Is it possible to declare an empty form group then add form controls afterwards inside the onInit fu-CodePudding

As title, how can I declare an empty form group then add form controls afterward? I tried passed in a null or not passing anything at all, its just won't let me do it.

this.demoForm = new FormGroup(null);//DON'T WORK

Any work around? Thankyou.

CodePudding user response：

You can create a new empty FormGroup

const formGroup = new FormGroup({});

and then add a new FormControl/FormGroup/FormArray (to be precise AbstractControl, which is the base class of these three)

const formControl = new FormControl();
formGroup.addControl('controlName', formControl);

For more information you can find the addControl documentation here: https://angular.io/api/forms/FormGroup#addcontrol