reading required signal input from effect causes error NG0950 when done inside structural directive creating an embedded view after promise resolves about angular HOT 5 OPEN

I've edited the issue to provide a minimal structural directive that reproduces the issue. All it takes is the following, which looks quite innocent to me:

export class FooDirective implements OnInit {
  private tpl = inject(TemplateRef);
  private vcr = inject(ViewContainerRef);

  ngOnInit() {
    Promise.resolve().then(() => {
      this.vcr.createEmbeddedView(this.tpl, {});
    });
  }
}

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Thank you for the excellent minimal reproduction.

Yep, this is indeed a bug. Digging in, the problem seems to be with the ChangeDetectorRef trick we're using in effect() to know if we're inside a view that has been initialized or not.

When BugDirective calls effect(), we use the LView to decide if the first update pass is already complete (see the code). The ChangeDetectorRef though gives us the LView of the parent component, which of course has already been initialized. Thus we don't defer the effect from scheduling immediately, causing the issue.

from angular.

Hi JB !
Is there any reason you opened the issue on the FW and not the transloco repo ? Structural directives provided by the framework like NgIf don't have this issue. It look like it's a problem the way transloco projects the content of the directive.

from angular.

Hi Matthieu

I assumed that whatever Transloco is doing in its directive shouldn't have an impact on how Angular schedules the execution of an effect: it should be executed after the input has been set, and not before.
Isn't that a reasonable assumption?

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The first effect execution is scheduled to run during the first CD. Transloco is probably triggering a CD before the input has been set.

from angular.