Validating forms

Defining relationship validators

Relationship validators can be added by defining a validators object:

user.form-object.ts

import { Validators } from '@angular/forms';
...

validators: {
  name: Validators.required, // User must have a name
  cars: (carsControl: AbstractControl) => {
    return carsControl.value?.length >= 1 : null : { error: 'User must have at least 2 cars' };
  },
}
...

These validators will be passed to the corresponding name and cars form controls.

note

Validator object will be used only for Attribute and HasMany relationships. For validating BelongsTo relationships, see FormGroupOptions.

Defining FormObject validator with FormGroupOptions

To validate a FormStore instance as a whole, a validator can be provided via formGroupOptions on FormObject.

This can be used for validating the BelongsTo relationships.

user.form-object.ts

import { Validators } from '@angular/forms';
...
public formGroupOptions: FormGroupOptions = {
  validator: (form: FormStore) => {
    ...
  },
};
...