WebSocket Chat

This is a sample (and simple) websocket powered chat. It requires Node.js and PHP on the server side.

Installation is really easy and only requires the ws package for Node.js. One may install it using npm.

npm install ws

Check the settings.json file in order to make changes to host, port as well as SSL settings.

The file wschat.conf is a sample upstart script for Ubuntu.

The chat protocol

The chat protocol works with JSON messages. Sample data will be used to explain the protocol details. Notice that messages of type list_rooms, for example, can be used on both directions (SERVER -> CLIENT or CLIENT -> SERVER). So, despite they have the same name, they have different meanings.

• welcome: The SERVER sends the welcome message once a new CLIENT connects. The message contains the ID and a temporary name "User X" that can be changed anytime.

  {
    "type": "welcome",
    "user": {
      "id": 3,
      "name": "User 3"
    }
  }

• list_rooms: The CLIENT asks the SERVER to list all avaialble rooms for chat.

  {
    "type": "list_rooms"
  }

  Answer: The SERVER answers the client with the list of available rooms.

  {
    "type": "list_rooms",
    "rooms": {
      "1": {
        "id": 1,
        "title": "Room 1",
        "users": {
          "2": {
            "id": 2,
            "name": "Some user"
          }
        }
      },
      "2": {
        "id": 2,
        "title": "Room 2",
        "users": {}
      },
      "3": {
        "id": 3,
        "title": "Room 3",
        "users": {}
      }
    }
  }

• enter_room: The CLIENT asks the SERVER to enter in a specific room, via roomId.

  {
    "type": "enter_room",
    "roomId": "1"
  }

  Answer: The SERVER broadcasts the answer to every participant of the room. So they can be notified about the new user in the room.

  {
    "type": "enter_room",
    "user": {
      "id": 5,
      "name": "User 5"
    }
  }

• text: The CLIENT sends a text message to the chat.

  {
    "type": "text",
    "text": "some message"
  }

  Answer: The SERVER broadcasts the text to every participant of the room identifying the sender of the text message.

  {
    "type": "text",
    "text": "some message",
    "from": {
      "id": 4,
      "name": "User 4"
    }
  }

• gif: The CLIENT sends a gif message to the chat, identified by a gifId.

  {
    "type": "gif",
    "gifId": 3
  }

  Answer: The SERVER broadcasts the gif to every participant of the room identifying the sender of the gif.

  {
    "type": "gif",
    "gifId": 3,
    "from": {
      "id": 4,
      "name": "User 4"
    }
  }

• leave_room: The CLIENT sends this message when he/she wants to leave the room.

  {
    "type": "leave_room"
  }

  Answer: The SERVER broadcasts it to all participants of the room.

  {
    "type": "leave_room",
    "user": {
      "id": 2,
      "name": "User 2"
    }
  }

• create_room: The CLIENT sends this message to the SERVER to create a new room.

  {
    "type": "create_room",
    "title": "some new room"
  }

  Answer: The SERVER will broadcast list_rooms to all clients.

• change_name: The CLIENT can change his/her name.

  {
    "type": "change_name",
    "name": "my new name"
  }

  Answer: The SERVER will broadcast change_name to all participants of the room only if the sender of the message is in room. Otherwise, nothing happens.

  {
    "type": "change_name",
    "oldName": "My old name",
    "newName": "My new name"
  }