Add angular component to tab

[admin]

how can i add an angular comonent dynamically as a tab page

[admin]

Hello helkatz,
We prepared a help topic that describes how to add an Angular component dynamically to a tab item. You can find it here: https://www.htmlelements.com/docs/angular-dynamic-component-loading/. We hope it is helpful to you.
Best regards,
Dimitar
Smart HTML Elements Team
https://www.htmlelements.com

[dilbert]

The mentioned help topic does work, however, as of Angular 15 the ComponentFactoryResolver is deprecated.  Is there a newer method?  I’m hesitant to base new software off of something that could be removed in the future.

[admin]

As we currently do not have this updated on our website, you may look at https://stackoverflow.com/questions/70946038/replace-deprecated-angular-componentfactoryresolver-componentfactory.

[dilbert]

With that method I need the ​ViewContainerRef for the containing component which I can easily do by adding a custom anchor to smart-tab-item to expose it.  However, we a new tab is added via the built in add button, the new smart-tab-item doesn’t have this tag.  It also doesn’t get added to a @ViewChildren QueryList. (i.e. @ViewChildren(TabItemComponent) items: QueryList<TabItemComponent>).  The items list is never updated with any smart-tab-items created using the add tab button.

Is there an easy way to get ViewContainerRef for the dynamically added smart items?

[admin]

Hi dilbert,

Could you post an example about this?

Regards,
Peter

[dilbert]

Here is an example that illustrates the issue. The first 2 tabs get a dynamic component, but those that are added later do not.

Template:

<div>Num of smart-tab-items: {{smartItems.length}}</div>
<div>Num of tabs: {{numTabs}}</div>
<smart-tabs #tabs id="tabs" class="demoTabsShort" [closeButtons]="true" [closeButtonMode]="'selected'"
[addNewTab]="true" (addNewTabClick)="onAddNewTabClick($event)" [reorder]="true">
    <smart-tab-item [label]="'Tab_1'"><ng-container app-view-ref></ng-container></smart-tab-item>
    <smart-tab-item [label]="'Tab_2'"><ng-container app-view-ref></ng-container></smart-tab-item>
</smart-tabs>

Main component:

import { Component, AfterViewInit, ViewChildren, QueryList, ViewChild } from '@angular/core';
import { TabItemComponent, TabsComponent } from 'smart-webcomponents-angular/tabs';
import { ThingComponent } from './thing.component';
import { ViewRefAnchorDirective } from './view-ref-anchor.directive';

@Component({
  selector: 'app-root',
  templateUrl: './app.component.html',
  styleUrls: ['./app.component.css']
})
export class AppComponent implements AfterViewInit {

  // I am expecting this list to be updated when new tabs are added.
  @ViewChildren(TabItemComponent) smartItems = new QueryList();

  @ViewChildren(ViewRefAnchorDirective) anchors = new QueryList();

  @ViewChild('tabs', {read: TabsComponent, static: false}) tabs!: TabsComponent;

  numTabs = 0;

  ngAfterViewInit(): void {
    this.tabs.getTabs().then(tabs => {
      this.numTabs = tabs.length;
    });

    this.anchors.forEach(tab => this.loadComponent(tab));
  }

  onAddNewTabClick(event: Event) {
    this.tabs.getTabs().then(tabs => {
      this.numTabs = tabs.length;

      // At this point this.smartItems only has the original 2 smart-tab-items
      // It would appear the new tabs are not known to Angular since they aren't
      // added to the QueryList.

      // this.anchors also only has the original 2.  this.anchors.last references
      // the second tab.  Additional tabs do not get a new component.
      this.loadComponent(this.anchors.last);
    });
  }

  loadComponent(viewRefAnchor: ViewRefAnchorDirective) {
    viewRefAnchor.viewContainerRef.clear();
    viewRefAnchor.viewContainerRef.createComponent(ThingComponent);
  }
}

Anchor directive:

import { Directive, ViewContainerRef } from "@angular/core";
/**
 * An directive to expose the ViewContainerRef to allow components to be dynamically
 * created and added.
 */
@Directive({
  selector: '[app-view-ref]'
})
export class ViewRefAnchorDirective {

  constructor(public viewContainerRef: ViewContainerRef) { }

}

Dynamic component:

import { Component, OnInit } from '@angular/core';

@Component({
  selector: 'app-thing',
  template: '<p>test-component works!</p>'
})
export class ThingComponent implements OnInit {

  constructor() { }

  ngOnInit(): void {
  }

}

[dilbert]

The other thing I’ve tried is to use an ngFor to define the tabs:

<smart-tabs #tabs id="tabs" class="demoTabsShort" [closeButtons]="true" [closeButtonMode]="'selected'"
[addNewTab]="true" (addNewTabClick)="onAddNewTabClick($event)" [reorder]="true">
    <smart-tab-item *ngFor="let tab of tabNames" [label]="tab"><app-thing></app-thing></smart-tab-item>
</smart-tabs>

Where tabNames is just a list of strings.

When a new tab is added (by appending a new string to the tabNames array), the content of the new tab is the new component. However, the label is not updated and there is an error in the console:

core.mjs:8506 ERROR TypeError: Cannot read properties of undefined (reading 'firstElementChild')
    at BaseElement._updateTabLabel (smart.tabs.js:34:65344)
    at BaseElement.propertyChangedHandler (smart.tabs.js:34:1110)
    at t.updateProperty (smart.button.js:34:75016)
    at BaseElement.set [as label] (smart.button.js:34:76150)
    at set label [as label] (smart-webcomponents-…ular-tabs.js:771:54)
    at Object.ngOnChangesSetInput [as setInput] (core.mjs:1586:26)
    at setInputsForProperty (core.mjs:11738:17)
    at elementPropertyInternal (core.mjs:10874:9)
    at Module.ɵɵproperty (core.mjs:13637:9)
    at AppComponent_smart_tab_item_6_Template (app.component.html:5:50)

• This reply was modified 2 years, 3 months ago by dilbert.

[admin]

Hi,

The thing is that the add new tab button adds an empty tab. It does not add a new tab with the template structure you added in the template i.e the new tab does not have ng-container in it. For that purpose we can use ng-template. Please, take a look at the updated code below

import { Component, AfterViewInit, ViewChildren, QueryList, ViewChild, ComponentRef, ChangeDetectorRef, ViewContainerRef } from '@angular/core';
import { TabItem, TabItemComponent, TabsComponent } from 'smart-webcomponents-angular/tabs';
import { ThingComponent } from './thing.component';
import { ViewRefAnchorDirective } from './view-ref-anchor.directive';

@Component({
  selector: 'app-root',
  templateUrl: './app.component.html',
  styleUrls: ['./app.component.css']
})
export class AppComponent implements AfterViewInit {

  // I am expecting this list to be updated when new tabs are added.
  smartItems: TabItem[] = [];

  @ViewChildren(ViewRefAnchorDirective) anchors = new QueryList();

  @ViewChild('tabs', {read: TabsComponent, static: false}) tabs!: TabsComponent;
  @ViewChild('dynamic', { read: ViewContainerRef })

  viewRef!: ViewContainerRef;

  numTabs = 0;

  ngAfterViewInit(): void {
    this.tabs.getTabs().then(tabs => {
      this.numTabs = tabs.length;
    });

    this.anchors.forEach(tab => this.loadComponent(tab as any));
 	this.smartItems = Array.from(document.querySelectorAll('smart-tab-item'));
	 }

  onAddNewTabClick(event: Event) {
    this.tabs.getTabs().then(tabs => {
      this.numTabs = tabs.length;

      	// create a new dynamic component.
		const container = document.createElement('div');
		const componentRef: ComponentRef<ThingComponent> =  this.viewRef.createComponent(ThingComponent);
	
		// dynamically add the component to a new container host element.
		container.appendChild(componentRef.location.nativeElement);
		// update tabs.
		this.tabs.update(tabs.length-1, 'Updated Tab', container);
		
		
		this.smartItems = Array.from(document.querySelectorAll('smart-tab-item'));
					
    });
  }

  loadComponent(viewRefAnchor: ViewRefAnchorDirective) {
    viewRefAnchor.viewContainerRef.clear();
    return viewRefAnchor.viewContainerRef.createComponent(ThingComponent);
  }
}

Hope this helps.

Regards,
Peter

[dilbert]

That works.  Thanks!

[Author]

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