Guardian::checker('this_is_url', function ($input) { return filter_var($input, FILTER_VALIDATE_URL); }); // Check for email address Guardian::checker('this_is_email', function ($input) { return filter_var($input, FILTER_VALIDATE_EMAIL); }); // Check for boolean value Guardian::checker('this_is_boolean', function ($input) { return filter_var($input, FILTER_VALIDATE_BOOLEAN); }); // Check whether the input value is too large Guardian::checker('this_is_too_large', function ($input, $max = 3000) { return is_numeric($input) ? $input > $max : false; }); // Check whether the input value is too small Guardian::checker('this_is_too_small', function ($input, $min = 0) { return is_numeric($input) ? $input < $min : false; }); // Check whether the input value is too long Guardian::checker('this_is_too_long', function ($input, $max = 3000) { return is_string($input) ? strlen($input) > $max : false; }); // Check whether the input value is too short Guardian::checker('this_is_too_short', function ($input, $min = 0) { return is_string($input) ? strlen($input) < $min : false; }); // Check whether the answer is incorrect Guardian::checker('this_is_correct', function ($a = true, $b = false) { return $a === $b; });