[Angular 2] Set Properties on Dynamically Created Angular 2 Components

时间:2021-11-09 15:51:16

When you generate Angular 2 components, you’re still able to access the component instance to set properties and invoke methods from the component class.

import {Component, ViewChild, ViewContainerRef, ComponentFactoryResolver, Input} from '@angular/core';
import {SimpleService} from "../../serivces/simple.service";
import {WidgetThree} from "../widgets/widget-three.component"; @Component({
moduleId: module.id,
selector: 'home',
templateUrl: 'home.component.html'
})
export class HomeComponent { @ViewChild('container', {
read: ViewContainerRef
}) container; constructor(private resolver: ComponentFactoryResolver, private simpleService: SimpleService) {
} ngAfterContentInit(){
const WidgetFactory = this.resolver.resolveComponentFactory(WidgetThree);
this.container.createComponent(WidgetFactory);
this.container.createComponent(WidgetFactory);
this.container.createComponent(WidgetFactory);
this.container.createComponent(WidgetFactory);
const comRef = this.container.createComponent(WidgetFactory); // return a componentRef
comRef.instance.message = "I am last"; // using componentRef's instance prop to access the component prop
comRef.instance.renderer.setElementStyle(
comRef.instance.input.nativeElement,
'color',
'red'
)
} }

widget-three.ts:

import {Component, OnInit, ViewChild, Renderer, ElementRef, Input} from '@angular/core';

@Component({
moduleId: module.id,
selector: 'widget-three',
template: `<input type="text" #inputRef [value]="message"/>`
})
export class WidgetThree { @ViewChild('inputRef') input;
@Input() message = "Default Value"; constructor(private renderer: Renderer) {
} ngAfterViewInit(){
this.renderer.invokeElementMethod(
this.input.nativeElement,
'focus',
[]
);
}
}

So each time, when we call 'createComponent' method, it returns a ComponentRef instance. See https://angular.io/docs/ts/latest/api/core/index/ViewContainerRef-class.html

We can use the instance to access the generated component's props, such as 'Renderer' or Input (message). Here we change the message value.

 comRef.instance.message = "I am last";

And change the style thought Renderer:

        comRef.instance.renderer.setElementStyle(
comRef.instance.input.nativeElement,
'color',
'red'
)