Forms

To programmatically set an Angular control as invalid, you can use the setErrors() method of the AbstractControl class. This method allows you to set an error object on the control that will indicate that it is invalid.

Here is an example of how you can use setErrors() to set a control as invalid.

In this example, the setControlInvalid() method is used to set the name control as invalid by calling the setErrors() method on it and passing in an error object with the key invalid set to true. This will cause the control to be marked as invalid and will display the appropriate validation message if a validation message is defined for the error key.

To dynamically add a FormControl to an Angular form, you can follow these steps:

1. Import the FormBuilder class from the @angular/forms module at the top of your component
2. Inject the FormBuilder service in your component's constructor
3. Create a new FormGroup using the FormBuilder
4. To dynamically add a FormControl, you can use the addControl method on the FormGroup
   
   This will add a new FormControl with the name "myControlName" to the FormGroup. The second parameter to the FormControl constructor is the initial value of the control.

You can add as many controls as you need, and you can also remove controls using the removeControl method on the FormGroup.