function check() { if (!$this->hasCheckbox) { return parent::check(); } $value = $this->container->data[$this->ref]; if ($value != $this->valueOnCheck && $value != $this->valueOnUncheck) { return $this->container->errors[$this->ref] = jForms::ERRDATA_INVALID; } if ($value == $this->valueOnCheck) { // the checkbox is checked, let's check children return parent::check(); } // the checkbox is NOT checked return null; }