Angular 2 - Architecture

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The following screenshot shows the anatomy of an Angular 2 application. Each application consists of Components. Each component is a logical boundary of functionality for the application. You need to have layered services, which are used to share the functionality across components.

Following is the anatomy of a Component. A component consists of −

• Class − This is like a C++ or Java class which consists of properties and methods.

• Metadata − This is used to decorate the class and extend the functionality of the class.

• Template − This is used to define the HTML view which is displayed in the application.

Following is an example of a component.

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

@Component ({ 
   selector: 'my-app', 
   templateUrl: 'app/app.component.html' 
}) 

export class AppComponent { 
   appTitle: string = 'Welcome';
} 

Each application is made up of modules. Each Angular 2 application needs to have one Angular Root Module. Each Angular Root module can then have multiple components to separate the functionality.

Following is an example of a root module.

import { NgModule }      from '@angular/core'; 
import { BrowserModule } from '@angular/platform-browser'; 
import { AppComponent }  from './app.component';  

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

Each application is made up of feature modules where each module has a separate feature of the application. Each Angular feature module can then have multiple components to separate the functionality.