Which @angular/* package(s) are relevant/related to the feature request?

compiler-cli

Description

Sometimes directives are created to simplify repetitive behaviors that clash with using the host element properties or events directly, for example a myButtonStyle directive that don't want the user to add class or style attributes directly to the button elements. Or a myButtonAction that internally listen to click events and don't want users of the directive to use click bindings on the template.

Proposed solution

Allow something like:

@Directive({
  selector: 'button[myButtonStyle]',
  reject: ['class', 'style'],
})

For the properties case, or:

@Directive({
  selector: 'button[myButtonAction]',
  reject: ['(click)'],
})

For the events case.

Alternatives considered

For the properties case, defining an input of type never works, but there is no way to indicate the user the reason why using style on the template is discouraged by the directive author.

readonly style = input<never>();

There is no alternative for the output or events case.

Note: The proposed solution nor the alternative has a way to discourage directly using the DOM to set properties or add listeners, but this is true too for everything the templating engine does, so adding these checks to the template compiler can be useful on the template authoring workflow