Is there a way to check whether control is required?
The problem arose when I implemented a dedicated form field component which accepts FormControl
and has not only input
but also validation errors. Since some field are required it's good to let the user know if it's required by *
.
Is there a way to check the @Input() control: FormControl
for Validators.required
and display an asterisk?
You can do something like this:
import { Component } from '@angular/core';
import { FormGroup, FormControl, Validators, AbstractControl } from '@angular/forms';
@Component({...})
export class AppComponent {
form: FormGroup = new FormGroup({
control: new FormControl(null, Validators.required)
});
get validator() {
const validator = this.form.get('control').validator({} as AbstractControl);
console.log(validator);
if (validator && validator.required) {
return true;
}
}
}
And then in your Template:
<form [formGroup]="form" (submit)="onSubmit()">
Control: <span *ngIf="validator">*</span> <input type="text" formControlName="control">
<button>Submit</button>
</form>
NOTE: Just get the form control as a type of AbstractControl
using this this.form.get('control').validator({} as AbstractControl);
This will return an Object with the list of validators that are present on your FormControl
. You can then check for the required
key in the Object. If it exists and its value is true
then you can be sure that a Required Validator is applied on the FormControl
.
Here's a Working Sample StackBlitz for your ref.