{ "id": "guide/ngmodules", "title": "NgModules", "contents": "\n\n\n
\n mode_edit\n
\n\n\n
\n

NgModuleslink

\n

NgModules configure the injector and the compiler and help organize related things together.

\n

An NgModule is a class marked by the @NgModule decorator.\n@NgModule takes a metadata object that describes how to compile a component's template and how to create an injector at runtime.\nIt identifies the module's own components, directives, and pipes,\nmaking some of them public, through the exports property, so that external components can use them.\n@NgModule can also add service providers to the application dependency injectors.

\n

For an example app showcasing all the techniques that NgModules related pages\ncover, see the . For explanations on the individual techniques, visit the relevant NgModule pages under the NgModules\nsection.

\n

Angular modularitylink

\n

Modules are a great way to organize an application and extend it with capabilities from external libraries.

\n

Angular libraries are NgModules, such as FormsModule, HttpClientModule, and RouterModule.\nMany third-party libraries are available as NgModules such as\nMaterial Design,\nIonic, and\nAngularFire2.

\n

NgModules consolidate components, directives, and pipes into\ncohesive blocks of functionality, each focused on a\nfeature area, application business domain, workflow, or common collection of utilities.

\n

Modules can also add services to the application.\nSuch services might be internally developed, like something you'd develop yourself or come from outside sources, such as the Angular router and HTTP client.

\n

Modules can be loaded eagerly when the application starts or lazy loaded asynchronously by the router.

\n

NgModule metadata does the following:

\n\n

Every Angular app has at least one module, the root module.\nYou bootstrap that module to launch the application.

\n

The root module is all you need in a simple application with a few components.\nAs the app grows, you refactor the root module into feature modules\nthat represent collections of related functionality.\nYou then import these modules into the root module.

\n

The basic NgModulelink

\n

The Angular CLI generates the following basic AppModule when creating a new app.

\n\n// imports\nimport { BrowserModule } from '@angular/platform-browser';\nimport { NgModule } from '@angular/core';\n\nimport { AppComponent } from './app.component';\n\n// @NgModule decorator with its metadata\n@NgModule({\n declarations: [AppComponent],\n imports: [BrowserModule],\n providers: [],\n bootstrap: [AppComponent]\n})\nexport class AppModule {}\n\n\n\n

At the top are the import statements. The next section is where you configure the @NgModule by stating what components and directives belong to it (declarations) as well as which other modules it uses (imports). For more information on the structure of an @NgModule, be sure to read Bootstrapping.

\n

More on NgModuleslink

\n

You may also be interested in the following:

\n\n\n \n
\n\n\n" }