Discussion on: Wrapping Angular Material button in custom Angular component (part 2)

[Dzhavat Ushev]

I got some suggestion for how to fix this on Twitter. Looks like using pointer-events: none when the button is disabled fixes the issue. Created a StackBlitz :)

[Benoît Plâtre]

Hi Dzhavat,
Yes that's what I did but I think it's not ideal. I think it's more safe to listen to the real button target click event.
I tried another approach, creating the Component manually and listening directly to the button instance. Then emitting a btnClick event with the event coming from the real button. My button wrapper is pointer-events:none, always, and only the child button is pointer-event:auto.
Here is the template :

<ng-template #buttonContainer></ng-template>
<div #contentWrapper>
    <ng-content></ng-content>
</div>

Here is the buildComponent function :

#buildComponent() {
    if (this.buttonContainer && this.#variant && !this.componentRef) {
      this.componentRef = this.buttonContainer.createComponent<ButtonTemplate>(
        this.buttonComponentVariant,
        {
          injector: this.buttonComponentInjector,
          projectableNodes: [[this.contentWrapper.nativeElement]],
        }
      );
      this.componentRef.changeDetectorRef.detectChanges();
      if (this.componentRef.instance.target) {
        fromEvent(this.componentRef.instance.target.nativeElement, 'click')
          .pipe(untilDestroyed(this))
          .subscribe((event: any) => {
            this.btnClick.emit(event as PointerEvent);
          });
      }
    }
  }

My buttons implements the ButtonTemplate interface

export interface ButtonTemplate {
  target: ElementRef<HTMLButtonElement>;
}

I'm going on on with it, I'll let you know if it's fine. I plan also to manage not only <button> but <a> too, which may have the look of buttons.

[Benoît Plâtre]

Hi Dzhavat,
The way the component was created, with static providers, made the properties on the wrapper impossible to be bound on the final button component. Once the disabled property was set, it couldn't be updated.
I found a way to be able to update value from Wrapper to button instance.
I created a private validateDisabled function which update the button instance isDisables @Input (which is no more injected).

#validateDisabled(firstChange: boolean) {
    if (this.componentRef?.instance) {
      this.componentRef.instance.isDisabled = this.disabled;
      const changes = {
        isDisabled: new SimpleChange('', this.disabled, firstChange),
      };
      this.componentRef.instance.ngOnChanges(changes);
    }
  }

Calling ngOnChange on the dynamically created component seems to be the only way to force the update of the component's properties.
The ButtonTemplate now has more properties

export interface ButtonTemplate {
  target: ElementRef<HTMLButtonElement>;
  isDisabled: boolean;
  ngOnChanges(changes: SimpleChanges): void;
}

For example, here is the AccentButtonComponent

export class AccentButtonComponent implements ButtonTemplate, OnChanges {
  @Input()
  isDisabled = false;

  @ViewChild('target', { static: true, read: ElementRef })
  target!: ElementRef<HTMLButtonElement>;

  constructor(
    @Inject(typeAttributeToken) public type: BheButtonType,
    private cdr: ChangeDetectorRef
  ) {}

  ngOnChanges(changes: SimpleChanges): void {
    this.cdr.detectChanges();
  }
}

[Dzhavat Ushev]

Hey Benoît,
Thanks for sharing your solution. Appreciate it!
I haven't looked at it in details yet but will do that in the coming days and share my thoughts :)