falsy

Validate that the value is falsy in the JavaScript sense — i.e. Boolean(value) evaluates to false.

Signature

NguardValidators.Boolean.falsy: ValidatorFn

Accepts: false, 0, '', null, undefined, NaN. Rejects everything else.

Reactive forms

import { FormControl, FormGroup } from '@angular/forms';
import { NguardValidators } from 'ng-nguard';

const form = new FormGroup({
    optedOut: new FormControl(false, [NguardValidators.Boolean.falsy]),
});

Template-driven forms

<input ngModel name="optedOut" nguardFalsy />

Error key

{ falsy: true }

Notes

• Strings like 'false' and '0' are truthy in JavaScript (they are non-empty strings) and therefore fail this rule. If you want Laravel-style decline semantics, use declined.

See also

• truthy — opposite check
• declined — Laravel-style decline set
• boolean — strict boolean-like type check