NgModule Architecture Best Practices

2.1 What is NgModule?

An NgModule is a class marked by the @NgModule decorator, which takes a metadata object that describes how to compile a component's template and how to create an injector at runtime.

2.2 NgModule Metadata

• Declarations: Components, directives, and pipes that belong to this module.
• Imports: Other modules whose exported classes are needed by component templates declared in this module.
• Exports: Subset of declarations that should be visible and usable in the component templates of other modules.
• Providers: Creators of services that this module contributes to the global collection of services; usable in all parts of the application.
• Bootstrap: The main application view, called the root component, that hosts all other app views.

3.1 Structure Your Modules

Organize your application into feature modules and shared modules.

• Feature Modules: For specific functionalities (e.g., UserModule, ProductModule).
• Shared Module: For reusable components, directives, and pipes (e.g., SharedModule).

3.2 Lazy Loading

Implement lazy loading for feature modules to improve performance and load times.

3.3 Shared Module Strategy

Use a SharedModule to encapsulate common components, directives, and pipes, and export them for other modules to use.

3.4 Avoid Circular Dependencies

Keep module dependencies tree-like to avoid circular dependencies that can lead to runtime errors.

import { NgModule } from '@angular/core';
import { CommonModule } from '@angular/common';
import { UserComponent } from './user.component';
import { UserRoutingModule } from './user-routing.module';

@NgModule({
  declarations: [UserComponent],
  imports: [
    CommonModule,
    UserRoutingModule
  ],
  exports: [UserComponent]
})
export class UserModule { }