import { Controller, Get, Inject } from '@nestjs/common';

@Controller('recipes')
export class RecipesController {
  @Get()
  getRecipes() {
    return '[{"name":"Ravioli"}]';
  }
}

使用控制器进行路由

import { Module } from '@nestjs/common';
import { AppController } from './app.controller';
import { AppService } from './app.service';
// Our new controller:
import { RecipesController } from './recipes.controller'; 

@Module({
  imports: [],
  controllers: [AppController,RecipesController],
  providers: [AppService],
})
export class AppModule {}

Nest.js中的依赖注入框架让人想起Java生态系统中的Spring。仅内置依赖注入就值得考虑Nest.js，即使没有其他花里胡哨的东西。

import { Injectable } from '@nestjs/common';

@Injectable()
export class RecipesService {
  private readonly recipes = [
    {
      name: 'Ravioli',
      ingredients: ['pasta', 'cheese', 'tomato sauce'],
    },
    {
      name: 'Lasagna',
      ingredients: ['pasta', 'meat sauce', 'cheese'],
    },
    {
      name: 'Spaghetti',
      ingredients: ['pasta', 'tomato sauce'],
    },
  ];

  getRecipes() {
    return this.recipes;
  }
}

将服务添加到模块

@Module({
  imports: [],
  controllers: [AppController,RecipesController],
  providers: [AppService, RecipesService] // add the service 
})

模块是组织应用程序的好方法。它们可以充当逻辑分组机制，提供分层结构，其中最基本的模块被明确定义，其他模块依赖于它们。

import { Controller, Get, Inject } from '@nestjs/common';
import { RecipesService } from './recipes.service';

@Controller('recipes')
export class RecipesController {
  @Inject()
  private readonly recipesService: RecipesService;
  @Get()
  getRecipes() {
    return this.recipesService.getRecipes();
  }
}

从本质上讲，我们导入RecipesService类，然后为了获得对它的引用，我们在recipesService成员上使用@Inject()注释。注入系统会根据类型将其连接到RecipesService类的实例。默认情况下，注入的服务是Nest中的单例，因此所有客户端类都将获得对同一实例的引用。可以使用服务的其他“scopes”来微调它们的实例化方式。除了构造函数注入，Nest还支持基于属性的注入。

import { Injectable, CanActivate, ExecutionContext } from '@nestjs/common';

@Injectable()
export class AuthGuard implements CanActivate {
  canActivate(context: ExecutionContext): boolean {
    // Simple authentication logic
    const request = context.switchToHttp().getRequest();
    const authHeader = request.headers.authorization;
    return authHeader === 'Bearer secret-token';
  }
}

接下来，在模块中注册防护，如清单7所示。

// ...
import { AuthGuard } from './auth.guard';

@Module({
  imports: [],
  controllers: [AppController, RecipesController],
  providers: [AppService, RecipesService, AuthGuard], 
})
export class AppModule {}

现在，我们可以使用新的guard服务来保护我们的POST端点，如清单8所示。请注意新的导入。

import { Controller, Get, Inject, Post, Body, UseGuards } from '@nestjs/common';
import { RecipesService } from './recipes.service';
import { AuthGuard } from "./auth.guard";

@Controller('recipes')
export class RecipesController {
  @Inject()
  private readonly recipesService: RecipesService;
  @Get()
  getRecipes() {
    return this.recipesService.getRecipes();
  }
  @Post()
  @UseGuards(AuthGuard)
  addRecipe(@Body() recipe: any) {
    return this.recipesService.addRecipe(recipe);
  }
}

请注意，该@UserGuards注解用于将新的防护应用于addRecipe()方法，该方法也被指定为具有@Post注解的POST端点。Nest将负责为我们实例化和应用防护到端点。

addRecipe(recipe: any) {
    this.recipes.push(recipe);
    return recipe;
  }

现在，我们可以使用几个CURL请求来测试身份验证和端点，如清单10所示。

$ curl -X POST -H "Authorization: Bearer secret-token" -H "Content-Type: application/json" -d '{"name": "Carbonara", "ingredients": ["pasta", "eggs", "bacon"]}' http://localhost:3000/recipes

{"name":"Carbonara","ingredients":["pasta","eggs","bacon"]}

$ curl -X POST -H "Content-Type: application/json" -d '{"name": "Carbonara", "ingredients": ["pasta", "eggs", "bacon"]}' http://localhost:3000/recipes

{"message":"Forbidden resource","error":"Forbidden","statusCode":403}

您可以看到授权正在起作用，因为只允许持有Bearer标头的请求通过。

export class Recipe {
  constructor(public name: string, public ingredients: string[]) {}

  getName(): string {
    return this.name;
  }

  getIngredients(): string[] {
    return this.ingredients;
  }
}

最后，您可以将addRecipe()POST方法设置为强类型，Next将自动为我们填充模型对象：

import { Injectable } from '@nestjs/common';
import { Recipe } from './recipe.model';

@Injectable()
export class RecipesService {
  private readonly recipes: Recipe[] = [
    new Recipe('Ravioli', ['pasta', 'cheese', 'tomato sauce']),
    new Recipe('Lasagna', ['pasta', 'meat sauce', 'cheese']),
    new Recipe('Spaghetti', ['pasta', 'tomato sauce']),
  ];

  getRecipes(): Recipe[] {
    return this.recipes;
  }

  addRecipe(recipe: Recipe): Recipe {
    this.recipes.push(recipe);
    return recipe;
  }
}

然后，您可以将addRecipe()POST方法设置为强类型，Nest将自动为我们填充模型对象，如清单13所示。

// ...
import { Recipe } from './recipe.model';

@Controller('recipes')
export class RecipesController {
  // ...
  @Post()
  @UseGuards(AuthGuard)
  addRecipe(@Body() recipe: Recipe) {
    const newRecipe = new Recipe(recipe.name, recipe.ingredients);
    return this.recipesService.addRecipe(newRecipe);
  }
}

结论