Angular 4 Inherited Formcontrol

user_5260565 0
Viewed 2669

I am trying to create a subclass of FormControl with some additional properties which can then be used inside my custom form controls to change the behaviour.

I tried to inherit from FormControl(say StandardFormControl) as below and used to create a form group but when I access the formcontrol inside a directive/anywhere else, I do not get the properties of the subclassed form control.

class StandardFormControl extends FormControl{
   customProperty: string
}

The form group was created as below

new FormGroup({
  firstName: new StandardFormControl('',[])
});

Anyone has any ideas?

angular4-forms angular
2 Answers

As far as I know you have to typecast the form control:

// first create the form group and store it in a variable:
const formGroup = new FormGroup({
  firstName: new StandardFormControl('',[])
});

// then you can access its controls:
(formGroup.get('firstName') as StandardFormControl).customProperty = 'customValue';
user_38582710

You have to call super() in constructor to inherit the parent class.

class StandardFormControl extends FormControl{

    customProperty: string

    constructor() {
       super();
    }    
}
user_39407340
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