javascriptangulartypescriptangular-signals

Using Angular Signals with HostBinding to update style?

In a app-test component I have the following:

  @Input( { transform: booleanAttribute})
  reverse: boolean = false;

  @HostBinding('style.flex-direction')
  direction: string = this.reverse ? 'column-reverse' : 'column';

And so if the designer applies the reverse attribute to app-test like this:

<app-test reverse></app-test>

Then Angular should set style="flex-direction: column-reverse" on the app-test element.

And I'm wondering how to use Angular signals so that when reverse is set to true, direction will be set to column-reverse. Thoughts?

Solution

  • This is being discussed in this issue. Currently the combination of @HostBinding and signals is not supported.

    The workaround for this is to use a getter:

    reverse = input.required<boolean>();

@HostBinding('attr.style.flex-direction')
get direction() { return this.reverse() ? 'column-reverse' : 'column' }