Elastic & FaultTolerant GroupChat Application Messages Lib

Javascript module to manage messages between frontend and test apps and chat server. Originally design for the Elastic & FaultTolerant GroupChat Application.

Changelog

Current Version: 3.2.0 - Release 2020-10-27

• Files messages type available for browser and console

Installation

  > npm i eftgca-messages

Getting started: sample of usage:

Next example show how to use the library to send a joinRoom Message, and send/receive text messages form other users in room:

  var ChatMessagesManager = require('eftgca-messages');

  const url = 'url_of_the_websocket';
  const TEST_USERID = "UserId";
  const TEST_USERNAME = "UserName";
  const TEST_ROOMNAME = "Tests Room";

  var chatMessagesManager = new ChatMessagesManager(url);

  // suscribe to textMessage event:
  chatMessagesManager.on('textMessage',(message) => {
    console.log(message.userName + " say: " + message.text)
  });

  // suscribe to imageMessage event:
  chatMessagesManager.on('imageMessage',(imageMessage) => {
    console.log(message)
  });

  // suscribe to new users notificacion event:
  chatMessagesManager.on('newUser',(message) => {
    console.log(message.text)
  });

  // suscribe to responses event:
  chatMessagesManager.on('response',(data) => {
    console.log("Response " + data.result + " to request number "+ data.id)
  });

  // suscribe to error event:
  chatMessagesManager.on('error',(error) => {
    console.log("Error (" + error.code + "): " + error.message)
  });

  //Join User into the chat room
  chatMessagesManager.joinUser(TEST_USERID, TEST_USERNAME, TEST_ROOMNAME);

  // send messages to the room
  chatMessagesManager.sendTextMessage("Hello World!);

Constructors:

ChatMessagesManager(String url)

Create an instance with a websocket url.

Properties:

| Name | Type(Default) | Description | |-----------|:----------:|:------| | url | String | The url where the server publish the websoket | | webSocket | WebSocket | The websocket created with the url | | messageId | Int(1) | Index for the messages sent | | sessionId | uuid.v4() | Unique identifier for the connection | | userId | String | The userId | | roomName | String | The name of the room | | userName | String | The name of the user | | messages | Map() | Map to store messasges in chat| | serviceMessages | Map() | Map to store service messasges | | pendingMessages | Map() | Map to store service messasges |

Events:

The ChatMessagesManager emmit events:

| Event (String) | Data | Description | |-----------|:----------|:------| |EVENT_CONNECTED (connected)|null|Websocket connected| |EVENT_ERROR (error)|Error Message|Error ocurred| |EVENT_RESPONSE (response)|Response|The response for a previous sent message, identified by id.| |EVENT_ONCLOSE (closedConnection)|Close connection Notification|Notification for a closed connection.| |EVENT_NEW_USER (newUser)|New user Notification|Notify new user in room| |EVENT_RECONNECT (reconnect)|Reconnect notification message|Reconnection notification| |EVENT_TEXT_MESSAGE (textMessage)|Text Message|Notify new text message in room| |EVENT_IMAGE_MESSAGE (imageMessage)|Image Message|Notify new image message in room|

Messages types and specs.

• Requests and Messages sent by clients (users) must be a JSON object with these properties:

  • jsonrpc: version of JSON-RPC protocol. Always "2.0"
  • method: the name of the method
  • params: a JSON object with the method parameters
  • id: an unique identifier of the message

• Responses from server to each client message or request are also a JSON object with these properties:

  • jsonrpc: version of JSON-RPC protocol. Always "2.0"
  • result: a JSON object with the operation result. (not included if error property is defined)
  • error: a JSON object with information about an error (not included if result property is defined). This JSON object has 2 properties:
    • code: a number identifying the type of error
    • message: a string with a description about the error
  • id: an integer matching the id property of the operation call that generated this response.

• System/Server Notifications, are like Request objects without an "id" member.

  • jsonrpc: version of JSON-RPC protocol. Always "2.0"
  • method: the name of the method
  • params: a JSON object with the method parameters

For more info about JSON-RPC 2.0 Specification visit:

https://www.jsonrpc.org/specification

Available Messages:

• joinRoom: an user want to join into a chat room:

  Client Request

  {
    "jsonrpc": "2.0",
    "method": "joinRoom",
    "params": {
      "userId": "xxxxxxxxxxxxx",
      "userName": "User 1",
      "roomName": "Room 1",
    },
    "id": 1
  }

  Server Response

  {
    "jsonrpc": "2.0",
    "result": {
      "status": "Ok",
      "message": "You have joined as User 1",
      "sessionId": "8475234jh62380672306"
      },
    "id": 1
  }

  Server Error

  {
    "jsonrpc": "2.0",
    "error": {
      "code": "-32001",
      "message": "User exists (or anything else)",
      },
    "id": 1
  }

• Reconnect: an user want to reconnect due to websocket fail:

  Client Request

  {
    "jsonrpc": "2.0",
    "method": "reconnect",
    "params": {
      "userId": "xxxxxxxxxxxxx",
      "userName": "User 1",
      "roomName": "Room 1",
      "sessionId": "8475234jh62380672306",
      "lastMessageId": "5f7cb371bdb71b6e1780797b"
    },
    "id": 1
  }

  Server Response

  {
    "jsonrpc": "2.0",
    "result": {
      "status": "Ok",
      "message": "You have reconnect successfully",
      "sessionId": "8475234jh62356580672306",
      },
    "id": 1
  }

  Server Error

  {
    "jsonrpc": "2.0",
    "error": {
      "status": "-32003",
      "message": "Reconnection fail!",
      },
    "id": 1
  }

• Text message: user want to send a text message:

  Client Message

  {
    "jsonrpc": "2.0",
    "method": "textMessage",
    "params": {
      "userId": "xxxxxxxxxxxxx",
      "roomName": "Room 1",
      "userName": "User 1",
      "text": "This is the message text content",
      "ack": false,
      "uuid": "8475234jh62356580672306",
      "date": "01/01/2020 10:12:32"
    },
    "id": 2
  }

  Server Response

  {
    "jsonrpc": "2.0",
    "result": {
      "status": "OK",
      },
    "id": 2
  }

• Image message: user want to send a text message:

  Client Message

  {
    "jsonrpc": "2.0",
    "method": "textMessage",
    "params": {
      "userId": "xxxxxxxxxxxxx",
      "roomName": "Room 1",
      "userName": "User 1",
      "base64ImgString": "This is the imageBase64 string",
      "ack": false,
      "uuid": "8475234jh62356580672306",
      "date": "01/01/2020 10:12:32"
    },
    "id": 2
  }

  Server Response

  {
    "jsonrpc": "2.0",
    "result": {
      "status": "OK",
      },
    "id": 2
  }

• System/Server Message: the server send system messages to a user also to be shown on the chat

  Server Notification example

  {
    "jsonrpc": "2.0",
    "method": "notify",
    "params": {
      "type": "newUser",
      "text": "User 1 has joined the room!"
      }
  }

• Server reconnect Request: the server warn their clients that the socket is going to close, request the to reconnect to other server.

  Server Notification

  {
    "jsonrpc": "2.0",
    "method": "notify",
    "params": {
      "type": "reconnect",
      "text": "Socket is going to close, please reconnect"
    }
  }

Methods:

• joinUser(userId, userName, roomName) Send joinRomm message with userId, userName, and roomName params.
• reconnectUser(userId, userName, roomName, sessionId) Send reconnect message with userId, userName, roomName and sessionId params.
• sendTextMessage(messageText) Send text message with userId, userName, roomName and the text of the message.
• sendImageMessage(base64ImgString) Send image message with userId, userName, roomName and the base64 string of the image.
• getMessages() return all the messages (received and sent)
• getServiceMessages() return the service messages
• getPendingMessages() return all the messages that have been sent but no ack received.

License

"eftgca-messages" is licensed under Apache License.