x.ts

abstrac class Base {

    markAllDirty(control: AbstractControl) {
        if (control.hasOwnProperty('controls')) {
            control.markAsDirty(true); // mark group
            let ctrl = <any>control;
            for (let inner in ctrl.controls) {
                this.markAllDirty(ctrl.controls[inner] as AbstractControl);
            }
        }
        else {
            (<FormControl>(control)).markAsDirty(true);
        }
    }

    markAllPrestineAndUntouched(control: AbstractControl) {
        if (control.hasOwnProperty('controls')) {
            control.markAsPristine(true); // mark group
            control.markAsUntouched(true); // mark group
            let ctrl = <any>control;
            for (let inner in ctrl.controls) {
                this.markAllPrestineAndUntouched(ctrl.controls[inner] as AbstractControl);
            }
        }
        else {
            (<FormControl>(control)).markAsPristine(true);
            (<FormControl>(control)).markAsUntouched(true);
        }
    }

}