@nexjs-ws

Introduction

We use websocket as an Inter program or module communication protocol. I develop a custom protocol over Websocket that implement this 2 Patterns

Request/Response Pattern
Publish/Subscribe Pattern

We can response to almost any problems in a effective way with a combination of this 2 patterns:

Synchronized calls
Notifications by Events

the idea

Separate in server the Functionality (Contract) from the call protocol and transport (Rest API, Websocket TCP IP, HTTP, ...) and create or update typed clients automatically. the main goals are

Alway typed (Client and Server)
Never implement a client
Any update generate errors in code
Separate functions (contracts) from transports and protocols. You van bind multiples protocols and transports on one server without code duplication.
Realtime Applications: the combination of Publish/Subscribe and Rest is required for an easy implementation.
Really simplified server code.
Authentication separated from functionality

Code overview

Only Implements the server
automatic client generation (ts or c#)

server

// ----------------------------------------------------------------------------
// [ Functionalities ]
class AContract {

  // [ decorators ]
  @Hub({ service: 'aContract', ...}) // Publish/Subscribe Protocol over websocket
  onUpdate = new HubEvent();         // Emitter custom class - only to unificate 
                                     // event system

  // [ decorators ]
  @Rest({ service: 'aContract',...}) // Request/Response Protocol over websocket
  methodA(): Promise<void>{
    // anything                      // Can return anything
  }  
}

// ----------------------------------------------------------------------------
// main.ts

const ioServer = ... // socket.io initialization 

// [ the binding ]
const wss = new WSServer<User, Token>();  // create Websocket protocols
wss.register(new AContract ());           // register class 
wss.init(new SocketIOServer(ioServer));   // initialize with a socket.io server

cli (typed api client creation)

// ----------------------------------------------------------------------------
// in command line (create api client)
npm install @nexjs/cli -g
nexjs ts ws up-client -s ./[server-folder] -o ./[client-folder]/[api-folder]

client

// ----------------------------------------------------------------------------
// in client (after automatic generation)
const wsapi = new WSApi<User, Token>(new SocketIOClient()); // create client

// [Publish/Subscribe] protocol
// 1. register event Handler
wsapi.aContract.onUpdate.on(() =>
  console.log(`onUpdate`) // 
);
// 2. Subscribe to event
await wsapi.baseContract.onUpdate.sub();

// [Request/Response]  protocol 
await wsapi.baseContract.methodA();

//That's all !!!