import { NgModule } from '@angular/core';
@NgModule({
declarations: ...,
imports: ...,
exports: ...,
providers: ...,
bootstrap: ...
})
Defines a module that contains components, directives, pipes, and providers.
class MyModule {}
List of components, directives, and pipes that belong to this module.
declarations: [MyRedComponent, MyBlueComponent, MyDatePipe]
List of modules to import into this module. Everything from the imported modules is available to declarations of this module.
imports: [BrowserModule, SomeOtherModule]
List of components, directives, and pipes visible to modules that import this module.
exports: [MyRedComponent, MyDatePipe]
List of dependency injection providers visible both to the contents of this module and to importers of this module.
providers: [MyService, { provide: ... }]
List of components to bootstrap when this module is bootstrapped.
bootstrap: [MyAppComponent]
Binds property value to the result of expression firstName.
<input [value]="firstName"> Binds attribute role to the result of expression myAriaRole.
<div [attr.role]="myAriaRole"> Binds the presence of the CSS class extra-sparkle on the element to the truthiness of the expression isDelightful.
<div [class.extra-sparkle]="isDelightful"> Binds style property width to the result of expression mySize in pixels. Units are optional.
<div [style.width.px]="mySize"> Calls method readRainbow when a click event is triggered on this button element (or its children) and passes in the event object.
<button (click)="readRainbow($event)"> Binds a property to an interpolated string, for example, "Hello Seabiscuit". Equivalent to:
<div [title]="'Hello ' + ponyName">
<div title="Hello {{ponyName}}"> Binds text content to an interpolated string, for example, "Hello Seabiscuit".
<p>Hello {{ponyName}}</p> Sets up two-way data binding. Equivalent to:
<my-cmp [title]="name" (titleChange)="name=$event">
<my-cmp [(title)]="name"> Creates a local variable movieplayer that provides access to the video element instance in data-binding and event-binding expressions in the current template.
<video #movieplayer ...>
<button (click)="movieplayer.play()">
</video> The * symbol turns the current element into an embedded template. Equivalent to:
<ng-template [myUnless]="myExpression"><p>...</p></ng-template>
<p *myUnless="myExpression">...</p> Transforms the current value of expression cardNumber via the pipe called myCardNumberFormatter.
<p>Card No.: {{cardNumber | myCardNumberFormatter}}</p> The safe navigation operator (?) means that the employer field is optional and if undefined, the rest of the expression should be ignored.
<p>Employer: {{employer?.companyName}}</p> An SVG snippet template needs an svg: prefix on its root element to disambiguate the SVG element from an HTML component.
<svg:rect x="0" y="0" width="100" height="100"/> An root element is detected as an SVG element automatically, without the prefix.
<svg>
<rect x="0" y="0" width="100" height="100"/>
</svg> import { CommonModule } from '@angular/common';Removes or recreates a portion of the DOM tree based on the showSection expression.
<section *ngIf="showSection"> Turns the li element and its contents into a template, and uses that to instantiate a view for each item in list.
<li *ngFor="let item of list"> Conditionally swaps the contents of the div by selecting one of the embedded templates based on the current value of conditionExpression.
<div [ngSwitch]="conditionExpression">
<ng-template [ngSwitchCase]="case1Exp">...</ng-template>
<ng-template ngSwitchCase="case2LiteralString">...</ng-template>
<ng-template ngSwitchDefault>...</ng-template>
</div> Binds the presence of CSS classes on the element to the truthiness of the associated map values. The right-hand expression should return {class-name: true/false} map.
<div [ngClass]="{'active': isActive, 'disabled': isDisabled}"> Allows you to assign styles to an HTML element using CSS. You can use CSS directly, as in the first example, or you can call a method from the component.
<div [ngStyle]="{'property': 'value'}">
<div [ngStyle]="dynamicStyles()"> import { FormsModule } from '@angular/forms';Provides two-way data-binding, parsing, and validation for form controls.
<input [(ngModel)]="userName"> import { Directive, ... } from '@angular/core';Declares that a class is a component and provides metadata about the component.
@Component({...})
class MyComponent() {} Declares that a class is a directive and provides metadata about the directive.
@Directive({...})
class MyDirective() {} Declares that a class is a pipe and provides metadata about the pipe.
@Pipe({...})
class MyPipe() {} Declares that a class can be injected into the constructor of another class by the dependency injector.
@Injectable()
class MyService() {} @Directive({ property1: value1, ... })Specifies a CSS selector that identifies this directive within a template. Supported selectors include element, [attribute], .class, and :not().
selector: '.cool-button:not(a)' Does not support parent-child relationship selectors.
List of dependency injection providers for this directive and its children.
providers: [MyService, { provide: ... }] @Component extends @Directive, so the @Directive configuration applies to components as well
If set, the templateUrl and styleUrl are resolved relative to the component.
moduleId: module.id List of dependency injection providers scoped to this component's view.
viewProviders: [MyService, { provide: ... }] Inline template or external template URL of the component's view.
template: 'Hello {{name}}'templateUrl: 'my-component.html' List of inline CSS styles or external stylesheet URLs for styling the component’s view.
styles: ['.primary {color: red}']styleUrls: ['my-component.css'] import { Input, ... } from '@angular/core';Declares an input property that you can update via property binding
<my-cmp [myProperty]="someExpression">@Input() myProperty; Declares an output property that fires events that you can subscribe to with an event binding
<my-cmp (myEvent)="doSomething()">@Output() myEvent = new EventEmitter(); Binds a host element property (here, the CSS class valid) to a directive/component property (isValid).
@HostBinding('class.valid') isValid; Subscribes to a host element event (click) with a directive/component method (onClick), optionally passing an argument ($event).
@HostListener('click', ['$event']) onClick(e) {...} Binds the first result of the component content query (myPredicate) to a property (myChildComponent) of the class.
@ContentChild`(myPredicate)` myChildComponent; Binds the results of the component content query (myPredicate) to a property (myChildComponents) of the class.
@ContentChildren`(myPredicate)` myChildComponents; Binds the first result of the component view query (myPredicate) to a property (myChildComponent) of the class. Not available for directives.
@ViewChild`(myPredicate)` myChildComponent; Binds the results of the component view query (myPredicate) to a property (myChildComponents) of the class. Not available for directives.
@ViewChildren`(myPredicate)` myChildComponents; Called before any other lifecycle hook. Use it to inject dependencies, but avoid any serious work here.
constructor(myService: MyService, ...) { ... } Called after every change to input properties and before processing content or child views.
ngOnChanges(changeRecord) { ... } Called after the constructor, initializing input properties, and the first call to ngOnChanges.
ngOnInit() { ... } Called every time that the input properties of a component or a directive are checked. Use it to extend change detection by performing a custom check.
ngDoCheck() { ... } Called after ngOnInit when the component's or directive's content has been initialized.
ngAfterContentInit() { ... } Called after every check of the component's or directive's content.
ngAfterContentChecked() { ... } Called after ngAfterContentInit when the component's views and child views / the view that a directive is in has been initialized.
ngAfterViewInit() { ... } Called after every check of the component's views and child views / the view that a directive is in.
ngAfterViewChecked() { ... } Called once, before the instance is destroyed.
ngOnDestroy() { ... } Sets or overrides the provider for MyService to the MyMockService class.
{ provide: MyService, useClass: MyMockService } Sets or overrides the provider for MyService to the myFactory factory function.
{ provide: MyService, useFactory: myFactory } Sets or overrides the provider for MyValue to the value 41.
{ provide: MyValue, useValue: 41 } import { Routes, RouterModule, ... } from '@angular/router';const routes: Routes = [
{ path: '', component: HomeComponent },
{ path: 'path/:routeParam', component: MyComponent },
{ path: 'staticPath', component: ... },
{ path: '', component: ... },
{ path: 'oldPath', redirectTo: '/staticPath' },
{ path: ..., component: ..., data: { message: 'Custom' } }
]);Configures routes for the application. Supports static, parameterized, redirect, and wildcard routes. Also supports custom route data and resolve.
const routing = RouterModule.forRoot(routes); Marks the location to load the component of the active route.
<router-outlet></router-outlet>
<router-outlet name="aux"></router-outlet>Creates a link to a different view based on a route instruction consisting of a route path, required and optional parameters, query parameters, and a fragment. To navigate to a root route, use the / prefix; for a child route, use the ./prefix; for a sibling or parent, use the ../ prefix.
<a routerLink="/path">
<a [routerLink]="[ '/path', routeParam ]">
<a [routerLink]="[ '/path', { matrixParam: 'value' } ]">
<a [routerLink]="[ '/path' ]" [queryParams]="{ page: 1 }">
<a [routerLink]="[ '/path' ]" fragment="anchor">The provided classes are added to the element when the routerLink becomes the current active route.
<a [routerLink]="[ '/path' ]" routerLinkActive="active"> class CanActivateGuard implements CanActivate {
canActivate(
route: ActivatedRouteSnapshot,
state: RouterStateSnapshot
): Observable<boolean>|Promise<boolean>|boolean { ... }
}An interface for defining a class that the router should call first to determine if it should activate this component. Should return a boolean or an Observable/Promise that resolves to a boolean.
{
path: ...,
canActivate: [CanActivateGuard]
}
class CanDeactivateGuard implements CanDeactivate<T> {
canDeactivate(
component: T,
route: ActivatedRouteSnapshot,
state: RouterStateSnapshot
): Observable<boolean>|Promise<boolean>|boolean { ... }
}An interface for defining a class that the router should call first to determine if it should deactivate this component after a navigation. Should return a boolean or an Observable/Promise that resolves to a boolean.
{
path: ...,
canDeactivate: [CanDeactivateGuard]
}
class CanActivateChildGuard implements CanActivateChild {
canActivateChild(
route: ActivatedRouteSnapshot,
state: RouterStateSnapshot
): Observable<boolean>|Promise<boolean>|boolean { ... }
}An interface for defining a class that the router should call first to determine if it should activate the child route. Should return a boolean or an Observable/Promise that resolves to a boolean.
{
path: ...,
canActivateChild: [CanActivateGuard],
children: ...
}
class ResolveGuard implements Resolve<T> {
resolve(
route: ActivatedRouteSnapshot,
state: RouterStateSnapshot
): Observable<any>|Promise<any>|any { ... }
}An interface for defining a class that the router should call first to resolve route data before rendering the route. Should return a value or an Observable/Promise that resolves to a value.
{
path: ...,
resolve: [ResolveGuard]
}
class CanLoadGuard implements CanLoad {
canLoad(
route: Route
): Observable<boolean>|Promise<boolean>|boolean { ... }
}An interface for defining a class that the router should call first to check if the lazy loaded module should be loaded. Should return a boolean or an Observable/Promise that resolves to a boolean.
{
path: ...,
canLoad: [CanLoadGuard],
loadChildren: ...
}