Input

Isset

Rule `isset`: Requires the field key to exist.

Usage

Strict payload shape validation.

$schema = \Lemonade\Framework\Validation\ValidationSchema::create()
    ->field('field', 'Field')
        ->custom('isset')
        ->end();

$result = $validator->validate($payload, $schema);

Stable rule name

isset for translations, registry lookup and per-rule messages.

Group

Required / Conditional