实现一些简单的 nest 服务提供者，以此了解服务提供者的作用方式。并且自定义一个 DbModule 接入 typegoose
类注册
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| import { Module } from "@nestjs/common"
import { AppController } from "./app.controller"
import { AppService } from "./app.service"
import { MyService } from "./my/my.service"
@Module({
imports: [],
controllers: [AppController],
providers: [AppService, MyService],
})
export class AppModule {}
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使用：
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| export class AppController() {
constructor(private readonly MyService) {}
}
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完整写法，可更改提供者名称
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| import { Module } from "@nestjs/common"
import { AppController } from "./app.controller"
import { AppService } from "./app.service"
import { MyService } from "./my/my.service"
@Module({
imports: [],
controllers: [AppController],
providers: [
AppService,
{
provide: "myService",
useClass: MyService,
},
],
})
export class AppModule {}
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使用：
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| export class AppController() {
constructor(@Inject('myService') private readonly myService) {}
}
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基本数据注册
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| import { Module } from "@nestjs/common"
import { AppController } from "./app.controller"
import { AppService } from "./app.service"
@Module({
imports: [],
controllers: [AppController],
providers: [
AppService,
{
provide: "config",
useValue: { name: "wxw", author: "wxw" },
},
],
})
export class AppModule {}
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使用：
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| export class AppController {
constructor(@Inject('config') private readonly config){}
}
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动态加载模块
实现根据不同的环境创建不同的服务，首先需要获取 env 环境变量
创建 app.service.ts 和 my.service.ts
根据不同环境变量动态设置服务
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| import { Module } from "@nestjs/common"
import { AppController } from "./app.controller"
import { AppService } from "./app.service"
import { MyService } from "./my/my.service"
import path from "path"
import { config } from "dotenv"
config({ path: path.join(__dirname, "../.env") })
const appService = {
provide: "appService",
useClass: process.env.NODE_ENV === "development" ? AppService : MyService,
}
@Module({
imports: [],
controllers: [AppController],
providers: [appService],
})
export class AppModule {}
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自定义 DbModule 接入 typegoose
GitHub 仓库地址
主要代码实现
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import { DynamicModule, Module, Provider } from '@nestjs/common';
import { DbService } from './db.service';
import { getModelForClass, mongoose } from '@typegoose/typegoose';
import { ConfigService } from '@nestjs/config';
type ClassType = { new (...args: any[]): any };
@Module({})
export class DbModule {
static forRoot(envKey: string, options = {}): DynamicModule {
const providers: Provider[] = [
{
provide: 'DB_CONNECT',
inject: [ConfigService],
useFactory: (configService: ConfigService) => {
const uri = configService.get<string>(envKey, 'MONGO_URI');
return mongoose.connect(uri, options);
},
},
];
return {
module: DbModule,
providers,
exports: providers,
global: true,
};
}
static forFeature(models: ClassType[]): DynamicModule {
const providers = models.map((model) => {
return {
provide: model.name,
useFactory: () => getModelForClass(model),
} as Provider;
});
return {
module: DbModule,
providers,
exports: providers,
global: true,
};
}
}
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