Angular's Feature Module ( Feature Module )

Project structure

1. Create a feature module, and the components and services it contains.

of g module art
of g component art / music
of g component art / dance
of g service art /performance

 

Two feature modules

art.module.ts

import { NgModule } from '@angular/core';
import { CommonModule } from '@angular/common';
import { MusicComponent } from './music/music.component';
import { DanceComponent } from './dance/dance.component';
import { PerformanceService } from './performance.service';

@NgModule ({
  imports: [
    CommonModule
  ],
  // Associate feature modules with components: add declarable objects (components, directives, and pipes) specific to this module 
  declarations: [MusicComponent, DanceComponent],
   // Export components: After importing a feature module, you can use the The component template 
  exports: [
    MusicComponent,
    DanceComponent
  ],
  providers: [
    PerformanceService
  ]
})
export class ArtModule { }

 

three components

music.component.ts

import { Component, OnInit, Input } from '@angular/core';

@Component({
  selector: 'app-music',
  templateUrl: './music.component.html',
  styleUrls: ['./music.component.css']
})
export class MusicComponent implements OnInit {

  @Input()
  name: string;

  constructor() { }

  by OnInit () {
  }

}

 

music.component.html

<p>
  music works!{{name}}
</p>

 

dance.component.ts

import { Component, OnInit, Input } from '@angular/core';

@Component({
  selector: 'app-dance',
  templateUrl: './dance.component.html',
  styleUrls: ['./dance.component.css']
})
export class DanceComponent implements OnInit {

  @Input()
  name: string;

  constructor() { }

  by OnInit () {
  }

}

 

dance.component.html

<p>
  dance works!{{name}}
</p>

 

Four services

performance.service.ts

import { Injectable } from '@angular/core';

@Injectable()
export class PerformanceService {

  constructor() { }

  perform(): string[] {
    return [ 'singing' , 'dancing' ];
  }
}

 

Five import feature modules

app.module.ts

import { BrowserModule } from '@angular/platform-browser';
import { NgModule } from '@angular/core';


import { AppComponent } from './app.component';
import { ArtModule } from './art/art.module';


@NgModule ({
  declarations: [
    AppComponent
  ],
  imports: [
    BrowserModule,
    ArtModule
  ],
  providers: [],
  bootstrap: [AppComponent]
})
export class AppModule { }

 

Six components and services using feature modules

app.component.ts

import { Component } from '@angular/core';
import { PerformanceService } from './art/performance.service';

@Component({
  selector: 'app-root',
  templateUrl: './app.component.html',
  styleUrls: ['./app.component.css']
})
export class AppComponent {
  
  constructor(public performance: PerformanceService) {

  }
  perform() {
    console.log(this.performance.perform());
  }
}

 

app.component.html

<p>
  app works!
</ p > 
<!-- Both one-way bindings work --> 
< app-music [name] ="'Adelina by the Water'" ></ app-music > 
< app-dance name = "Tap Dance" ></ app-dance > 
< button type = "button" (click) = "perform();" > show </ button >

 

Seven running effects