replay-control-value-changes.ts

replay-control-value-changes.ts

export class ReplayControlValueChanges<T> extends Observable<T> {
    constructor(control: AbstractControl | AbstractControlDirective) {
        super(subscriber => {
            if (!control.valueChanges) {
                throw new Error('Control does not have valueChanges');
            }

            control.valueChanges.pipe(startWith(control.value)).subscribe(subscriber);
        });
    }
}