I have a use-case where I'm creating several custom formgroup classes that have FormGroup as their parent class like so:

export class CustomFormGroup1 extends FormGroup {
  //a bunch of custom properties for this FormGroup
  
  constructor() {
    super(
      {
      // initializing CustomFormGroup1's form properties
      }
    );
  }
}

export class CustomFormGroup2 extends FormGroup {
  //a bunch of custom properties for this FormGroup
  
  constructor() {
    super(
      {
      // initializing CustomFormGroup2's form properties
      }
    );
  }
}

// etc with a couple more Custom Forms

What I'm trying to do is put this in an array who's type is FormGroup, i.e.:

formList: FormGroup[] = [CustomFormGroup1, CustomFormGroup2, ...etc]

When I do this, I get the following error:

TS2740: Type 'typeof ResourceTypeForm' is missing the following properties from type 'FormGroup': controls, registerControl, addControl, removeControl, and 57 more. 

I've found a few questions similar to my issues like: Type 'AbstractControl' is missing the following properties from type 'FormGroup': controls, registerControl, addControl, removeControl, and 3 more or TypeScript type of array with common Classes that inherit from same Class but none that are similar enough to my issue.

In short, what I'm asking is: Is there a way to type an array where objects in that array have the same parent class?

I do understand that I could theoretically just define all the methods for FormGroup in CustomFormGroup1 and CustomFormGroup2, but I'm hoping there's a way I can get the desired result without having to do that.

I have also tried defining it like this:

formArray: (FormGroup|CustomFormGroup1|CustomFormGroup2|..etc)[] = [CustomFormGroup1, CustomFormGroup2, ...etc];

I get the same warning mentioned above.

Thank you very much in advance for any insight.

Thank you in advance.

CodePudding user response：

To have types that are subclass of FormGroup (or FormGroup itself) in the array you can use something like:

formList: (typeof FormGroup)[] = [CustomFormGroup1, CustomFormGroup2, ...etc]