Backend\ModuleBuilderController::getFormFields PHP Method

    public function getFormFields($id, $module_id = null)
    {
        $form_id = (int) $id;
        $ret = [];
        if ($form_id != 0) {
            // if form id is specified
            $form = BuiltForm::find($form_id);
            $form_fields = $this->moduleBuilder->getFormFields($form->data);
            $ret = array_combine($form_fields['fields'], $form_fields['field_names']);
        } else {
            if ($module_id) {
                $module = BuiltModule::find($module_id);
                $model = $id;
                $module_models = json_decode($module->models, true);
                $module_fields = json_decode($module->form_fields, true);
                $model_index = array_search($model, array_keys($module_models));
                if ($model_index !== false) {
                    $ret = $module_fields[$model_index];
                }
            }
        }
        return $ret;
    }