[Nest.js] 2 - Module

Constent
1. Module?
2. Module structure
3. Create Module

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1. Module? 

- Module is a class made by @Module() decorator

- It provides metadata to Nest to build application structure

- Each application has one or more modules, and root module is defined when application created

main.ts

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

async function bootstrap() {
  const app = await NestFactory.create(AppModule); // AppModule is ROOT
  await app.listen(3000);
}
bootstrap();

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2. Module Structure

- Module should be a set of related functions(such as UserModule, OrderModule, or ChatModule...)

- Classes for the related function are in a module(such as UserController, UserService, UserEntity... in  UserModule)

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3. Create Module

- CLI

$ nest g module boards // boards module create

project navigator

- it automatically register in root module where is app.module.ts now.

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4. Register Module

- new module should register in a root module

* deleted unneccessary defualt files, remains only main.ts and app.module.ts

app.module.ts