ControlValueAccessor with default value

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

forms

Description

It would be nice if it was possible to create a ControlValueAccessor that is able to set default values on its own.

For the moment this is not possible, as calling the onChange function (function that we got a handle to via registerOnChange) will make the outer form dirty.

Proposed solution

Maybe add an extra method to the ControlValueAccessor interface for retrieving the initial value (“getInitialValue()”)?

Alternatives considered

As said, I tried to propagate the initial value in the registerOnChange method:

  form = new FormGroup({
    name: 'initial value'
  })

  registerOnChange(fn: (_: any) => void): void {
    this.onChange = fn;
   // propagate initial value
    fn(this.form.value);
  }

But this makes the outer form dirty, so it’s not really an option.

So for the moment the only possibility is that all users of the ControlValueAccessor has to set the initial value themselfves

[AndrewKushnir]

What do you think?

It sounds like it should be possible to handle in your custom ControlValueAccessor by adding extra logic (extra flags?). If there is a particular problem with the NgModel directive that you are observing (unrelated to your changes in the ControlValueAccessor), please create a new ticket with a minimal repro, so we can investigate further.

[angular-automatic-lock-bot[bot]]

This issue has been automatically locked due to inactivity. Please file a new issue if you are encountering a similar or related problem.

Read more about our automatic conversation locking policy.

_{This action has been performed automatically by a bot.}