eftgca-messages

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.

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License

"eftgca-messages" is licensed under Apache License.