nest守卫

nest守卫主要有三种方式

先执行命令：nest g res guard,创建一个名为guard的res资源文件并进入，nest g gu role,在guard资源文件里面创建一个名为role的守卫文件

方式一：全局使用守卫

在main.ts 文件中

import { NestFactory } from '@nestjs/core';
import { AppModule } from './app.module';

import * as session from 'express-session';
import * as cors from 'cors'
import { VersioningType, ValidationPipe } from '@nestjs/common';
import { Request, Response, NextFunction } from 'express'
import { NestExpressApplication } from '@nestjs/platform-express';
import { join } from 'path';

// 全局的守卫
 import { RoleGuard } from './guard/role/role.guard'

async function bootstrap() {
  const app = await NestFactory.create<NestExpressApplication>(AppModule);
  // 使用全局守卫
   app.useGlobalGuards(new RoleGuard())
  await app.listen(3000);
}
bootstrap();

方式二：单个server使用

在guard.controller.ts中

import { Controller, Get, Post, Body, Patch, Param, Delete, UseGuards, SetMetadata } from '@nestjs/common';
import { GuardService } from './guard.service';
import { CreateGuardDto } from './dto/create-guard.dto';
import { UpdateGuardDto } from './dto/update-guard.dto';
//引入守卫文件
import {RoleGuard} from './role/role.guard'

@Controller('guard')
//使用UseGuards装饰器使用守卫
@UseGuards(RoleGuard)
export class GuardController {
  constructor(private readonly guardService: GuardService) {}

  @Get()
  findAll() {
    return this.guardService.findAll();
  }
}

方式三：智能使用守卫

还是在guard.controller.ts中

import { Controller, Get, Post, Body, Patch, Param, Delete, UseGuards, SetMetadata } from '@nestjs/common';
import { GuardService } from './guard.service';
import { CreateGuardDto } from './dto/create-guard.dto';
import { UpdateGuardDto } from './dto/update-guard.dto';
//引入守卫文件
import {RoleGuard} from './role/role.guard'

@Controller('guard')
//使用UseGuards装饰器使用守卫
@UseGuards(RoleGuard)
export class GuardController {
  constructor(private readonly guardService: GuardService) {}

  @Get()
  //使用SetMetadata为此方法添加元信息，在守卫中可以获取此信息进行业务判断
  @SetMetadata('role',['admin'])
  findAll() {
    return this.guardService.findAll();
  }
}

在role/role.guard.ts中

import { CanActivate, ExecutionContext, Injectable } from '@nestjs/common';
import { Observable } from 'rxjs';
//获取路由的元信息需要用到nest核心库中的反射Reflector
import { Reflector } from '@nestjs/core';
import { Request } from 'express';


@Injectable()
export class RoleGuard implements CanActivate {
  constructor(private Reflector: Reflector) { }
  canActivate(
    context: ExecutionContext,
  ): boolean | Promise<boolean> | Observable<boolean> {

    const admin = this.Reflector.get<string[]>('role', context.getHandler())
    const req:Request = context.switchToHttp().getRequest()
    // if()
    console.log('守卫', req.query.role);
    console.log('守卫', admin);
    if(admin.includes(req.query.role as string)){
      return true
    }else{
      return false
    }
  }
}