如何从控制器或其他组件/服务访问 websocket？

Question

我有一个 REST API，我想通过 websocket 向客户端发送事件。如何在控制器或其他组件中注入 websocket 实例？

Answer 1

类 Gateway可以注入到另一个组件中，并使用服务器实例。

@Controller()
export class AppController {
  constructor(
    private readonly appService: AppService,
    private readonly messageGateway: MessageGateway
  ) {}

  @Get()
  async getHello() {
    this.messageGateway.server.emit('messages', 'Hello from REST API');
    return this.appService.getHello();
  }
}

Answer 2

更好的解决方案是创建全局模块。然后，您可以从任何其他模块/控制器发出事件。A. 如果您尝试在其他模块中使用 Afir 方法，则会创建网关的多个实例。

注意：这只是最简单的解决方案

创建 socket.module.ts

import { Module, Global } from '@nestjs/common';
import { SocketService } from './socket.service';

@Global()
@Module({
 controllers: [],
 providers: [SocketService],
 exports: [SocketService],
})
export class SocketModule {}

socket.service.ts

import { Injectable } from '@nestjs/common';
import { Server } from 'socket.io';

@Injectable()
export class SocketService {

 public socket: Server = null;

}

app.gateway.ts见afterInit功能

import { WebSocketGateway, OnGatewayInit, OnGatewayConnection, OnGatewayDisconnect, WebSocketServer } from '@nestjs/websockets';
import { Logger } from '@nestjs/common';
import { Server, Socket } from 'socket.io';
import { SocketService } from './socket/socket.service';

@WebSocketGateway()
export class AppGateway implements OnGatewayInit, OnGatewayConnection, OnGatewayDisconnect {

  constructor(private socketService: SocketService){

  }
  @WebSocketServer() public server: Server;
  private logger: Logger = new Logger('AppGateway');


  afterInit(server: Server) {
    this.socketService.socket = server;
  }

  handleDisconnect(client: Socket) {
    this.logger.log(`Client disconnected: ${client.id}`);
  }

  handleConnection(client: Socket, ...args: any[]) {
    this.logger.log(`Client connected: ${client.id}`);
  }

}

然后导入SocketModule到 AppModule 就可以Socket service到处使用了。