addControl to FormGroup dynamically in Angular

Issue

How can I add a FormControl to a FormGroup dynamically in Angular?

For example, I would like to add a mandatory control which name is "new" and its default value is ''.

Solution

addControl is what you need. Please note the second parameters must be a FormControl instance like so:

this.testForm.addControl('new', new FormControl('', Validators.required));

You can also add the validators dynamically if you want with the setValidators method. Calling this overwrites any existing sync validators.

Answered By - Siro