我有一个简单的控制器，用于将行添加到表中，但是如果失败，我希望与之保持同一页面，但仅带有flash警告消息。

class WarehouseAddressesController{
    public function itemToAdd($id = null){
        $exists = $this->ItemsAddress->find('first',array('conditions' => array(
            'warehouse_addresses_id' => $this->request->data['WarehouseAddress']['id'],'items_id' => $this->request->data['Items']['itemToAdd'])));

        if($this->request->is(array('post')) && empty($exists)){
            $data = array(
                'warehouse_addresses_id' => $this->request->data['WarehouseAddress']['id'],'items_id' => $this->request->data['Items']['itemToAdd']
            );

            if ($this->ItemsAddress->save($data,array('validate' => 'first',))) {
                $this->flash->success(__('This item has been successfully added to the requested address.'));
                $this->redirect($this->referer());
            }
            if(!empty($exists)){
                $this->flash->warning(__('This item already exists on this address'));
                $this->redirect($this->referer());
            }
            else {
                $this->flash->error(__('This item could not be added to this address. Please,try again.'));
                $this->redirect($this->referer());
            }}}}

保存项目时，它会像使用$ this-> referer一样保留在同一页面上，但是当项目存在时，它显示错误错误：找不到WarehouseAddressesController :: itemToAdd（）的视图。 但是我想留在页面上，只是显示页面存在的错误。