看遍了koa,express以及其衍生框架之后，发现NodeJs的Web开发框架似乎跳不出一个固定的模式，这个问题也困扰着PHP，那就是能不能通过注解来简化开发？
实际上PHP是有“注解”的，不过是通过反射读取注释实现，非常低级。
今天要讲的是一个划时代的NodeJs Web框架——nestjs

示例代码

在介绍nestjs之前，先让大家看一看nestjs的示例代码。

1. HTTP接口

@Controller('socket')
@UseGuards(AdminGuard)
export class SocketController {private logger: Logger = new Logger(SocketController.name);constructor(private readonly gateway: SocketGateway,private readonly salesmanService: SalesmanService,private readonly hashidService: HashidService) {}@Post('interaction')async send(@Query('salesman_id') salesmanId: number, @Query('user_id') userId: number, @Body('content') content: string) {if (!salesmanId || !userId || !content) {throw new BadRequestException('Bad Request');}const salesman = await this.salesmanService.findById(salesmanId);if (!salesman) {throw new NotFoundException('销售不存在');}const roomId = this.salesmanService.makeSyncRoomKey(salesman);this.gateway.namespace.to(roomId).emit(SocketEvent.OnInteraction, { user_id: this.hashidService.encode(userId), content });return { errmsg: 'ok', errcode: 0 };}
}

1. Socket.IO

@UseFilters(new WsExceptionFilter())
@WebSocketGateway({ namespace: 'socket', adapter: adapter(appConfig.redis) })
export class SocketGateway implements OnGatewayInit<SocketIO.Namespace>, OnGatewayConnection<SocketIO.Socket> {private logger: Logger = new Logger(SocketGateway.name);@WebSocketServer() public readonly namespace: SocketIO.Namespace;public adapter: adapter.RedisAdapter;constructor(private readonly salesmanService: SalesmanService,private readonly corporationService: CorporationService,private readonly hashidService: HashidService,private readonly userService: UserService,private readonly roomService: RoomService,private readonly messageService: MessageService,private readonly readService: ReadService,private readonly memberService: MemberService,) {}afterInit(server: SocketIO.Namespace): any {this.adapter = server.adapter as adapter.RedisAdapter;this.logger.log(`initialized ${server.name}`);}/*** 进入聊天室* @param {SocketIO.Socket} client* @returns {any}*/async handleConnection(client: SocketIO.Socket): Promise<any> {const { user_id, token, corporation_id, sign } = qs.parse(url.parse(client.request.url).query) as {[name: string]: string;};if (!user_id && !token && !corporation_id && !sign) {client.disconnect(true);return;}const realUserId = this.hashidService.decode(user_id);await promisify(client.join.bind(client))(this.roomService.makePersonalRoomId(realUserId)),client.emit(SocketEvent.Ready);}@SubscribeMessage(SocketEvent.Join)handleJoin(client: SocketIO.Socket, data: any) {if (JoinType.Chat === data.type) {return this.handleJoinChat(client, data);}if (JoinType.Sync === data.type) {return this.handleJoinSync(client, data);}client.disconnect(true);}@SubscribeMessage(SocketEvent.Leave)async handleLeave(client: SocketIO.Socket, data: any) {const { user_id, token, corporation_id, sign } = qs.parse(url.parse(client.request.url).query) as {[name: string]: string;};if (JoinType.Chat === data.type) {await promisify(client.leave.bind(client))(data.room_id);return { event: SocketEvent.Leave, data };}const isPersonal = user_id && token;const roomId = isPersonal? await this.salesmanService.getRoomId(user_id, token): await this.corporationService.getRoomId(corporation_id, sign);if (roomId) {await promisify(client.leave).bind(client)(roomId);}return { event: SocketEvent.Leave, data };}
// ...

写法是不是很像Java?或者说是Angular4?

介绍

实际上nestjs的架构源自于java的spring框架，而代码组织则借鉴与Angular4的Module。

nestjs模块架构图

开始开发

1. yarn global add @nestjs/cli
2. nest new projectName
3. cd projectName && yarn start

写在最后

由于篇幅关系，nestjs的详细文档可以前往官网查看，本文只是做个框架介绍，开启新世界的大门。