FormArray helpers to remove controls.

[MarioArnt]

I'm submitting a...

[ ] Regression (a behavior that used to work and stopped working in a new release)
[ ] Bug report  
[ ] Performance issue
[ x] Feature request
[ ] Documentation issue or request
[ ] Support request
[ ] Other... Please describe:

Hello,

I'm using the lib and it would be great if there was more methods to remove controls from FormArray

Currently there's only a removeAt(index: number) method (inherited from @angular/forms) which is not very convenient to remove a control by value or by a given predicate.

I am thinking about something like this in the FormArray class:

removeWhen(predicate: (value: T) => boolean) {
  for (let i = 0; i < this.length; ++i) {
    if (predicate(this.at(i).value)) {
      this.removeAt(i);
    }
  }
};

remove(value: T) {
  this.removeWhen((v) => v === value);
};

I can make a PR if you are interested by such a feature 🚀

Thanks for your work 👍

BTW, the link to the repo is outdated on NPM, you should update repo field

[NetanelBasal]

Sounds good. We just need to think about a better name. You can submit a PR.

[danzrou]

I suggest providing the whole control in the predicate as we might want to consider disabled or other control states too

[MarioArnt]

@NetanelBasal I created PR #41 for this, feel free to suggest other names for the new methods

Good point @danzrou ! I provided the whole control so it is possible to use any property (disable, dirty, status etc...) in the predicate