Angular 2 Dynamically add components using ViewContainerRef.createComponent Rendered dynamically created component array on template html in Angular2


Example

We can create dynamic component and get the instances of component into an array and finally rendered it on template.

For example, we can can consider two widget component, ChartWidget and PatientWidget which extended the class WidgetComponent that I wanted to add in the container.

ChartWidget.ts

@Component({
selector: 'chart-widget',
templateUrl: 'chart-widget.component.html',
providers: [{provide: WidgetComponent, useExisting: forwardRef(() => ChartWidget) }]
})

export class ChartWidget extends WidgetComponent implements OnInit {
       constructor(ngEl: ElementRef, renderer: Renderer) {
    super(ngEl, renderer);
    }
    ngOnInit() {}
     close(){
      console.log('close');
    }
    refresh(){
      console.log('refresh');
    }
    ...
}

chart-widget.compoment.html (using primeng Panel)

<p-panel [style]="{'margin-bottom':'20px'}">
    <p-header>
        <div class="ui-helper-clearfix">
           <span class="ui-panel-title" style="font-size:14px;display:inline-block;margin-top:2px">Chart Widget</span>
            <div class="ui-toolbar-group-right">                
               <button pButton type="button" icon="fa-window-minimize" (click)="minimize()"</button>
              <button pButton type="button" icon="fa-refresh" (click)="refresh()"></button>
              <button pButton type="button"  icon="fa-expand" (click)="expand()" ></button>
             <button pButton type="button" (click)="close()" icon="fa-window-close"></button>
                    </div>
                </div>
    </p-header>
      some data
</p-panel>

DataWidget.ts

@Component({
    selector: 'data-widget',
    templateUrl: 'data-widget.component.html',
    providers: [{provide: WidgetComponent, useExisting: forwardRef(() =>DataWidget) }]
    })

export class DataWidget extends WidgetComponent implements OnInit {
       constructor(ngEl: ElementRef, renderer: Renderer) {
    super(ngEl, renderer);
    }
    ngOnInit() {}
    close(){
      console.log('close');
    }
    refresh(){
      console.log('refresh');
    }
    ...
}

data-widget.compoment.html (same as chart-widget using primeng Panel)

WidgetComponent.ts

@Component({
  selector: 'widget',
  template: '<ng-content></ng-content>'
})
export  class WidgetComponent{
}

we can creat dynamic component instances by selecting the pre-existing components. For example,

@Component({

    selector: 'dynamic-component',
    template: `<div #container><ng-content></ng-content></div>`

})
export class DynamicComponent {
@ViewChild('container', {read: ViewContainerRef}) container: ViewContainerRef; 

    public addComponent(ngItem: Type<WidgetComponent>): WidgetComponent {
    let factory = this.compFactoryResolver.resolveComponentFactory(ngItem);
    const ref = this.container.createComponent(factory);
    const newItem: WidgetComponent = ref.instance;              
    this._elements.push(newItem);                 
    return newItem;
  }
}

Finally we use it in app component. app.component.ts

@Component({
  selector: 'app-root',
  templateUrl: './app/app.component.html',
  styleUrls: ['./app/app.component.css'],
  entryComponents: [ChartWidget,  DataWidget], 
})

export class AppComponent {
   private elements: Array<WidgetComponent>=[];
   private WidgetClasses = {
      'ChartWidget': ChartWidget,
      'DataWidget': DataWidget        
  }
  @ViewChild(DynamicComponent) dynamicComponent:DynamicComponent;  
  
   addComponent(widget: string ): void{                         
     let ref= this.dynamicComponent.addComponent(this.WidgetClasses[widget]);    
     this.elements.push(ref); 
     console.log(this.elements);
  
     this.dynamicComponent.resetContainer();                     
  }
}

app.component.html

<button (click)="addComponent('ChartWidget')">Add ChartWidget</button>
<button (click)="addComponent('DataWidget')">Add DataWidget</button>

<dynamic-component [hidden]="true" ></dynamic-component>  

<hr>
Dynamic Components
<hr>
<widget *ngFor="let item of elements">
    <div>{{item}}</div>
   <div [innerHTML]="item._ngEl.nativeElement.innerHTML | sanitizeHtml">
   </div>
</widget>

https://plnkr.co/edit/lugU2pPsSBd3XhPHiUP1?p=preview

Some modification by @yurzui to use mouse event on the widgets

view.directive.ts

import { ViewRef, Directive, Input, ViewContainerRef } from '@angular/core';

@Directive({
    selector: '[view]'
})
export class ViewDirective {
  constructor(private vcRef: ViewContainerRef) {}

  @Input()
  set view(view: ViewRef) {
    this.vcRef.clear();
    this.vcRef.insert(view);
  }

  ngOnDestroy() {
    this.vcRef.clear()
  }
}

app.component.ts

private elements: Array<{ view: ViewRef, component: WidgetComponent}> = [];

...
addComponent(widget: string ): void{
  let component = this.dynamicComponent.addComponent(this.WidgetClasses[widget]);
  let view: ViewRef = this.dynamicComponent.container.detach(0);
  this.elements.push({view,component});

  this.dynamicComponent.resetContainer();
}

app.component.html

<widget *ngFor="let item of elements">
  <ng-container *view="item.view"></ng-container>
</widget>

https://plnkr.co/edit/JHpIHR43SvJd0OxJVMfV?p=preview