@decorators/socket

Project implements decorators for Socket.IO

Installation

npm install @decorators/socket --save

API

Decorators

Class

• @Controller(namespace?: string, middleware?: Middleware[]) - registers controller for controller

Method

• @Connection(middleware?: Middleware[]) - register connection listener (io.on('connection', fn))
• @Connect(middleware?: Middleware[]) - alias of @Connection()
• @Disconnect(middleware?: Middleware[]) - register disconnect socket event (socket.on('disconnect', fn))
• @GlobalEvent(event: string) - register global event (io.on)
• @Event(event: string, middleware?: Middleware[]) - register socket event (socket.on)

Parameter

• @IO(WrapperClass?: Class) - returns server itself
• @Socket(WrapperClass?: Class) - returns socket If WrapperClass provided, returns instance of WrapperClass, passes socket or server as dependency into WrapperClass

class SocketWrapper {
  constructor(
    private ioSock: SocketIO.Server|SocketIO.Namespace|SocketIO.Socket
  ) {}
}

• @Args() - returns event arguments (excluding callback, if it exists)
• @Ack() - returns ack callback function (if it exists)

Helper Functions

• attachControllers(io: SocketIO.Server, Controller[]) - Attaches controllers to IO server

Middleware

Middleware is a class, that implements interface Middleware, like so:

class ControllerMiddleware implements Middleware {
  public use(
    io: SocketIO.Server | SocketIO.Namespace,
    socket: SocketIO.Socket,
    args: any,
    next: Function
  ) {
    console.log('ControllerMiddleware');
    next();
  }
}

To register global middleware handler create a class, that implements interface ServerMiddleware, like so:

class GlobalMiddleware implements ServerMiddleware {
  public use(
    io: SocketIO.Server | SocketIO.Namespace,
    socket: SocketIO.Socket,
    next: Function
  ) {
    console.log('GlobalMiddleware');
    next();
  }
}

Then register it by using IO_MIDDLEWARE injection token with Container from @decorators/di package, like so:

Container.provide([
  { provide: IO_MIDDLEWARE, useClass: GlobalMiddleware }
]);

Details

Middleware

The middleware order :

• Global Server Middleware (io.use(...))
• Controller based middleware (@Controller(...))
• Event based middleware (@Event(...))

Additionally to this order depends on the order how you've registered appropriate types of middleware

Quick Example:

import { listen } from 'socket.io';
import { Event, Args, attachControllers, Controller } from '@decorators/socket';

const server = listen(3000);

@Controller('/')
class MessageController {

  @Event('message')
  onMessage(@Args() message) {
    console.log(
      `Message:  ${message}`
    );
  }

}

attachControllers(server, [ MessageController ]);