How to limit the value type of FormGroup in ts?

Question

I have a constant like this:

const defaultInfo: FormGroup = this.fb.group({
  id: 1,
  name: qian,
  amount: 123,
})

And I want to limit the types inside FormGroup, so I write like this:

interface InfoInterface {
  id: number,
  name: string,
  amount: number,
}


interface InfoFormGroup extends FormGroup {
  value: InfoInterface
}

const defaultInfo: InfoFormGroup = this.fb.group({
  id: 1,
  name: qian,
  amount: 123,
})

Apparently it doesn't work because no matter what I change the properties of the Info Interface to, there are no errors, why? How to limit the value type of FormGroup in ts

Restrict the value type of FormGroup in ts

Answer 1

I think it should help you: https://angular.io/guide/typed-forms

Basically you need to make the interface have form controls instead of normal types:

interface InfoInterface {
      id: FormControl<number>,
      name: FormControl<string>,
      amount: FormControl<number>
  }
    
  const info = new FormGroup<InfoInterface>({
      id: new FormControl(0),
      name: new FormControl(''),
      amount: new FormControl(0)
  });

Please keep in mind that it was introduced in Angular 14, so it will not work in previous versions