
      if (typeof handler === 'function') {
        handler();
      }
    });
  };

  tc.joinGeneralChannel = function() {
    console.log('Attempting to join "general" chat channel...');
    if (!tc.generalChannel) {
      // If it doesn't exist, let's create it
      tc.messagingClient.createChannel({
        uniqueName: GENERAL_CHANNEL_UNIQUE_NAME,
        friendlyName: GENERAL_CHANNEL_NAME
      }).then(function(channel) {
        console.log('Created general channel');
        tc.generalChannel = channel;
        tc.loadChannelList(tc.joinGeneralChannel);
      });
    }
    else {
      console.log('Found general channel:');
      setupChannel(tc.generalChannel);
    }
  };

  function initChannel(channel) {
    console.log('Initialized channel ' + channel.friendlyName);
    return tc.messagingClient.getChannelBySid(channel.sid);
  }

  function joinChannel(_channel) {
    return _channel.join()
      .then(function(joinedChannel) {
        console.log('Joined channel ' + joinedChannel.friendlyName);
        updateChannelUI(_channel);
        tc.currentChannel = _channel;
        tc.loadMessages();
        return joinedChannel;
      });
  }

  function initChannelEvents() {
    console.log(tc.currentChannel.friendlyName + ' ready.');
    tc.currentChannel.on('messageAdded', tc.addMessageToList);
    tc.currentChannel.on('typingStarted', showTypingStarted);
    tc.currentChannel.on('typingEnded', hideTypingStarted);
    tc.currentChannel.on('memberJoined', notifyMemberJoined);
    tc.currentChannel.on('memberLeft', notifyMemberLeft);
    $inputText.prop('disabled', false).focus();
  }

  function setupChannel(channel) {
    return leaveCurrentChannel()
      .then(function() {
        return initChannel(channel);
      })
      .then(function(_channel) {
        return joinChannel(_channel);
      })
      .then(initChannelEvents);
  }

  tc.loadMessages = function() {
    tc.currentChannel.getMessages(MESSAGES_HISTORY_LIMIT).then(function (messages) {
      messages.items.forEach(tc.addMessageToList);
    });
  };

  function leaveCurrentChannel() {
    if (tc.currentChannel) {
      return tc.currentChannel.leave().then(function(leftChannel) {
        console.log('left ' + leftChannel.friendlyName);
        leftChannel.removeListener('messageAdded', tc.addMessageToList);
        leftChannel.removeListener('typingStarted', showTypingStarted);
        leftChannel.removeListener('typingEnded', hideTypingStarted);
        leftChannel.removeListener('memberJoined', notifyMemberJoined);
        leftChannel.removeListener('memberLeft', notifyMemberLeft);
      });
    } else {
      return Promise.resolve();
    }
  }

  tc.addMessageToList = function(message) {
    var rowDiv = $('<div>').addClass('row no-margin');
    rowDiv.loadTemplate($('#message-template'), {
      username: message.author,
      date: dateFormatter.getTodayDate(message.timestamp),
      body: message.body
    });
    if (message.author === tc.username) {
      rowDiv.addClass('own-message');
    }

    tc.$messageList.append(rowDiv);
    scrollToMessageListBottom();
  };

  function notifyMemberJoined(member) {
    notify(member.identity + ' joined the channel')
  }

  function notifyMemberLeft(member) {
    notify(member.identity + ' left the channel');
  }

  function notify(message) {
    var row = $('<div>').addClass('col-md-12');
    row.loadTemplate('#member-notification-template', {
      status: message
    });
    tc.$messageList.append(row);
    scrollToMessageListBottom();
  }

  function showTypingStarted(member) {
    $typingPlaceholder.text(member.identity + ' is typing...');
  }

  function hideTypingStarted(member) {
    $typingPlaceholder.text('');
  }

  function scrollToMessageListBottom() {
    tc.$messageList.scrollTop(tc.$messageList[0].scrollHeight);
  }

  function updateChannelUI(selectedChannel) {
    var channelElements = $('.channel-element').toArray();
    var channelElement = channelElements.filter(function(element) {
      return $(element).data().sid === selectedChannel.sid;
    });
    channelElement = $(channelElement);
    if (tc.currentChannelContainer === undefined && selectedChannel.uniqueName === GENERAL_CHANNEL_UNIQUE_NAME) {
      tc.currentChannelContainer = channelElement;
    }
    tc.currentChannelContainer.removeClass('selected-channel').addClass('unselected-channel');
    channelElement.removeClass('unselected-channel').addClass('selected-channel');
    tc.currentChannelContainer = channelElement;
  }

  function showAddChannelInput() {
    if (tc.messagingClient) {
      $newChannelInputRow.addClass('showing').removeClass('not-showing');
      $channelList.addClass('showing').removeClass('not-showing');
      $newChannelInput.focus();
    }
  }

  function hideAddChannelInput() {
    $newChannelInputRow.addClass('not-showing').removeClass('showing');
    $channelList.addClass('not-showing').removeClass('showing');
    $newChannelInput.val('');
  }

  function addChannel(channel) {
    if (channel.uniqueName === GENERAL_CHANNEL_UNIQUE_NAME) {
      tc.generalChannel = channel;
    }
    var rowDiv = $('<div>').addClass('row channel-row');
    rowDiv.loadTemplate('#channel-template', {
      channelName: channel.friendlyName
    });

    var channelP = rowDiv.children().children().first();

    rowDiv.on('click', selectChannel);
    channelP.data('sid', channel.sid);
    if (tc.currentChannel && channel.sid === tc.currentChannel.sid) {
      tc.currentChannelContainer = channelP;
      channelP.addClass('selected-channel');
    }
    else {
      channelP.addClass('unselected-channel')
    }

    $channelList.append(rowDiv);
  }

  function deleteCurrentChannel() {
    if (!tc.currentChannel) {
      return;
    }

    if (tc.currentChannel.sid === tc.generalChannel.sid) {
      alert('You cannot delete the general channel');
      return;
    }

    tc.currentChannel
      .delete()
      .then(function(channel) {
        console.log('channel: '+ channel.friendlyName + ' deleted');
        setupChannel(tc.generalChannel);
      });
  }

  function selectChannel(event) {
    var target = $(event.target);
    var channelSid = target.data().sid;
    var selectedChannel = tc.channelArray.filter(function(channel) {
      return channel.sid === channelSid;
    })[0];
    if (selectedChannel === tc.currentChannel) {
      return;
    }
    setupChannel(selectedChannel);
  };

  function disconnectClient() {
    leaveCurrentChannel();
    $channelList.text('');
    tc.$messageList.text('');
    channels = undefined;
    $statusRow.addClass('disconnected').removeClass('connected');
    tc.$messageList.addClass('disconnected').removeClass('connected');
    $connectPanel.addClass('disconnected').removeClass('connected');
    $inputText.removeClass('with-shadow');
    $typingRow.addClass('disconnected').removeClass('connected');
  }

  tc.sortChannelsByName = function(channels) {
    return channels.sort(function(a, b) {
      if (a.friendlyName === GENERAL_CHANNEL_NAME) {
        return -1;
      }
      if (b.friendlyName === GENERAL_CHANNEL_NAME) {
        return 1;
      }
      return a.friendlyName.localeCompare(b.friendlyName);
    });
  };

  return tc;
})();
public/js/twiliochat.js
Join Other Channels

public/js/twiliochat.js

At some point your users will want to delete a channel. Let's have a look at how that can be done.

Delete a Channel

Deleting a channel is easier than creating one. The application lets the user delete the channel they are currently on through the "delete current channel" link. The only thing you need to do to actually delete the channel from Twilio, is call the delete method on the channel you are trying to delete. Like other methods on the Channel object, it'll return a promise where you can set the success handler.

Loading Code Samples...
Language
var twiliochat = (function() {
  var tc = {};

  var GENERAL_CHANNEL_UNIQUE_NAME = 'general';
  var GENERAL_CHANNEL_NAME = 'General Channel';
  var MESSAGES_HISTORY_LIMIT = 50;

  var $channelList;
  var $inputText;
  var $usernameInput;
  var $statusRow;
  var $connectPanel;
  var $newChannelInputRow;
  var $newChannelInput;
  var $typingRow;
  var $typingPlaceholder;

  $(document).ready(function() {
    tc.$messageList = $('#message-list');
    $channelList = $('#channel-list');
    $inputText = $('#input-text');
    $usernameInput = $('#username-input');
    $statusRow = $('#status-row');
    $connectPanel = $('#connect-panel');
    $newChannelInputRow = $('#new-channel-input-row');
    $newChannelInput = $('#new-channel-input');
    $typingRow = $('#typing-row');
    $typingPlaceholder = $('#typing-placeholder');
    $usernameInput.focus();
    $usernameInput.on('keypress', handleUsernameInputKeypress);
    $inputText.on('keypress', handleInputTextKeypress);
    $newChannelInput.on('keypress', tc.handleNewChannelInputKeypress);
    $('#connect-image').on('click', connectClientWithUsername);
    $('#add-channel-image').on('click', showAddChannelInput);
    $('#leave-span').on('click', disconnectClient);
    $('#delete-channel-span').on('click', deleteCurrentChannel);
  });

  function handleUsernameInputKeypress(event) {
    if (event.keyCode === 13){
      connectClientWithUsername();
    }
  }

  function handleInputTextKeypress(event) {
    if (event.keyCode === 13) {
      tc.currentChannel.sendMessage($(this).val());
      event.preventDefault();
      $(this).val('');
    }
    else {
      notifyTyping();
    }
  }

  var notifyTyping = $.throttle(function() {
    tc.currentChannel.typing();
  }, 1000);

  tc.handleNewChannelInputKeypress = function(event) {
    if (event.keyCode === 13) {
      tc.messagingClient
        .createChannel({
          friendlyName: $newChannelInput.val(),
        })
        .then(hideAddChannelInput);

      $(this).val('');
      event.preventDefault();
    }
  };

  function connectClientWithUsername() {
    var usernameText = $usernameInput.val();
    $usernameInput.val('');
    if (usernameText == '') {
      alert('Username cannot be empty');
      return;
    }
    tc.username = usernameText;
    fetchAccessToken(tc.username, connectMessagingClient);
  }

  function fetchAccessToken(username, handler) {
    $.post('/token', {identity: username, device: 'browser'}, null, 'json')
      .done(function(response) {
        handler(response.token);
      })
      .fail(function(error) {
        console.log('Failed to fetch the Access Token with error: ' + error);
      });
  }

  function connectMessagingClient(token) {
    // Initialize the IP messaging client
    tc.messagingClient = new Twilio.Chat.Client(token);
    tc.messagingClient.initialize()
      .then(function() {
        updateConnectedUI();
        tc.loadChannelList(tc.joinGeneralChannel);
        tc.messagingClient.on('channelAdded', $.throttle(tc.loadChannelList));
        tc.messagingClient.on('channelRemoved', $.throttle(tc.loadChannelList));
        tc.messagingClient.on('tokenExpired', refreshToken);
      });
  }

  function refreshToken() {
    fetchAccessToken(tc.username, setNewToken);
  }

  function setNewToken(token) {
    tc.messagingClient.updateToken(tokenResponse.token);
  }

  function updateConnectedUI() {
    $('#username-span').text(tc.username);
    $statusRow.addClass('connected').removeClass('disconnected');
    tc.$messageList.addClass('connected').removeClass('disconnected');
    $connectPanel.addClass('connected').removeClass('disconnected');
    $inputText.addClass('with-shadow');
    $typingRow.addClass('connected').removeClass('disconnected');
  }

  tc.loadChannelList = function(handler) {
    if (tc.messagingClient === undefined) {
      console.log('Client is not initialized');
      return;
    }

    tc.messagingClient.getPublicChannels().then(function(channels) {
      tc.channelArray = tc.sortChannelsByName(channels.items);
      $channelList.text('');
      tc.channelArray.forEach(addChannel);
      if (typeof handler === 'function') {
        handler();
      }
    });
  };

  tc.joinGeneralChannel = function() {
    console.log('Attempting to join "general" chat channel...');
    if (!tc.generalChannel) {
      // If it doesn't exist, let's create it
      tc.messagingClient.createChannel({
        uniqueName: GENERAL_CHANNEL_UNIQUE_NAME,
        friendlyName: GENERAL_CHANNEL_NAME
      }).then(function(channel) {
        console.log('Created general channel');
        tc.generalChannel = channel;
        tc.loadChannelList(tc.joinGeneralChannel);
      });
    }
    else {
      console.log('Found general channel:');
      setupChannel(tc.generalChannel);
    }
  };

  function initChannel(channel) {
    console.log('Initialized channel ' + channel.friendlyName);
    return tc.messagingClient.getChannelBySid(channel.sid);
  }

  function joinChannel(_channel) {
    return _channel.join()
      .then(function(joinedChannel) {
        console.log('Joined channel ' + joinedChannel.friendlyName);
        updateChannelUI(_channel);
        tc.currentChannel = _channel;
        tc.loadMessages();
        return joinedChannel;
      });
  }

  function initChannelEvents() {
    console.log(tc.currentChannel.friendlyName + ' ready.');
    tc.currentChannel.on('messageAdded', tc.addMessageToList);
    tc.currentChannel.on('typingStarted', showTypingStarted);
    tc.currentChannel.on('typingEnded', hideTypingStarted);
    tc.currentChannel.on('memberJoined', notifyMemberJoined);
    tc.currentChannel.on('memberLeft', notifyMemberLeft);
    $inputText.prop('disabled', false).focus();
  }

  function setupChannel(channel) {
    return leaveCurrentChannel()
      .then(function() {
        return initChannel(channel);
      })
      .then(function(_channel) {
        return joinChannel(_channel);
      })
      .then(initChannelEvents);
  }

  tc.loadMessages = function() {
    tc.currentChannel.getMessages(MESSAGES_HISTORY_LIMIT).then(function (messages) {
      messages.items.forEach(tc.addMessageToList);
    });
  };

  function leaveCurrentChannel() {
    if (tc.currentChannel) {
      return tc.currentChannel.leave().then(function(leftChannel) {
        console.log('left ' + leftChannel.friendlyName);
        leftChannel.removeListener('messageAdded', tc.addMessageToList);
        leftChannel.removeListener('typingStarted', showTypingStarted);
        leftChannel.removeListener('typingEnded', hideTypingStarted);
        leftChannel.removeListener('memberJoined', notifyMemberJoined);
        leftChannel.removeListener('memberLeft', notifyMemberLeft);
      });
    } else {
      return Promise.resolve();
    }
  }

  tc.addMessageToList = function(message) {
    var rowDiv = $('<div>').addClass('row no-margin');
    rowDiv.loadTemplate($('#message-template'), {
      username: message.author,
      date: dateFormatter.getTodayDate(message.timestamp),
      body: message.body
    });
    if (message.author === tc.username) {
      rowDiv.addClass('own-message');
    }

    tc.$messageList.append(rowDiv);
    scrollToMessageListBottom();
  };

  function notifyMemberJoined(member) {
    notify(member.identity + ' joined the channel')
  }

  function notifyMemberLeft(member) {
    notify(member.identity + ' left the channel');
  }

  function notify(message) {
    var row = $('<div>').addClass('col-md-12');
    row.loadTemplate('#member-notification-template', {
      status: message
    });
    tc.$messageList.append(row);
    scrollToMessageListBottom();
  }

  function showTypingStarted(member) {
    $typingPlaceholder.text(member.identity + ' is typing...');
  }

  function hideTypingStarted(member) {
    $typingPlaceholder.text('');
  }

  function scrollToMessageListBottom() {
    tc.$messageList.scrollTop(tc.$messageList[0].scrollHeight);
  }

  function updateChannelUI(selectedChannel) {
    var channelElements = $('.channel-element').toArray();
    var channelElement = channelElements.filter(function(element) {
      return $(element).data().sid === selectedChannel.sid;
    });
    channelElement = $(channelElement);
    if (tc.currentChannelContainer === undefined && selectedChannel.uniqueName === GENERAL_CHANNEL_UNIQUE_NAME) {
      tc.currentChannelContainer = channelElement;
    }
    tc.currentChannelContainer.removeClass('selected-channel').addClass('unselected-channel');
    channelElement.removeClass('unselected-channel').addClass('selected-channel');
    tc.currentChannelContainer = channelElement;
  }

  function showAddChannelInput() {
    if (tc.messagingClient) {
      $newChannelInputRow.addClass('showing').removeClass('not-showing');
      $channelList.addClass('showing').removeClass('not-showing');
      $newChannelInput.focus();
    }
  }

  function hideAddChannelInput() {
    $newChannelInputRow.addClass('not-showing').removeClass('showing');
    $channelList.addClass('not-showing').removeClass('showing');
    $newChannelInput.val('');
  }

  function addChannel(channel) {
    if (channel.uniqueName === GENERAL_CHANNEL_UNIQUE_NAME) {
      tc.generalChannel = channel;
    }
    var rowDiv = $('<div>').addClass('row channel-row');
    rowDiv.loadTemplate('#channel-template', {
      channelName: channel.friendlyName
    });

    var channelP = rowDiv.children().children().first();

    rowDiv.on('click', selectChannel);
    channelP.data('sid', channel.sid);
    if (tc.currentChannel && channel.sid === tc.currentChannel.sid) {
      tc.currentChannelContainer = channelP;
      channelP.addClass('selected-channel');
    }
    else {
      channelP.addClass('unselected-channel')
    }

    $channelList.append(rowDiv);
  }

  function deleteCurrentChannel() {
    if (!tc.currentChannel) {
      return;
    }

    if (tc.currentChannel.sid === tc.generalChannel.sid) {
      alert('You cannot delete the general channel');
      return;
    }

    tc.currentChannel
      .delete()
      .then(function(channel) {
        console.log('channel: '+ channel.friendlyName + ' deleted');
        setupChannel(tc.generalChannel);
      });
  }

  function selectChannel(event) {
    var target = $(event.target);
    var channelSid = target.data().sid;
    var selectedChannel = tc.channelArray.filter(function(channel) {
      return channel.sid === channelSid;
    })[0];
    if (selectedChannel === tc.currentChannel) {
      return;
    }
    setupChannel(selectedChannel);
  };

  function disconnectClient() {
    leaveCurrentChannel();
    $channelList.text('');
    tc.$messageList.text('');
    channels = undefined;
    $statusRow.addClass('disconnected').removeClass('connected');
    tc.$messageList.addClass('disconnected').removeClass('connected');
    $connectPanel.addClass('disconnected').removeClass('connected');
    $inputText.removeClass('with-shadow');
    $typingRow.addClass('disconnected').removeClass('connected');
  }

  tc.sortChannelsByName = function(channels) {
    return channels.sort(function(a, b) {
      if (a.friendlyName === GENERAL_CHANNEL_NAME) {
        return -1;
      }
      if (b.friendlyName === GENERAL_CHANNEL_NAME) {
        return 1;
      }
      return a.friendlyName.localeCompare(b.friendlyName);
    });
  };

  return tc;
})();
public/js/twiliochat.js
Delete a Channel

public/js/twiliochat.js

That's it! We've just implemented a simple chat application for Node.js using Express.

Where to Next?

If you are a Node developer working with Twilio, you might want to check out these other tutorials:

Click-To-Call

Put a button on your web page that connects visitors to live support or sales people via telephone.

Automated Survey

Instantly collect structured data from your users with a survey conducted over a voice call or SMS text messages.

Did this help?

Thanks for checking out this tutorial! If you have any feedback to share with us, we'd love to hear it. Tweet @twilio to let us know what you think.

Jose Oliveros
David Prothero
Andrew Baker

Need some help?

We all do sometimes; code is hard. Get help now from our support team, or lean on the wisdom of the crowd browsing the Twilio tag on Stack Overflow.

1 / 1
Loading Code Samples...
const twilio = require('twilio');

const AccessToken = twilio.jwt.AccessToken;
const IpMessagingGrant = AccessToken.IpMessagingGrant;

function TokenGenerator(identity, deviceId) {
  const appName = 'TwilioChat';

  // Create a unique ID for the client on their current device
  const endpointId = appName + ':' + identity + ':' + deviceId;

  // Create a "grant" which enables a client to use IPM as a given user,
  // on a given device
  const ipmGrant = new IpMessagingGrant({
    serviceSid: process.env.TWILIO_IPM_SERVICE_SID,
    endpointId: endpointId,
  });

  // Create an access token which we will sign and return to the client,
  // containing the grant we just created
  const token = new AccessToken(
    process.env.TWILIO_ACCOUNT_SID,
    process.env.TWILIO_AUTH_TOKEN,
    process.env.TWILIO_API_SECRET
  );

  token.addGrant(ipmGrant);
  token.identity = identity;

  return token;
}

module.exports = { generate: TokenGenerator };
var express = require('express');
var router = express.Router();
var TokenService = require('../services/tokenService');

// POST /token
router.post('/', function(req, res) {
  var deviceId = req.body.device;
  var identity = req.body.identity;

  var token = TokenService.generate(identity, deviceId)

  res.json({
    identity: identity,
    token: token.toJwt(),
  });
});


module.exports = router;
var twiliochat = (function() {
  var tc = {};

  var GENERAL_CHANNEL_UNIQUE_NAME = 'general';
  var GENERAL_CHANNEL_NAME = 'General Channel';
  var MESSAGES_HISTORY_LIMIT = 50;

  var $channelList;
  var $inputText;
  var $usernameInput;
  var $statusRow;
  var $connectPanel;
  var $newChannelInputRow;
  var $newChannelInput;
  var $typingRow;
  var $typingPlaceholder;

  $(document).ready(function() {
    tc.$messageList = $('#message-list');
    $channelList = $('#channel-list');
    $inputText = $('#input-text');
    $usernameInput = $('#username-input');
    $statusRow = $('#status-row');
    $connectPanel = $('#connect-panel');
    $newChannelInputRow = $('#new-channel-input-row');
    $newChannelInput = $('#new-channel-input');
    $typingRow = $('#typing-row');
    $typingPlaceholder = $('#typing-placeholder');
    $usernameInput.focus();
    $usernameInput.on('keypress', handleUsernameInputKeypress);
    $inputText.on('keypress', handleInputTextKeypress);
    $newChannelInput.on('keypress', tc.handleNewChannelInputKeypress);
    $('#connect-image').on('click', connectClientWithUsername);
    $('#add-channel-image').on('click', showAddChannelInput);
    $('#leave-span').on('click', disconnectClient);
    $('#delete-channel-span').on('click', deleteCurrentChannel);
  });

  function handleUsernameInputKeypress(event) {
    if (event.keyCode === 13){
      connectClientWithUsername();
    }
  }

  function handleInputTextKeypress(event) {
    if (event.keyCode === 13) {
      tc.currentChannel.sendMessage($(this).val());
      event.preventDefault();
      $(this).val('');
    }
    else {
      notifyTyping();
    }
  }

  var notifyTyping = $.throttle(function() {
    tc.currentChannel.typing();
  }, 1000);

  tc.handleNewChannelInputKeypress = function(event) {
    if (event.keyCode === 13) {
      tc.messagingClient
        .createChannel({
          friendlyName: $newChannelInput.val(),
        })
        .then(hideAddChannelInput);

      $(this).val('');
      event.preventDefault();
    }
  };

  function connectClientWithUsername() {
    var usernameText = $usernameInput.val();
    $usernameInput.val('');
    if (usernameText == '') {
      alert('Username cannot be empty');
      return;
    }
    tc.username = usernameText;
    fetchAccessToken(tc.username, connectMessagingClient);
  }

  function fetchAccessToken(username, handler) {
    $.post('/token', {identity: username, device: 'browser'}, null, 'json')
      .done(function(response) {
        handler(response.token);
      })
      .fail(function(error) {
        console.log('Failed to fetch the Access Token with error: ' + error);
      });
  }

  function connectMessagingClient(token) {
    // Initialize the IP messaging client
    tc.messagingClient = new Twilio.Chat.Client(token);
    tc.messagingClient.initialize()
      .then(function() {
        updateConnectedUI();
        tc.loadChannelList(tc.joinGeneralChannel);
        tc.messagingClient.on('channelAdded', $.throttle(tc.loadChannelList));
        tc.messagingClient.on('channelRemoved', $.throttle(tc.loadChannelList));
        tc.messagingClient.on('tokenExpired', refreshToken);
      });
  }

  function refreshToken() {
    fetchAccessToken(tc.username, setNewToken);
  }

  function setNewToken(token) {
    tc.messagingClient.updateToken(tokenResponse.token);
  }

  function updateConnectedUI() {
    $('#username-span').text(tc.username);
    $statusRow.addClass('connected').removeClass('disconnected');
    tc.$messageList.addClass('connected').removeClass('disconnected');
    $connectPanel.addClass('connected').removeClass('disconnected');
    $inputText.addClass('with-shadow');
    $typingRow.addClass('connected').removeClass('disconnected');
  }

  tc.loadChannelList = function(handler) {
    if (tc.messagingClient === undefined) {
      console.log('Client is not initialized');
      return;
    }

    tc.messagingClient.getPublicChannels().then(function(channels) {
      tc.channelArray = tc.sortChannelsByName(channels.items);
      $channelList.text('');
      tc.channelArray.forEach(addChannel);
      if (typeof handler === 'function') {
        handler();
      }
    });
  };

  tc.joinGeneralChannel = function() {
    console.log('Attempting to join "general" chat channel...');
    if (!tc.generalChannel) {
      // If it doesn't exist, let's create it
      tc.messagingClient.createChannel({
        uniqueName: GENERAL_CHANNEL_UNIQUE_NAME,
        friendlyName: GENERAL_CHANNEL_NAME
      }).then(function(channel) {
        console.log('Created general channel');
        tc.generalChannel = channel;
        tc.loadChannelList(tc.joinGeneralChannel);
      });
    }
    else {
      console.log('Found general channel:');
      setupChannel(tc.generalChannel);
    }
  };

  function initChannel(channel) {
    console.log('Initialized channel ' + channel.friendlyName);
    return tc.messagingClient.getChannelBySid(channel.sid);
  }

  function joinChannel(_channel) {
    return _channel.join()
      .then(function(joinedChannel) {
        console.log('Joined channel ' + joinedChannel.friendlyName);
        updateChannelUI(_channel);
        tc.currentChannel = _channel;
        tc.loadMessages();
        return joinedChannel;
      });
  }

  function initChannelEvents() {
    console.log(tc.currentChannel.friendlyName + ' ready.');
    tc.currentChannel.on('messageAdded', tc.addMessageToList);
    tc.currentChannel.on('typingStarted', showTypingStarted);
    tc.currentChannel.on('typingEnded', hideTypingStarted);
    tc.currentChannel.on('memberJoined', notifyMemberJoined);
    tc.currentChannel.on('memberLeft', notifyMemberLeft);
    $inputText.prop('disabled', false).focus();
  }

  function setupChannel(channel) {
    return leaveCurrentChannel()
      .then(function() {
        return initChannel(channel);
      })
      .then(function(_channel) {
        return joinChannel(_channel);
      })
      .then(initChannelEvents);
  }

  tc.loadMessages = function() {
    tc.currentChannel.getMessages(MESSAGES_HISTORY_LIMIT).then(function (messages) {
      messages.items.forEach(tc.addMessageToList);
    });
  };

  function leaveCurrentChannel() {
    if (tc.currentChannel) {
      return tc.currentChannel.leave().then(function(leftChannel) {
        console.log('left ' + leftChannel.friendlyName);
        leftChannel.removeListener('messageAdded', tc.addMessageToList);
        leftChannel.removeListener('typingStarted', showTypingStarted);
        leftChannel.removeListener('typingEnded', hideTypingStarted);
        leftChannel.removeListener('memberJoined', notifyMemberJoined);
        leftChannel.removeListener('memberLeft', notifyMemberLeft);
      });
    } else {
      return Promise.resolve();
    }
  }

  tc.addMessageToList = function(message) {
    var rowDiv = $('<div>').addClass('row no-margin');
    rowDiv.loadTemplate($('#message-template'), {
      username: message.author,
      date: dateFormatter.getTodayDate(message.timestamp),
      body: message.body
    });
    if (message.author === tc.username) {
      rowDiv.addClass('own-message');
    }

    tc.$messageList.append(rowDiv);
    scrollToMessageListBottom();
  };

  function notifyMemberJoined(member) {
    notify(member.identity + ' joined the channel')
  }

  function notifyMemberLeft(member) {
    notify(member.identity + ' left the channel');
  }

  function notify(message) {
    var row = $('<div>').addClass('col-md-12');
    row.loadTemplate('#member-notification-template', {
      status: message
    });
    tc.$messageList.append(row);
    scrollToMessageListBottom();
  }

  function showTypingStarted(member) {
    $typingPlaceholder.text(member.identity + ' is typing...');
  }

  function hideTypingStarted(member) {
    $typingPlaceholder.text('');
  }

  function scrollToMessageListBottom() {
    tc.$messageList.scrollTop(tc.$messageList[0].scrollHeight);
  }

  function updateChannelUI(selectedChannel) {
    var channelElements = $('.channel-element').toArray();
    var channelElement = channelElements.filter(function(element) {
      return $(element).data().sid === selectedChannel.sid;
    });
    channelElement = $(channelElement);
    if (tc.currentChannelContainer === undefined && selectedChannel.uniqueName === GENERAL_CHANNEL_UNIQUE_NAME) {
      tc.currentChannelContainer = channelElement;
    }
    tc.currentChannelContainer.removeClass('selected-channel').addClass('unselected-channel');
    channelElement.removeClass('unselected-channel').addClass('selected-channel');
    tc.currentChannelContainer = channelElement;
  }

  function showAddChannelInput() {
    if (tc.messagingClient) {
      $newChannelInputRow.addClass('showing').removeClass('not-showing');
      $channelList.addClass('showing').removeClass('not-showing');
      $newChannelInput.focus();
    }
  }

  function hideAddChannelInput() {
    $newChannelInputRow.addClass('not-showing').removeClass('showing');
    $channelList.addClass('not-showing').removeClass('showing');
    $newChannelInput.val('');
  }

  function addChannel(channel) {
    if (channel.uniqueName === GENERAL_CHANNEL_UNIQUE_NAME) {
      tc.generalChannel = channel;
    }
    var rowDiv = $('<div>').addClass('row channel-row');
    rowDiv.loadTemplate('#channel-template', {
      channelName: channel.friendlyName
    });

    var channelP = rowDiv.children().children().first();

    rowDiv.on('click', selectChannel);
    channelP.data('sid', channel.sid);
    if (tc.currentChannel && channel.sid === tc.currentChannel.sid) {
      tc.currentChannelContainer = channelP;
      channelP.addClass('selected-channel');
    }
    else {
      channelP.addClass('unselected-channel')
    }

    $channelList.append(rowDiv);
  }

  function deleteCurrentChannel() {
    if (!tc.currentChannel) {
      return;
    }

    if (tc.currentChannel.sid === tc.generalChannel.sid) {
      alert('You cannot delete the general channel');
      return;
    }

    tc.currentChannel
      .delete()
      .then(function(channel) {
        console.log('channel: '+ channel.friendlyName + ' deleted');
        setupChannel(tc.generalChannel);
      });
  }

  function selectChannel(event) {
    var target = $(event.target);
    var channelSid = target.data().sid;
    var selectedChannel = tc.channelArray.filter(function(channel) {
      return channel.sid === channelSid;
    })[0];
    if (selectedChannel === tc.currentChannel) {
      return;
    }
    setupChannel(selectedChannel);
  };

  function disconnectClient() {
    leaveCurrentChannel();
    $channelList.text('');
    tc.$messageList.text('');
    channels = undefined;
    $statusRow.addClass('disconnected').removeClass('connected');
    tc.$messageList.addClass('disconnected').removeClass('connected');
    $connectPanel.addClass('disconnected').removeClass('connected');
    $inputText.removeClass('with-shadow');
    $typingRow.addClass('disconnected').removeClass('connected');
  }

  tc.sortChannelsByName = function(channels) {
    return channels.sort(function(a, b) {
      if (a.friendlyName === GENERAL_CHANNEL_NAME) {
        return -1;
      }
      if (b.friendlyName === GENERAL_CHANNEL_NAME) {
        return 1;
      }
      return a.friendlyName.localeCompare(b.friendlyName);
    });
  };

  return tc;
})();
var twiliochat = (function() {
  var tc = {};

  var GENERAL_CHANNEL_UNIQUE_NAME = 'general';
  var GENERAL_CHANNEL_NAME = 'General Channel';
  var MESSAGES_HISTORY_LIMIT = 50;

  var $channelList;
  var $inputText;
  var $usernameInput;
  var $statusRow;
  var $connectPanel;
  var $newChannelInputRow;
  var $newChannelInput;
  var $typingRow;
  var $typingPlaceholder;

  $(document).ready(function() {
    tc.$messageList = $('#message-list');
    $channelList = $('#channel-list');
    $inputText = $('#input-text');
    $usernameInput = $('#username-input');
    $statusRow = $('#status-row');
    $connectPanel = $('#connect-panel');
    $newChannelInputRow = $('#new-channel-input-row');
    $newChannelInput = $('#new-channel-input');
    $typingRow = $('#typing-row');
    $typingPlaceholder = $('#typing-placeholder');
    $usernameInput.focus();
    $usernameInput.on('keypress', handleUsernameInputKeypress);
    $inputText.on('keypress', handleInputTextKeypress);
    $newChannelInput.on('keypress', tc.handleNewChannelInputKeypress);
    $('#connect-image').on('click', connectClientWithUsername);
    $('#add-channel-image').on('click', showAddChannelInput);
    $('#leave-span').on('click', disconnectClient);
    $('#delete-channel-span').on('click', deleteCurrentChannel);
  });

  function handleUsernameInputKeypress(event) {
    if (event.keyCode === 13){
      connectClientWithUsername();
    }
  }

  function handleInputTextKeypress(event) {
    if (event.keyCode === 13) {
      tc.currentChannel.sendMessage($(this).val());
      event.preventDefault();
      $(this).val('');
    }
    else {
      notifyTyping();
    }
  }

  var notifyTyping = $.throttle(function() {
    tc.currentChannel.typing();
  }, 1000);

  tc.handleNewChannelInputKeypress = function(event) {
    if (event.keyCode === 13) {
      tc.messagingClient
        .createChannel({
          friendlyName: $newChannelInput.val(),
        })
        .then(hideAddChannelInput);

      $(this).val('');
      event.preventDefault();
    }
  };

  function connectClientWithUsername() {
    var usernameText = $usernameInput.val();
    $usernameInput.val('');
    if (usernameText == '') {
      alert('Username cannot be empty');
      return;
    }
    tc.username = usernameText;
    fetchAccessToken(tc.username, connectMessagingClient);
  }

  function fetchAccessToken(username, handler) {
    $.post('/token', {identity: username, device: 'browser'}, null, 'json')
      .done(function(response) {
        handler(response.token);
      })
      .fail(function(error) {
        console.log('Failed to fetch the Access Token with error: ' + error);
      });
  }

  function connectMessagingClient(token) {
    // Initialize the IP messaging client
    tc.messagingClient = new Twilio.Chat.Client(token);
    tc.messagingClient.initialize()
      .then(function() {
        updateConnectedUI();
        tc.loadChannelList(tc.joinGeneralChannel);
        tc.messagingClient.on('channelAdded', $.throttle(tc.loadChannelList));
        tc.messagingClient.on('channelRemoved', $.throttle(tc.loadChannelList));
        tc.messagingClient.on('tokenExpired', refreshToken);
      });
  }

  function refreshToken() {
    fetchAccessToken(tc.username, setNewToken);
  }

  function setNewToken(token) {
    tc.messagingClient.updateToken(tokenResponse.token);
  }

  function updateConnectedUI() {
    $('#username-span').text(tc.username);
    $statusRow.addClass('connected').removeClass('disconnected');
    tc.$messageList.addClass('connected').removeClass('disconnected');
    $connectPanel.addClass('connected').removeClass('disconnected');
    $inputText.addClass('with-shadow');
    $typingRow.addClass('connected').removeClass('disconnected');
  }

  tc.loadChannelList = function(handler) {
    if (tc.messagingClient === undefined) {
      console.log('Client is not initialized');
      return;
    }

    tc.messagingClient.getPublicChannels().then(function(channels) {
      tc.channelArray = tc.sortChannelsByName(channels.items);
      $channelList.text('');
      tc.channelArray.forEach(addChannel);
      if (typeof handler === 'function') {
        handler();
      }
    });
  };

  tc.joinGeneralChannel = function() {
    console.log('Attempting to join "general" chat channel...');
    if (!tc.generalChannel) {
      // If it doesn't exist, let's create it
      tc.messagingClient.createChannel({
        uniqueName: GENERAL_CHANNEL_UNIQUE_NAME,
        friendlyName: GENERAL_CHANNEL_NAME
      }).then(function(channel) {
        console.log('Created general channel');
        tc.generalChannel = channel;
        tc.loadChannelList(tc.joinGeneralChannel);
      });
    }
    else {
      console.log('Found general channel:');
      setupChannel(tc.generalChannel);
    }
  };

  function initChannel(channel) {
    console.log('Initialized channel ' + channel.friendlyName);
    return tc.messagingClient.getChannelBySid(channel.sid);
  }

  function joinChannel(_channel) {
    return _channel.join()
      .then(function(joinedChannel) {
        console.log('Joined channel ' + joinedChannel.friendlyName);
        updateChannelUI(_channel);
        tc.currentChannel = _channel;
        tc.loadMessages();
        return joinedChannel;
      });
  }

  function initChannelEvents() {
    console.log(tc.currentChannel.friendlyName + ' ready.');
    tc.currentChannel.on('messageAdded', tc.addMessageToList);
    tc.currentChannel.on('typingStarted', showTypingStarted);
    tc.currentChannel.on('typingEnded', hideTypingStarted);
    tc.currentChannel.on('memberJoined', notifyMemberJoined);
    tc.currentChannel.on('memberLeft', notifyMemberLeft);
    $inputText.prop('disabled', false).focus();
  }

  function setupChannel(channel) {
    return leaveCurrentChannel()
      .then(function() {
        return initChannel(channel);
      })
      .then(function(_channel) {
        return joinChannel(_channel);
      })
      .then(initChannelEvents);
  }

  tc.loadMessages = function() {
    tc.currentChannel.getMessages(MESSAGES_HISTORY_LIMIT).then(function (messages) {
      messages.items.forEach(tc.addMessageToList);
    });
  };

  function leaveCurrentChannel() {
    if (tc.currentChannel) {
      return tc.currentChannel.leave().then(function(leftChannel) {
        console.log('left ' + leftChannel.friendlyName);
        leftChannel.removeListener('messageAdded', tc.addMessageToList);
        leftChannel.removeListener('typingStarted', showTypingStarted);
        leftChannel.removeListener('typingEnded', hideTypingStarted);
        leftChannel.removeListener('memberJoined', notifyMemberJoined);
        leftChannel.removeListener('memberLeft', notifyMemberLeft);
      });
    } else {
      return Promise.resolve();
    }
  }

  tc.addMessageToList = function(message) {
    var rowDiv = $('<div>').addClass('row no-margin');
    rowDiv.loadTemplate($('#message-template'), {
      username: message.author,
      date: dateFormatter.getTodayDate(message.timestamp),
      body: message.body
    });
    if (message.author === tc.username) {
      rowDiv.addClass('own-message');
    }

    tc.$messageList.append(rowDiv);
    scrollToMessageListBottom();
  };

  function notifyMemberJoined(member) {
    notify(member.identity + ' joined the channel')
  }

  function notifyMemberLeft(member) {
    notify(member.identity + ' left the channel');
  }

  function notify(message) {
    var row = $('<div>').addClass('col-md-12');
    row.loadTemplate('#member-notification-template', {
      status: message
    });
    tc.$messageList.append(row);
    scrollToMessageListBottom();
  }

  function showTypingStarted(member) {
    $typingPlaceholder.text(member.identity + ' is typing...');
  }

  function hideTypingStarted(member) {
    $typingPlaceholder.text('');
  }

  function scrollToMessageListBottom() {
    tc.$messageList.scrollTop(tc.$messageList[0].scrollHeight);
  }

  function updateChannelUI(selectedChannel) {
    var channelElements = $('.channel-element').toArray();
    var channelElement = channelElements.filter(function(element) {
      return $(element).data().sid === selectedChannel.sid;
    });
    channelElement = $(channelElement);
    if (tc.currentChannelContainer === undefined && selectedChannel.uniqueName === GENERAL_CHANNEL_UNIQUE_NAME) {
      tc.currentChannelContainer = channelElement;
    }
    tc.currentChannelContainer.removeClass('selected-channel').addClass('unselected-channel');
    channelElement.removeClass('unselected-channel').addClass('selected-channel');
    tc.currentChannelContainer = channelElement;
  }

  function showAddChannelInput() {
    if (tc.messagingClient) {
      $newChannelInputRow.addClass('showing').removeClass('not-showing');
      $channelList.addClass('showing').removeClass('not-showing');
      $newChannelInput.focus();
    }
  }

  function hideAddChannelInput() {
    $newChannelInputRow.addClass('not-showing').removeClass('showing');
    $channelList.addClass('not-showing').removeClass('showing');
    $newChannelInput.val('');
  }

  function addChannel(channel) {
    if (channel.uniqueName === GENERAL_CHANNEL_UNIQUE_NAME) {
      tc.generalChannel = channel;
    }
    var rowDiv = $('<div>').addClass('row channel-row');
    rowDiv.loadTemplate('#channel-template', {
      channelName: channel.friendlyName
    });

    var channelP = rowDiv.children().children().first();

    rowDiv.on('click', selectChannel);
    channelP.data('sid', channel.sid);
    if (tc.currentChannel && channel.sid === tc.currentChannel.sid) {
      tc.currentChannelContainer = channelP;
      channelP.addClass('selected-channel');
    }
    else {
      channelP.addClass('unselected-channel')
    }

    $channelList.append(rowDiv);
  }

  function deleteCurrentChannel() {
    if (!tc.currentChannel) {
      return;
    }

    if (tc.currentChannel.sid === tc.generalChannel.sid) {
      alert('You cannot delete the general channel');
      return;
    }

    tc.currentChannel
      .delete()
      .then(function(channel) {
        console.log('channel: '+ channel.friendlyName + ' deleted');
        setupChannel(tc.generalChannel);
      });
  }

  function selectChannel(event) {
    var target = $(event.target);
    var channelSid = target.data().sid;
    var selectedChannel = tc.channelArray.filter(function(channel) {
      return channel.sid === channelSid;
    })[0];
    if (selectedChannel === tc.currentChannel) {
      return;
    }
    setupChannel(selectedChannel);
  };

  function disconnectClient() {
    leaveCurrentChannel();
    $channelList.text('');
    tc.$messageList.text('');
    channels = undefined;
    $statusRow.addClass('disconnected').removeClass('connected');
    tc.$messageList.addClass('disconnected').removeClass('connected');
    $connectPanel.addClass('disconnected').removeClass('connected');
    $inputText.removeClass('with-shadow');
    $typingRow.addClass('disconnected').removeClass('connected');
  }

  tc.sortChannelsByName = function(channels) {
    return channels.sort(function(a, b) {
      if (a.friendlyName === GENERAL_CHANNEL_NAME) {
        return -1;
      }
      if (b.friendlyName === GENERAL_CHANNEL_NAME) {
        return 1;
      }
      return a.friendlyName.localeCompare(b.friendlyName);
    });
  };

  return tc;
})();
var twiliochat = (function() {
  var tc = {};

  var GENERAL_CHANNEL_UNIQUE_NAME = 'general';
  var GENERAL_CHANNEL_NAME = 'General Channel';
  var MESSAGES_HISTORY_LIMIT = 50;

  var $channelList;
  var $inputText;
  var $usernameInput;
  var $statusRow;
  var $connectPanel;
  var $newChannelInputRow;
  var $newChannelInput;
  var $typingRow;
  var $typingPlaceholder;

  $(document).ready(function() {
    tc.$messageList = $('#message-list');
    $channelList = $('#channel-list');
    $inputText = $('#input-text');
    $usernameInput = $('#username-input');
    $statusRow = $('#status-row');
    $connectPanel = $('#connect-panel');
    $newChannelInputRow = $('#new-channel-input-row');
    $newChannelInput = $('#new-channel-input');
    $typingRow = $('#typing-row');
    $typingPlaceholder = $('#typing-placeholder');
    $usernameInput.focus();
    $usernameInput.on('keypress', handleUsernameInputKeypress);
    $inputText.on('keypress', handleInputTextKeypress);
    $newChannelInput.on('keypress', tc.handleNewChannelInputKeypress);
    $('#connect-image').on('click', connectClientWithUsername);
    $('#add-channel-image').on('click', showAddChannelInput);
    $('#leave-span').on('click', disconnectClient);
    $('#delete-channel-span').on('click', deleteCurrentChannel);
  });

  function handleUsernameInputKeypress(event) {
    if (event.keyCode === 13){
      connectClientWithUsername();
    }
  }

  function handleInputTextKeypress(event) {
    if (event.keyCode === 13) {
      tc.currentChannel.sendMessage($(this).val());
      event.preventDefault();
      $(this).val('');
    }
    else {
      notifyTyping();
    }
  }

  var notifyTyping = $.throttle(function() {
    tc.currentChannel.typing();
  }, 1000);

  tc.handleNewChannelInputKeypress = function(event) {
    if (event.keyCode === 13) {
      tc.messagingClient
        .createChannel({
          friendlyName: $newChannelInput.val(),
        })
        .then(hideAddChannelInput);

      $(this).val('');
      event.preventDefault();
    }
  };

  function connectClientWithUsername() {
    var usernameText = $usernameInput.val();
    $usernameInput.val('');
    if (usernameText == '') {
      alert('Username cannot be empty');
      return;
    }
    tc.username = usernameText;
    fetchAccessToken(tc.username, connectMessagingClient);
  }

  function fetchAccessToken(username, handler) {
    $.post('/token', {identity: username, device: 'browser'}, null, 'json')
      .done(function(response) {
        handler(response.token);
      })
      .fail(function(error) {
        console.log('Failed to fetch the Access Token with error: ' + error);
      });
  }

  function connectMessagingClient(token) {
    // Initialize the IP messaging client
    tc.messagingClient = new Twilio.Chat.Client(token);
    tc.messagingClient.initialize()
      .then(function() {
        updateConnectedUI();
        tc.loadChannelList(tc.joinGeneralChannel);
        tc.messagingClient.on('channelAdded', $.throttle(tc.loadChannelList));
        tc.messagingClient.on('channelRemoved', $.throttle(tc.loadChannelList));
        tc.messagingClient.on('tokenExpired', refreshToken);
      });
  }

  function refreshToken() {
    fetchAccessToken(tc.username, setNewToken);
  }

  function setNewToken(token) {
    tc.messagingClient.updateToken(tokenResponse.token);
  }

  function updateConnectedUI() {
    $('#username-span').text(tc.username);
    $statusRow.addClass('connected').removeClass('disconnected');
    tc.$messageList.addClass('connected').removeClass('disconnected');
    $connectPanel.addClass('connected').removeClass('disconnected');
    $inputText.addClass('with-shadow');
    $typingRow.addClass('connected').removeClass('disconnected');
  }

  tc.loadChannelList = function(handler) {
    if (tc.messagingClient === undefined) {
      console.log('Client is not initialized');
      return;
    }

    tc.messagingClient.getPublicChannels().then(function(channels) {
      tc.channelArray = tc.sortChannelsByName(channels.items);
      $channelList.text('');
      tc.channelArray.forEach(addChannel);
      if (typeof handler === 'function') {
        handler();
      }
    });
  };

  tc.joinGeneralChannel = function() {
    console.log('Attempting to join "general" chat channel...');
    if (!tc.generalChannel) {
      // If it doesn't exist, let's create it
      tc.messagingClient.createChannel({
        uniqueName: GENERAL_CHANNEL_UNIQUE_NAME,
        friendlyName: GENERAL_CHANNEL_NAME
      }).then(function(channel) {
        console.log('Created general channel');
        tc.generalChannel = channel;
        tc.loadChannelList(tc.joinGeneralChannel);
      });
    }
    else {
      console.log('Found general channel:');
      setupChannel(tc.generalChannel);
    }
  };

  function initChannel(channel) {
    console.log('Initialized channel ' + channel.friendlyName);
    return tc.messagingClient.getChannelBySid(channel.sid);
  }

  function joinChannel(_channel) {
    return _channel.join()
      .then(function(joinedChannel) {
        console.log('Joined channel ' + joinedChannel.friendlyName);
        updateChannelUI(_channel);
        tc.currentChannel = _channel;
        tc.loadMessages();
        return joinedChannel;
      });
  }

  function initChannelEvents() {
    console.log(tc.currentChannel.friendlyName + ' ready.');
    tc.currentChannel.on('messageAdded', tc.addMessageToList);
    tc.currentChannel.on('typingStarted', showTypingStarted);
    tc.currentChannel.on('typingEnded', hideTypingStarted);
    tc.currentChannel.on('memberJoined', notifyMemberJoined);
    tc.currentChannel.on('memberLeft', notifyMemberLeft);
    $inputText.prop('disabled', false).focus();
  }

  function setupChannel(channel) {
    return leaveCurrentChannel()
      .then(function() {
        return initChannel(channel);
      })
      .then(function(_channel) {
        return joinChannel(_channel);
      })
      .then(initChannelEvents);
  }

  tc.loadMessages = function() {
    tc.currentChannel.getMessages(MESSAGES_HISTORY_LIMIT).then(function (messages) {
      messages.items.forEach(tc.addMessageToList);
    });
  };

  function leaveCurrentChannel() {
    if (tc.currentChannel) {
      return tc.currentChannel.leave().then(function(leftChannel) {
        console.log('left ' + leftChannel.friendlyName);
        leftChannel.removeListener('messageAdded', tc.addMessageToList);
        leftChannel.removeListener('typingStarted', showTypingStarted);
        leftChannel.removeListener('typingEnded', hideTypingStarted);
        leftChannel.removeListener('memberJoined', notifyMemberJoined);
        leftChannel.removeListener('memberLeft', notifyMemberLeft);
      });
    } else {
      return Promise.resolve();
    }
  }

  tc.addMessageToList = function(message) {
    var rowDiv = $('<div>').addClass('row no-margin');
    rowDiv.loadTemplate($('#message-template'), {
      username: message.author,
      date: dateFormatter.getTodayDate(message.timestamp),
      body: message.body
    });
    if (message.author === tc.username) {
      rowDiv.addClass('own-message');
    }

    tc.$messageList.append(rowDiv);
    scrollToMessageListBottom();
  };

  function notifyMemberJoined(member) {
    notify(member.identity + ' joined the channel')
  }

  function notifyMemberLeft(member) {
    notify(member.identity + ' left the channel');
  }

  function notify(message) {
    var row = $('<div>').addClass('col-md-12');
    row.loadTemplate('#member-notification-template', {
      status: message
    });
    tc.$messageList.append(row);
    scrollToMessageListBottom();
  }

  function showTypingStarted(member) {
    $typingPlaceholder.text(member.identity + ' is typing...');
  }

  function hideTypingStarted(member) {
    $typingPlaceholder.text('');
  }

  function scrollToMessageListBottom() {
    tc.$messageList.scrollTop(tc.$messageList[0].scrollHeight);
  }

  function updateChannelUI(selectedChannel) {
    var channelElements = $('.channel-element').toArray();
    var channelElement = channelElements.filter(function(element) {
      return $(element).data().sid === selectedChannel.sid;
    });
    channelElement = $(channelElement);
    if (tc.currentChannelContainer === undefined && selectedChannel.uniqueName === GENERAL_CHANNEL_UNIQUE_NAME) {
      tc.currentChannelContainer = channelElement;
    }
    tc.currentChannelContainer.removeClass('selected-channel').addClass('unselected-channel');
    channelElement.removeClass('unselected-channel').addClass('selected-channel');
    tc.currentChannelContainer = channelElement;
  }

  function showAddChannelInput() {
    if (tc.messagingClient) {
      $newChannelInputRow.addClass('showing').removeClass('not-showing');
      $channelList.addClass('showing').removeClass('not-showing');
      $newChannelInput.focus();
    }
  }

  function hideAddChannelInput() {
    $newChannelInputRow.addClass('not-showing').removeClass('showing');
    $channelList.addClass('not-showing').removeClass('showing');
    $newChannelInput.val('');
  }

  function addChannel(channel) {
    if (channel.uniqueName === GENERAL_CHANNEL_UNIQUE_NAME) {
      tc.generalChannel = channel;
    }
    var rowDiv = $('<div>').addClass('row channel-row');
    rowDiv.loadTemplate('#channel-template', {
      channelName: channel.friendlyName
    });

    var channelP = rowDiv.children().children().first();

    rowDiv.on('click', selectChannel);
    channelP.data('sid', channel.sid);
    if (tc.currentChannel && channel.sid === tc.currentChannel.sid) {
      tc.currentChannelContainer = channelP;
      channelP.addClass('selected-channel');
    }
    else {
      channelP.addClass('unselected-channel')
    }

    $channelList.append(rowDiv);
  }

  function deleteCurrentChannel() {
    if (!tc.currentChannel) {
      return;
    }

    if (tc.currentChannel.sid === tc.generalChannel.sid) {
      alert('You cannot delete the general channel');
      return;
    }

    tc.currentChannel
      .delete()
      .then(function(channel) {
        console.log('channel: '+ channel.friendlyName + ' deleted');
        setupChannel(tc.generalChannel);
      });
  }

  function selectChannel(event) {
    var target = $(event.target);
    var channelSid = target.data().sid;
    var selectedChannel = tc.channelArray.filter(function(channel) {
      return channel.sid === channelSid;
    })[0];
    if (selectedChannel === tc.currentChannel) {
      return;
    }
    setupChannel(selectedChannel);
  };

  function disconnectClient() {
    leaveCurrentChannel();
    $channelList.text('');
    tc.$messageList.text('');
    channels = undefined;
    $statusRow.addClass('disconnected').removeClass('connected');
    tc.$messageList.addClass('disconnected').removeClass('connected');
    $connectPanel.addClass('disconnected').removeClass('connected');
    $inputText.removeClass('with-shadow');
    $typingRow.addClass('disconnected').removeClass('connected');
  }

  tc.sortChannelsByName = function(channels) {
    return channels.sort(function(a, b) {
      if (a.friendlyName === GENERAL_CHANNEL_NAME) {
        return -1;
      }
      if (b.friendlyName === GENERAL_CHANNEL_NAME) {
        return 1;
      }
      return a.friendlyName.localeCompare(b.friendlyName);
    });
  };

  return tc;
})();
var twiliochat = (function() {
  var tc = {};

  var GENERAL_CHANNEL_UNIQUE_NAME = 'general';
  var GENERAL_CHANNEL_NAME = 'General Channel';
  var MESSAGES_HISTORY_LIMIT = 50;

  var $channelList;
  var $inputText;
  var $usernameInput;
  var $statusRow;
  var $connectPanel;
  var $newChannelInputRow;
  var $newChannelInput;
  var $typingRow;
  var $typingPlaceholder;

  $(document).ready(function() {
    tc.$messageList = $('#message-list');
    $channelList = $('#channel-list');
    $inputText = $('#input-text');
    $usernameInput = $('#username-input');
    $statusRow = $('#status-row');
    $connectPanel = $('#connect-panel');
    $newChannelInputRow = $('#new-channel-input-row');
    $newChannelInput = $('#new-channel-input');
    $typingRow = $('#typing-row');
    $typingPlaceholder = $('#typing-placeholder');
    $usernameInput.focus();
    $usernameInput.on('keypress', handleUsernameInputKeypress);
    $inputText.on('keypress', handleInputTextKeypress);
    $newChannelInput.on('keypress', tc.handleNewChannelInputKeypress);
    $('#connect-image').on('click', connectClientWithUsername);
    $('#add-channel-image').on('click', showAddChannelInput);
    $('#leave-span').on('click', disconnectClient);
    $('#delete-channel-span').on('click', deleteCurrentChannel);
  });

  function handleUsernameInputKeypress(event) {
    if (event.keyCode === 13){
      connectClientWithUsername();
    }
  }

  function handleInputTextKeypress(event) {
    if (event.keyCode === 13) {
      tc.currentChannel.sendMessage($(this).val());
      event.preventDefault();
      $(this).val('');
    }
    else {
      notifyTyping();
    }
  }

  var notifyTyping = $.throttle(function() {
    tc.currentChannel.typing();
  }, 1000);

  tc.handleNewChannelInputKeypress = function(event) {
    if (event.keyCode === 13) {
      tc.messagingClient
        .createChannel({
          friendlyName: $newChannelInput.val(),
        })
        .then(hideAddChannelInput);

      $(this).val('');
      event.preventDefault();
    }
  };

  function connectClientWithUsername() {
    var usernameText = $usernameInput.val();
    $usernameInput.val('');
    if (usernameText == '') {
      alert('Username cannot be empty');
      return;
    }
    tc.username = usernameText;
    fetchAccessToken(tc.username, connectMessagingClient);
  }

  function fetchAccessToken(username, handler) {
    $.post('/token', {identity: username, device: 'browser'}, null, 'json')
      .done(function(response) {
        handler(response.token);
      })
      .fail(function(error) {
        console.log('Failed to fetch the Access Token with error: ' + error);
      });
  }

  function connectMessagingClient(token) {
    // Initialize the IP messaging client
    tc.messagingClient = new Twilio.Chat.Client(token);
    tc.messagingClient.initialize()
      .then(function() {
        updateConnectedUI();
        tc.loadChannelList(tc.joinGeneralChannel);
        tc.messagingClient.on('channelAdded', $.throttle(tc.loadChannelList));
        tc.messagingClient.on('channelRemoved', $.throttle(tc.loadChannelList));
        tc.messagingClient.on('tokenExpired', refreshToken);
      });
  }

  function refreshToken() {
    fetchAccessToken(tc.username, setNewToken);
  }

  function setNewToken(token) {
    tc.messagingClient.updateToken(tokenResponse.token);
  }

  function updateConnectedUI() {
    $('#username-span').text(tc.username);
    $statusRow.addClass('connected').removeClass('disconnected');
    tc.$messageList.addClass('connected').removeClass('disconnected');
    $connectPanel.addClass('connected').removeClass('disconnected');
    $inputText.addClass('with-shadow');
    $typingRow.addClass('connected').removeClass('disconnected');
  }

  tc.loadChannelList = function(handler) {
    if (tc.messagingClient === undefined) {
      console.log('Client is not initialized');
      return;
    }

    tc.messagingClient.getPublicChannels().then(function(channels) {
      tc.channelArray = tc.sortChannelsByName(channels.items);
      $channelList.text('');
      tc.channelArray.forEach(addChannel);
      if (typeof handler === 'function') {
        handler();
      }
    });
  };

  tc.joinGeneralChannel = function() {
    console.log('Attempting to join "general" chat channel...');
    if (!tc.generalChannel) {
      // If it doesn't exist, let's create it
      tc.messagingClient.createChannel({
        uniqueName: GENERAL_CHANNEL_UNIQUE_NAME,
        friendlyName: GENERAL_CHANNEL_NAME
      }).then(function(channel) {
        console.log('Created general channel');
        tc.generalChannel = channel;
        tc.loadChannelList(tc.joinGeneralChannel);
      });
    }
    else {
      console.log('Found general channel:');
      setupChannel(tc.generalChannel);
    }
  };

  function initChannel(channel) {
    console.log('Initialized channel ' + channel.friendlyName);
    return tc.messagingClient.getChannelBySid(channel.sid);
  }

  function joinChannel(_channel) {
    return _channel.join()
      .then(function(joinedChannel) {
        console.log('Joined channel ' + joinedChannel.friendlyName);
        updateChannelUI(_channel);
        tc.currentChannel = _channel;
        tc.loadMessages();
        return joinedChannel;
      });
  }

  function initChannelEvents() {
    console.log(tc.currentChannel.friendlyName + ' ready.');
    tc.currentChannel.on('messageAdded', tc.addMessageToList);
    tc.currentChannel.on('typingStarted', showTypingStarted);
    tc.currentChannel.on('typingEnded', hideTypingStarted);
    tc.currentChannel.on('memberJoined', notifyMemberJoined);
    tc.currentChannel.on('memberLeft', notifyMemberLeft);
    $inputText.prop('disabled', false).focus();
  }

  function setupChannel(channel) {
    return leaveCurrentChannel()
      .then(function() {
        return initChannel(channel);
      })
      .then(function(_channel) {
        return joinChannel(_channel);
      })
      .then(initChannelEvents);
  }

  tc.loadMessages = function() {
    tc.currentChannel.getMessages(MESSAGES_HISTORY_LIMIT).then(function (messages) {
      messages.items.forEach(tc.addMessageToList);
    });
  };

  function leaveCurrentChannel() {
    if (tc.currentChannel) {
      return tc.currentChannel.leave().then(function(leftChannel) {
        console.log('left ' + leftChannel.friendlyName);
        leftChannel.removeListener('messageAdded', tc.addMessageToList);
        leftChannel.removeListener('typingStarted', showTypingStarted);
        leftChannel.removeListener('typingEnded', hideTypingStarted);
        leftChannel.removeListener('memberJoined', notifyMemberJoined);
        leftChannel.removeListener('memberLeft', notifyMemberLeft);
      });
    } else {
      return Promise.resolve();
    }
  }

  tc.addMessageToList = function(message) {
    var rowDiv = $('<div>').addClass('row no-margin');
    rowDiv.loadTemplate($('#message-template'), {
      username: message.author,
      date: dateFormatter.getTodayDate(message.timestamp),
      body: message.body
    });
    if (message.author === tc.username) {
      rowDiv.addClass('own-message');
    }

    tc.$messageList.append(rowDiv);
    scrollToMessageListBottom();
  };

  function notifyMemberJoined(member) {
    notify(member.identity + ' joined the channel')
  }

  function notifyMemberLeft(member) {
    notify(member.identity + ' left the channel');
  }

  function notify(message) {
    var row = $('<div>').addClass('col-md-12');
    row.loadTemplate('#member-notification-template', {
      status: message
    });
    tc.$messageList.append(row);
    scrollToMessageListBottom();
  }

  function showTypingStarted(member) {
    $typingPlaceholder.text(member.identity + ' is typing...');
  }

  function hideTypingStarted(member) {
    $typingPlaceholder.text('');
  }

  function scrollToMessageListBottom() {
    tc.$messageList.scrollTop(tc.$messageList[0].scrollHeight);
  }

  function updateChannelUI(selectedChannel) {
    var channelElements = $('.channel-element').toArray();
    var channelElement = channelElements.filter(function(element) {
      return $(element).data().sid === selectedChannel.sid;
    });
    channelElement = $(channelElement);
    if (tc.currentChannelContainer === undefined && selectedChannel.uniqueName === GENERAL_CHANNEL_UNIQUE_NAME) {
      tc.currentChannelContainer = channelElement;
    }
    tc.currentChannelContainer.removeClass('selected-channel').addClass('unselected-channel');
    channelElement.removeClass('unselected-channel').addClass('selected-channel');
    tc.currentChannelContainer = channelElement;
  }

  function showAddChannelInput() {
    if (tc.messagingClient) {
      $newChannelInputRow.addClass('showing').removeClass('not-showing');
      $channelList.addClass('showing').removeClass('not-showing');
      $newChannelInput.focus();
    }
  }

  function hideAddChannelInput() {
    $newChannelInputRow.addClass('not-showing').removeClass('showing');
    $channelList.addClass('not-showing').removeClass('showing');
    $newChannelInput.val('');
  }

  function addChannel(channel) {
    if (channel.uniqueName === GENERAL_CHANNEL_UNIQUE_NAME) {
      tc.generalChannel = channel;
    }
    var rowDiv = $('<div>').addClass('row channel-row');
    rowDiv.loadTemplate('#channel-template', {
      channelName: channel.friendlyName
    });

    var channelP = rowDiv.children().children().first();

    rowDiv.on('click', selectChannel);
    channelP.data('sid', channel.sid);
    if (tc.currentChannel && channel.sid === tc.currentChannel.sid) {
      tc.currentChannelContainer = channelP;
      channelP.addClass('selected-channel');
    }
    else {
      channelP.addClass('unselected-channel')
    }

    $channelList.append(rowDiv);
  }

  function deleteCurrentChannel() {
    if (!tc.currentChannel) {
      return;
    }

    if (tc.currentChannel.sid === tc.generalChannel.sid) {
      alert('You cannot delete the general channel');
      return;
    }

    tc.currentChannel
      .delete()
      .then(function(channel) {
        console.log('channel: '+ channel.friendlyName + ' deleted');
        setupChannel(tc.generalChannel);
      });
  }

  function selectChannel(event) {
    var target = $(event.target);
    var channelSid = target.data().sid;
    var selectedChannel = tc.channelArray.filter(function(channel) {
      return channel.sid === channelSid;
    })[0];
    if (selectedChannel === tc.currentChannel) {
      return;
    }
    setupChannel(selectedChannel);
  };

  function disconnectClient() {
    leaveCurrentChannel();
    $channelList.text('');
    tc.$messageList.text('');
    channels = undefined;
    $statusRow.addClass('disconnected').removeClass('connected');
    tc.$messageList.addClass('disconnected').removeClass('connected');
    $connectPanel.addClass('disconnected').removeClass('connected');
    $inputText.removeClass('with-shadow');
    $typingRow.addClass('disconnected').removeClass('connected');
  }

  tc.sortChannelsByName = function(channels) {
    return channels.sort(function(a, b) {
      if (a.friendlyName === GENERAL_CHANNEL_NAME) {
        return -1;
      }
      if (b.friendlyName === GENERAL_CHANNEL_NAME) {
        return 1;
      }
      return a.friendlyName.localeCompare(b.friendlyName);
    });
  };

  return tc;
})();
var twiliochat = (function() {
  var tc = {};

  var GENERAL_CHANNEL_UNIQUE_NAME = 'general';
  var GENERAL_CHANNEL_NAME = 'General Channel';
  var MESSAGES_HISTORY_LIMIT = 50;

  var $channelList;
  var $inputText;
  var $usernameInput;
  var $statusRow;
  var $connectPanel;
  var $newChannelInputRow;
  var $newChannelInput;
  var $typingRow;
  var $typingPlaceholder;

  $(document).ready(function() {
    tc.$messageList = $('#message-list');
    $channelList = $('#channel-list');
    $inputText = $('#input-text');
    $usernameInput = $('#username-input');
    $statusRow = $('#status-row');
    $connectPanel = $('#connect-panel');
    $newChannelInputRow = $('#new-channel-input-row');
    $newChannelInput = $('#new-channel-input');
    $typingRow = $('#typing-row');
    $typingPlaceholder = $('#typing-placeholder');
    $usernameInput.focus();
    $usernameInput.on('keypress', handleUsernameInputKeypress);
    $inputText.on('keypress', handleInputTextKeypress);
    $newChannelInput.on('keypress', tc.handleNewChannelInputKeypress);
    $('#connect-image').on('click', connectClientWithUsername);
    $('#add-channel-image').on('click', showAddChannelInput);
    $('#leave-span').on('click', disconnectClient);
    $('#delete-channel-span').on('click', deleteCurrentChannel);
  });

  function handleUsernameInputKeypress(event) {
    if (event.keyCode === 13){
      connectClientWithUsername();
    }
  }

  function handleInputTextKeypress(event) {
    if (event.keyCode === 13) {
      tc.currentChannel.sendMessage($(this).val());
      event.preventDefault();
      $(this).val('');
    }
    else {
      notifyTyping();
    }
  }

  var notifyTyping = $.throttle(function() {
    tc.currentChannel.typing();
  }, 1000);

  tc.handleNewChannelInputKeypress = function(event) {
    if (event.keyCode === 13) {
      tc.messagingClient
        .createChannel({
          friendlyName: $newChannelInput.val(),
        })
        .then(hideAddChannelInput);

      $(this).val('');
      event.preventDefault();
    }
  };

  function connectClientWithUsername() {
    var usernameText = $usernameInput.val();
    $usernameInput.val('');
    if (usernameText == '') {
      alert('Username cannot be empty');
      return;
    }
    tc.username = usernameText;
    fetchAccessToken(tc.username, connectMessagingClient);
  }

  function fetchAccessToken(username, handler) {
    $.post('/token', {identity: username, device: 'browser'}, null, 'json')
      .done(function(response) {
        handler(response.token);
      })
      .fail(function(error) {
        console.log('Failed to fetch the Access Token with error: ' + error);
      });
  }

  function connectMessagingClient(token) {
    // Initialize the IP messaging client
    tc.messagingClient = new Twilio.Chat.Client(token);
    tc.messagingClient.initialize()
      .then(function() {
        updateConnectedUI();
        tc.loadChannelList(tc.joinGeneralChannel);
        tc.messagingClient.on('channelAdded', $.throttle(tc.loadChannelList));
        tc.messagingClient.on('channelRemoved', $.throttle(tc.loadChannelList));
        tc.messagingClient.on('tokenExpired', refreshToken);
      });
  }

  function refreshToken() {
    fetchAccessToken(tc.username, setNewToken);
  }

  function setNewToken(token) {
    tc.messagingClient.updateToken(tokenResponse.token);
  }

  function updateConnectedUI() {
    $('#username-span').text(tc.username);
    $statusRow.addClass('connected').removeClass('disconnected');
    tc.$messageList.addClass('connected').removeClass('disconnected');
    $connectPanel.addClass('connected').removeClass('disconnected');
    $inputText.addClass('with-shadow');
    $typingRow.addClass('connected').removeClass('disconnected');
  }

  tc.loadChannelList = function(handler) {
    if (tc.messagingClient === undefined) {
      console.log('Client is not initialized');
      return;
    }

    tc.messagingClient.getPublicChannels().then(function(channels) {
      tc.channelArray = tc.sortChannelsByName(channels.items);
      $channelList.text('');
      tc.channelArray.forEach(addChannel);
      if (typeof handler === 'function') {
        handler();
      }
    });
  };

  tc.joinGeneralChannel = function() {
    console.log('Attempting to join "general" chat channel...');
    if (!tc.generalChannel) {
      // If it doesn't exist, let's create it
      tc.messagingClient.createChannel({
        uniqueName: GENERAL_CHANNEL_UNIQUE_NAME,
        friendlyName: GENERAL_CHANNEL_NAME
      }).then(function(channel) {
        console.log('Created general channel');
        tc.generalChannel = channel;
        tc.loadChannelList(tc.joinGeneralChannel);
      });
    }
    else {
      console.log('Found general channel:');
      setupChannel(tc.generalChannel);
    }
  };

  function initChannel(channel) {
    console.log('Initialized channel ' + channel.friendlyName);
    return tc.messagingClient.getChannelBySid(channel.sid);
  }

  function joinChannel(_channel) {
    return _channel.join()
      .then(function(joinedChannel) {
        console.log('Joined channel ' + joinedChannel.friendlyName);
        updateChannelUI(_channel);
        tc.currentChannel = _channel;
        tc.loadMessages();
        return joinedChannel;
      });
  }

  function initChannelEvents() {
    console.log(tc.currentChannel.friendlyName + ' ready.');
    tc.currentChannel.on('messageAdded', tc.addMessageToList);
    tc.currentChannel.on('typingStarted', showTypingStarted);
    tc.currentChannel.on('typingEnded', hideTypingStarted);
    tc.currentChannel.on('memberJoined', notifyMemberJoined);
    tc.currentChannel.on('memberLeft', notifyMemberLeft);
    $inputText.prop('disabled', false).focus();
  }

  function setupChannel(channel) {
    return leaveCurrentChannel()
      .then(function() {
        return initChannel(channel);
      })
      .then(function(_channel) {
        return joinChannel(_channel);
      })
      .then(initChannelEvents);
  }

  tc.loadMessages = function() {
    tc.currentChannel.getMessages(MESSAGES_HISTORY_LIMIT).then(function (messages) {
      messages.items.forEach(tc.addMessageToList);
    });
  };

  function leaveCurrentChannel() {
    if (tc.currentChannel) {
      return tc.currentChannel.leave().then(function(leftChannel) {
        console.log('left ' + leftChannel.friendlyName);
        leftChannel.removeListener('messageAdded', tc.addMessageToList);
        leftChannel.removeListener('typingStarted', showTypingStarted);
        leftChannel.removeListener('typingEnded', hideTypingStarted);
        leftChannel.removeListener('memberJoined', notifyMemberJoined);
        leftChannel.removeListener('memberLeft', notifyMemberLeft);
      });
    } else {
      return Promise.resolve();
    }
  }

  tc.addMessageToList = function(message) {
    var rowDiv = $('<div>').addClass('row no-margin');
    rowDiv.loadTemplate($('#message-template'), {
      username: message.author,
      date: dateFormatter.getTodayDate(message.timestamp),
      body: message.body
    });
    if (message.author === tc.username) {
      rowDiv.addClass('own-message');
    }

    tc.$messageList.append(rowDiv);
    scrollToMessageListBottom();
  };

  function notifyMemberJoined(member) {
    notify(member.identity + ' joined the channel')
  }

  function notifyMemberLeft(member) {
    notify(member.identity + ' left the channel');
  }

  function notify(message) {
    var row = $('<div>').addClass('col-md-12');
    row.loadTemplate('#member-notification-template', {
      status: message
    });
    tc.$messageList.append(row);
    scrollToMessageListBottom();
  }

  function showTypingStarted(member) {
    $typingPlaceholder.text(member.identity + ' is typing...');
  }

  function hideTypingStarted(member) {
    $typingPlaceholder.text('');
  }

  function scrollToMessageListBottom() {
    tc.$messageList.scrollTop(tc.$messageList[0].scrollHeight);
  }

  function updateChannelUI(selectedChannel) {
    var channelElements = $('.channel-element').toArray();
    var channelElement = channelElements.filter(function(element) {
      return $(element).data().sid === selectedChannel.sid;
    });
    channelElement = $(channelElement);
    if (tc.currentChannelContainer === undefined && selectedChannel.uniqueName === GENERAL_CHANNEL_UNIQUE_NAME) {
      tc.currentChannelContainer = channelElement;
    }
    tc.currentChannelContainer.removeClass('selected-channel').addClass('unselected-channel');
    channelElement.removeClass('unselected-channel').addClass('selected-channel');
    tc.currentChannelContainer = channelElement;
  }

  function showAddChannelInput() {
    if (tc.messagingClient) {
      $newChannelInputRow.addClass('showing').removeClass('not-showing');
      $channelList.addClass('showing').removeClass('not-showing');
      $newChannelInput.focus();
    }
  }

  function hideAddChannelInput() {
    $newChannelInputRow.addClass('not-showing').removeClass('showing');
    $channelList.addClass('not-showing').removeClass('showing');
    $newChannelInput.val('');
  }

  function addChannel(channel) {
    if (channel.uniqueName === GENERAL_CHANNEL_UNIQUE_NAME) {
      tc.generalChannel = channel;
    }
    var rowDiv = $('<div>').addClass('row channel-row');
    rowDiv.loadTemplate('#channel-template', {
      channelName: channel.friendlyName
    });

    var channelP = rowDiv.children().children().first();

    rowDiv.on('click', selectChannel);
    channelP.data('sid', channel.sid);
    if (tc.currentChannel && channel.sid === tc.currentChannel.sid) {
      tc.currentChannelContainer = channelP;
      channelP.addClass('selected-channel');
    }
    else {
      channelP.addClass('unselected-channel')
    }

    $channelList.append(rowDiv);
  }

  function deleteCurrentChannel() {
    if (!tc.currentChannel) {
      return;
    }

    if (tc.currentChannel.sid === tc.generalChannel.sid) {
      alert('You cannot delete the general channel');
      return;
    }

    tc.currentChannel
      .delete()
      .then(function(channel) {
        console.log('channel: '+ channel.friendlyName + ' deleted');
        setupChannel(tc.generalChannel);
      });
  }

  function selectChannel(event) {
    var target = $(event.target);
    var channelSid = target.data().sid;
    var selectedChannel = tc.channelArray.filter(function(channel) {
      return channel.sid === channelSid;
    })[0];
    if (selectedChannel === tc.currentChannel) {
      return;
    }
    setupChannel(selectedChannel);
  };

  function disconnectClient() {
    leaveCurrentChannel();
    $channelList.text('');
    tc.$messageList.text('');
    channels = undefined;
    $statusRow.addClass('disconnected').removeClass('connected');
    tc.$messageList.addClass('disconnected').removeClass('connected');
    $connectPanel.addClass('disconnected').removeClass('connected');
    $inputText.removeClass('with-shadow');
    $typingRow.addClass('disconnected').removeClass('connected');
  }

  tc.sortChannelsByName = function(channels) {
    return channels.sort(function(a, b) {
      if (a.friendlyName === GENERAL_CHANNEL_NAME) {
        return -1;
      }
      if (b.friendlyName === GENERAL_CHANNEL_NAME) {
        return 1;
      }
      return a.friendlyName.localeCompare(b.friendlyName);
    });
  };

  return tc;
})();
var twiliochat = (function() {
  var tc = {};

  var GENERAL_CHANNEL_UNIQUE_NAME = 'general';
  var GENERAL_CHANNEL_NAME = 'General Channel';
  var MESSAGES_HISTORY_LIMIT = 50;

  var $channelList;
  var $inputText;
  var $usernameInput;
  var $statusRow;
  var $connectPanel;
  var $newChannelInputRow;
  var $newChannelInput;
  var $typingRow;
  var $typingPlaceholder;

  $(document).ready(function() {
    tc.$messageList = $('#message-list');
    $channelList = $('#channel-list');
    $inputText = $('#input-text');
    $usernameInput = $('#username-input');
    $statusRow = $('#status-row');
    $connectPanel = $('#connect-panel');
    $newChannelInputRow = $('#new-channel-input-row');
    $newChannelInput = $('#new-channel-input');
    $typingRow = $('#typing-row');
    $typingPlaceholder = $('#typing-placeholder');
    $usernameInput.focus();
    $usernameInput.on('keypress', handleUsernameInputKeypress);
    $inputText.on('keypress', handleInputTextKeypress);
    $newChannelInput.on('keypress', tc.handleNewChannelInputKeypress);
    $('#connect-image').on('click', connectClientWithUsername);
    $('#add-channel-image').on('click', showAddChannelInput);
    $('#leave-span').on('click', disconnectClient);
    $('#delete-channel-span').on('click', deleteCurrentChannel);
  });

  function handleUsernameInputKeypress(event) {
    if (event.keyCode === 13){
      connectClientWithUsername();
    }
  }

  function handleInputTextKeypress(event) {
    if (event.keyCode === 13) {
      tc.currentChannel.sendMessage($(this).val());
      event.preventDefault();
      $(this).val('');
    }
    else {
      notifyTyping();
    }
  }

  var notifyTyping = $.throttle(function() {
    tc.currentChannel.typing();
  }, 1000);

  tc.handleNewChannelInputKeypress = function(event) {
    if (event.keyCode === 13) {
      tc.messagingClient
        .createChannel({
          friendlyName: $newChannelInput.val(),
        })
        .then(hideAddChannelInput);

      $(this).val('');
      event.preventDefault();
    }
  };

  function connectClientWithUsername() {
    var usernameText = $usernameInput.val();
    $usernameInput.val('');
    if (usernameText == '') {
      alert('Username cannot be empty');
      return;
    }
    tc.username = usernameText;
    fetchAccessToken(tc.username, connectMessagingClient);
  }

  function fetchAccessToken(username, handler) {
    $.post('/token', {identity: username, device: 'browser'}, null, 'json')
      .done(function(response) {
        handler(response.token);
      })
      .fail(function(error) {
        console.log('Failed to fetch the Access Token with error: ' + error);
      });
  }

  function connectMessagingClient(token) {
    // Initialize the IP messaging client
    tc.messagingClient = new Twilio.Chat.Client(token);
    tc.messagingClient.initialize()
      .then(function() {
        updateConnectedUI();
        tc.loadChannelList(tc.joinGeneralChannel);
        tc.messagingClient.on('channelAdded', $.throttle(tc.loadChannelList));
        tc.messagingClient.on('channelRemoved', $.throttle(tc.loadChannelList));
        tc.messagingClient.on('tokenExpired', refreshToken);
      });
  }

  function refreshToken() {
    fetchAccessToken(tc.username, setNewToken);
  }

  function setNewToken(token) {
    tc.messagingClient.updateToken(tokenResponse.token);
  }

  function updateConnectedUI() {
    $('#username-span').text(tc.username);
    $statusRow.addClass('connected').removeClass('disconnected');
    tc.$messageList.addClass('connected').removeClass('disconnected');
    $connectPanel.addClass('connected').removeClass('disconnected');
    $inputText.addClass('with-shadow');
    $typingRow.addClass('connected').removeClass('disconnected');
  }

  tc.loadChannelList = function(handler) {
    if (tc.messagingClient === undefined) {
      console.log('Client is not initialized');
      return;
    }

    tc.messagingClient.getPublicChannels().then(function(channels) {
      tc.channelArray = tc.sortChannelsByName(channels.items);
      $channelList.text('');
      tc.channelArray.forEach(addChannel);
      if (typeof handler === 'function') {
        handler();
      }
    });
  };

  tc.joinGeneralChannel = function() {
    console.log('Attempting to join "general" chat channel...');
    if (!tc.generalChannel) {
      // If it doesn't exist, let's create it
      tc.messagingClient.createChannel({
        uniqueName: GENERAL_CHANNEL_UNIQUE_NAME,
        friendlyName: GENERAL_CHANNEL_NAME
      }).then(function(channel) {
        console.log('Created general channel');
        tc.generalChannel = channel;
        tc.loadChannelList(tc.joinGeneralChannel);
      });
    }
    else {
      console.log('Found general channel:');
      setupChannel(tc.generalChannel);
    }
  };

  function initChannel(channel) {
    console.log('Initialized channel ' + channel.friendlyName);
    return tc.messagingClient.getChannelBySid(channel.sid);
  }

  function joinChannel(_channel) {
    return _channel.join()
      .then(function(joinedChannel) {
        console.log('Joined channel ' + joinedChannel.friendlyName);
        updateChannelUI(_channel);
        tc.currentChannel = _channel;
        tc.loadMessages();
        return joinedChannel;
      });
  }

  function initChannelEvents() {
    console.log(tc.currentChannel.friendlyName + ' ready.');
    tc.currentChannel.on('messageAdded', tc.addMessageToList);
    tc.currentChannel.on('typingStarted', showTypingStarted);
    tc.currentChannel.on('typingEnded', hideTypingStarted);
    tc.currentChannel.on('memberJoined', notifyMemberJoined);
    tc.currentChannel.on('memberLeft', notifyMemberLeft);
    $inputText.prop('disabled', false).focus();
  }

  function setupChannel(channel) {
    return leaveCurrentChannel()
      .then(function() {
        return initChannel(channel);
      })
      .then(function(_channel) {
        return joinChannel(_channel);
      })
      .then(initChannelEvents);
  }

  tc.loadMessages = function() {
    tc.currentChannel.getMessages(MESSAGES_HISTORY_LIMIT).then(function (messages) {
      messages.items.forEach(tc.addMessageToList);
    });
  };

  function leaveCurrentChannel() {
    if (tc.currentChannel) {
      return tc.currentChannel.leave().then(function(leftChannel) {
        console.log('left ' + leftChannel.friendlyName);
        leftChannel.removeListener('messageAdded',