A Module-based Angular application needs at least one module that serves as the root module. As you add features to your app, you can add them in modules. The following are frequently used Angular modules with examples of some of the things they contain:
NgModule | Import it from | Why you use it |
---|---|---|
BrowserModule |
@angular/platform-browser |
To run your application in a browser. |
CommonModule |
@angular/common |
To use NgIf and NgFor . |
FormsModule |
@angular/forms |
To build template driven forms (includes NgModel ). |
ReactiveFormsModule |
@angular/forms |
To build reactive forms. |
RouterModule |
@angular/router |
To use RouterLink , .forRoot() , and .forChild() . |
HttpClientModule |
@angular/common/http |
To communicate with a server using the HTTP protocol. |
Importing modules
When you use these Angular modules, import them in AppModule
, or your feature module as appropriate, and list them in the @NgModule
imports
array.
For example, in a new application generated by the Angular CLI with the --no-standalone
option, BrowserModule
is imported into the AppModule
.
import { BrowserModule } from '@angular/platform-browser';import { NgModule } from '@angular/core';import { AppComponent } from './app.component';@NgModule({ declarations: [ AppComponent ], imports: [ /* add modules here so Angular knows to use them */ BrowserModule, ], providers: [], bootstrap: [AppComponent]})export class AppModule { }
The imports at the top of the array are JavaScript import statements while the imports
array within @NgModule
is Angular specific.
For more information on the difference, see JavaScript Modules vs. NgModules.
BrowserModule
and CommonModule
BrowserModule
re-exports CommonModule
, which exposes many common directives such as ngIf
and ngFor
.
These directives are available to any module that imports the browser module, given the re-export.
For applications that run in the browser, import BrowserModule
in the root AppModule
because it provides services that are essential to launch and render your application in browsers.
Note: BrowserModule
's providers are for the whole application so it should only be in the root module, not in feature modules. Feature modules only need the common directives in CommonModule
; they don't need to re-install app-wide providers.