Cheat Sheet
Bootstrapping |
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platformBrowserDynamic().bootstrapModule(AppModule); |
Bootstraps the app, using the root component from the specified |
NgModules |
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@NgModule({ declarations: ..., imports: ..., exports: ..., providers: ..., bootstrap: ...})class MyModule {} |
Defines a module that contains components, directives, pipes, and providers. |
declarations: [MyRedComponent, MyBlueComponent, MyDatePipe] |
List of components, directives, and pipes that belong to this module. |
imports: [BrowserModule, SomeOtherModule] |
List of modules to import into this module. Everything from the imported modules is available to |
exports: [MyRedComponent, MyDatePipe] |
List of components, directives, and pipes visible to modules that import this module. |
providers: [MyService, { provide: ... }] |
List of dependency injection providers visible both to the contents of this module and to importers of this module. |
entryComponents: [SomeComponent, OtherComponent] | List of components not referenced in any reachable template, for example dynamically created from code. |
bootstrap: [MyAppComponent] |
List of components to bootstrap when this module is bootstrapped. |
Template syntax | |
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<input [value]="firstName"> |
Binds property |
<div [attr.role]="myAriaRole"> |
Binds attribute |
<div [class.extra-sparkle]="isDelightful"> |
Binds the presence of the CSS class |
<div [style.width.px]="mySize"> |
Binds style property |
<button (click)="readRainbow($event)"> |
Calls method |
<div title="Hello {{ponyName}}"> |
Binds a property to an interpolated string, for example, "Hello Seabiscuit". Equivalent to: |
<p>Hello {{ponyName}}</p> |
Binds text content to an interpolated string, for example, "Hello Seabiscuit". |
<my-cmp [(title)]="name"> |
Sets up two-way data binding. Equivalent to: |
<video #movieplayer ...> <button (click)="movieplayer.play()"></video> |
Creates a local variable |
<p *myUnless="myExpression">...</p> |
The |
<p>Card No.: {{cardNumber | myCardNumberFormatter}}</p> |
Transforms the current value of expression |
<p>Employer: {{employer?.companyName}}</p> |
The safe navigation operator ( |
<svg:rect x="0" y="0" width="100" height="100"/> |
An SVG snippet template needs an |
<svg> <rect x="0" y="0" width="100" height="100"/></svg> |
An |
Built-in directives |
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<section *ngIf="showSection"> |
Removes or recreates a portion of the DOM tree based on the |
<li *ngFor="let item of list"> |
Turns the li element and its contents into a template, and uses that to instantiate a view for each item in list. |
<div [ngSwitch]="conditionExpression"> <ng-template [ngSwitchCase]="case1Exp">...</ng-template> <ng-template ngSwitchCase="case2LiteralString">...</ng-template> <ng-template ngSwitchDefault>...</ng-template></div> |
Conditionally swaps the contents of the div by selecting one of the embedded templates based on the current value of |
<div [ngClass]="{'active': isActive, 'disabled': isDisabled}"> |
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 [ngStyle]="{'property': 'value'}"> <div [ngStyle]="dynamicStyles()">
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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. |
Forms |
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<input [(ngModel)]="userName"> |
Provides two-way data-binding, parsing, and validation for form controls. |
Class decorators |
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@Component({...})class MyComponent() {} |
Declares that a class is a component and provides metadata about the component. |
@Directive({...})class MyDirective() {} |
Declares that a class is a directive and provides metadata about the directive. |
@Pipe({...})class MyPipe() {} |
Declares that a class is a pipe and provides metadata about the pipe. |
@Injectable()class MyService() {} |
Declares that a class has dependencies that should be injected into the constructor when the dependency injector is creating an instance of this class. |
Directive configuration |
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selector: '.cool-button:not(a)' |
Specifies a CSS selector that identifies this directive within a template. Supported selectors include Does not support parent-child relationship selectors. |
providers: [MyService, { provide: ... }] |
List of dependency injection providers for this directive and its children. |
Component configuration |
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moduleId: module.id |
If set, the |
viewProviders: [MyService, { provide: ... }] |
List of dependency injection providers scoped to this component's view. |
template: 'Hello {{name}}'templateUrl: 'my-component.html' |
Inline template or external template URL of the component's view. |
styles: ['.primary {color: red}']styleUrls: ['my-component.css'] |
List of inline CSS styles or external stylesheet URLs for styling the component’s view. |
Class field decorators for directives and components |
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@Input() myProperty; |
Declares an input property that you can update via property binding (example: |
@Output() myEvent = new EventEmitter(); |
Declares an output property that fires events that you can subscribe to with an event binding (example: |
@HostBinding('class.valid') isValid; |
Binds a host element property (here, the CSS class |
@HostListener('click', ['$event']) onClick(e) {...} |
Subscribes to a host element event ( |
@ContentChild(myPredicate) myChildComponent; |
Binds the first result of the component content query ( |
@ContentChildren(myPredicate) myChildComponents; |
Binds the results of the component content query ( |
@ViewChild(myPredicate) myChildComponent; |
Binds the first result of the component view query ( |
@ViewChildren(myPredicate) myChildComponents; |
Binds the results of the component view query ( |
Directive and component change detection and lifecycle hooks |
(implemented as class methods) |
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constructor(myService: MyService, ...) { ... } |
Called before any other lifecycle hook. Use it to inject dependencies, but avoid any serious work here. |
ngOnChanges(changeRecord) { ... } |
Called after every change to input properties and before processing content or child views. |
ngOnInit() { ... } |
Called after the constructor, initializing input properties, and the first call to |
ngDoCheck() { ... } |
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. |
ngAfterContentInit() { ... } |
Called after |
ngAfterContentChecked() { ... } |
Called after every check of the component's or directive's content. |
ngAfterViewInit() { ... } |
Called after |
ngAfterViewChecked() { ... } |
Called after every check of the component's views and child views / the view that a directive is in. |
ngOnDestroy() { ... } |
Called once, before the instance is destroyed. |
Dependency injection configuration | |
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{ provide: MyService, useClass: MyMockService } |
Sets or overrides the provider for |
{ provide: MyService, useFactory: myFactory } |
Sets or overrides the provider for |
{ provide: MyValue, useValue: 41 } |
Sets or overrides the provider for |
Routing and navigation |
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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' } }]);const routing = RouterModule.forRoot(routes); |
Configures routes for the application. Supports static, parameterized, redirect, and wildcard routes. Also supports custom route data and resolve. |
<router-outlet></router-outlet><router-outlet name="aux"></router-outlet> |
Marks the location to load the component of the active route. |
<a routerLink="/path"><a [routerLink]="[ '/path', routeParam ]"><a [routerLink]="[ '/path', { matrixParam: 'value' } ]"><a [routerLink]="[ '/path' ]" [queryParams]="{ page: 1 }"><a [routerLink]="[ '/path' ]" fragment="anchor"> |
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 |
<a [routerLink]="[ '/path' ]" routerLinkActive="active"> |
The provided classes are added to the element when the |
class CanActivateGuard implements CanActivate { canActivate( route: ActivatedRouteSnapshot, state: RouterStateSnapshot ): Observable<boolean>|Promise<boolean>|boolean { ... }}{ path: ..., canActivate: [CanActivateGuard] } |
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. |
class CanDeactivateGuard implements CanDeactivate<T> { canDeactivate( component: T, route: ActivatedRouteSnapshot, state: RouterStateSnapshot ): Observable<boolean>|Promise<boolean>|boolean { ... }}{ path: ..., canDeactivate: [CanDeactivateGuard] } |
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. |
class CanActivateChildGuard implements CanActivateChild { canActivateChild( route: ActivatedRouteSnapshot, state: RouterStateSnapshot ): Observable<boolean>|Promise<boolean>|boolean { ... }}{ path: ..., canActivateChild: [CanActivateGuard], children: ... } |
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. |
class ResolveGuard implements Resolve<T> { resolve( route: ActivatedRouteSnapshot, state: RouterStateSnapshot ): Observable<any>|Promise<any>|any { ... }}{ path: ..., resolve: [ResolveGuard] } |
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. |
class CanLoadGuard implements CanLoad { canLoad( route: Route ): Observable<boolean>|Promise<boolean>|boolean { ... }}{ path: ..., canLoad: [CanLoadGuard], loadChildren: ... } |
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. |
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Licensed under the Creative Commons Attribution License 4.0.
https://v7.angular.io/guide/cheatsheet