Finally JavaScript has something useful for backend development...
let's quickly guide its basics....
npx @nestjs/cli new nestjs-example
cd nestjs-example
npm startsrc/main.ts
import { NestFactory } from '@nestjs/core';
import { AppModule } from './app.module';
async function bootstrap() {
const app = await NestFactory.create(AppModule);
await app.listen(3000);
}
bootstrap();src/app.module.ts
import { Module } from '@nestjs/common';
import { AppController } from './app.controller';
import { AppService } from './app.service';
@Module({
imports: [],
controllers: [AppController],
providers: [AppService],
})
export class AppModule {}src/app.controller.ts
import { Controller, Get } from '@nestjs/common';
import { AppService } from './app.service';
@Controller() // http:https://127.0.0.1:3000/**
export class AppController {
constructor(private readonly appService: AppService) {}
@Get() // -> GET /
getHello(): string {
return this.appService.getHello();
}
}this service will be injected in controller via constructor (see above)
src/app.service.ts
import { Injectable } from '@nestjs/common';
@Injectable()
export class AppService {
getHello(): string {
return 'Hello World!';
}
}as we can see, how we have only one endpoint: GET / which should hello:
http :3000response
HTTP/1.1 200 OK
Connection: keep-alive
Content-Length: 12
Content-Type: text/html; charset=utf-8
Date: Sun, 09 Feb 2020 13:13:44 GMT
ETag: W/"c-Lve95gjOVATpfV8EL5X4nxwjKHE"
X-Powered-By: Express
Hello World!if you familiar with ng cli (@angular/cli from Angular framework) it would be very similar!
let's implement Maksimko's module:
npx @nestjs/cli generate module maksimko
#CREATE /src/maksimko/maksimko.module.ts (85 bytes)
#UPDATE /src/app.module.ts (324 bytes)verify main module has been updated:
src/app.module.ts
import { Module } from '@nestjs/common';
import { AppController } from './app.controller';
import { AppService } from './app.service';
import { MaksimkoModule } from './maksimko/maksimko.module';
@Module({
imports: [MaksimkoModule],
controllers: [AppController],
providers: [AppService],
})
export class AppModule {}as you can see, now imports array is not empty and contains created MaksimkoModule:
src/maksimko/maksimko.module.ts
import { Module } from '@nestjs/common';
@Module({})
export class MaksimkoModule {}similarly, let's generate new controller
npx @nestjs/cli generate controller maksimko
#CREATE /src/maksimko/maksimko.controller.spec.ts (507 bytes)
#CREATE /src/maksimko/maksimko.controller.ts (105 bytes)
#UPDATE /src/maksimko/maksimko.module.ts (182 bytes)now maksimko module should be updated:
src/maksimko/maksimko.module.ts
import { Module } from '@nestjs/common';
import { MaksimkoController } from './maksimko.controller';
@Module({
controllers: [MaksimkoController]
})
export class MaksimkoModule {}and new controller created:
src/maksimko/maksimko.controller.ts
import { Controller } from '@nestjs/common';
@Controller('maksimko') // http:https://127.0.0.21:3000/maksimko/**
export class MaksimkoController {}finally let's similarly create new service:
npx @nestjs/cli generate service maksimko
#CREATE /src/maksimko/maksimko.service.spec.ts (474 bytes)
#CREATE /src/maksimko/maksimko.service.ts (92 bytes)
#UPDATE /src/maksimko/maksimko.module.ts (268 bytes)src/maksimko/maksimko.module.ts
import { Module } from '@nestjs/common';
import { MaksimkoController } from './maksimko.controller';
import { MaksimkoService } from './maksimko.service';
@Module({
controllers: [MaksimkoController],
providers: [MaksimkoService]
})
export class MaksimkoModule {}src/maksimko/maksimko.service.ts
import { Injectable } from '@nestjs/common';
@Injectable()
export class MaksimkoService {}service
import { Injectable } from '@nestjs/common';
@Injectable()
export class MaksimkoService {
wtf(what: string): string {
return `O.o ${what}?`;
}
}controller
import { Controller, Param, Post } from '@nestjs/common';
import { MaksimkoService } from './maksimko.service';
@Controller('maksimko')
export class MaksimkoController {
constructor(private maksimkoService: MaksimkoService) {}
@Post('/wtf/:what')
async wtf(@Param('what') what: string): Promise<string> {
return this.maksimkoService.wtf(what);
}
}http post :3000/maksimko/wtf/ololooutput:
HTTP/1.1 201 Created
Connection: keep-alive
Content-Length: 10
Content-Type: text/html; charset=utf-8
Date: Sun, 09 Feb 2020 15:22:17 GMT
ETag: W/"a-PbhLKehORdMno9Pz2s34zAbmS0I"
X-Powered-By: Express
O.o ololo?Nest is MIT licensed.