How to get the name of FormControl which got updated using valueChanges?

Question

In a form group that is dynamically generated with different FormControl names, valueChanges() is emitting the whole array. How we can identify the exact FormControl name which got updated?

Answer 1

You can listen to the FormControl itself like this

formGroup.controls.forEach(element => {
   formGroup.get(element).valueChanges = onControlValueChange;
});

onControlValueChange(v){
     // doTheJobHere();
}

You can also follow the same logic for FormArray

formArray.forEach(item => {
  (formArray[item].controls||[]).forEach(element => {
         formArray[item].get(element).valueChanges = onControlValueChange;
     });
});