错误：在Cakephp 3中尝试使用AJAX发布数据时出现错误请求

Question

我想使用AJAX发布一个表单，因为我创建了一个表单，当我在控制器中放入这两行代码时工作正常：

  

$ this-＆gt; Security-＆gt; config（＆＃39; unlockedFields＆＃39;，[＆＃39; product_id＆＃39;]）;

     

$这 - ＆GT;安全 - ＆GT;配置（＆＃39; unlockedActions＆＃39;，阵列（＆＃39;更新＆＃39;））;

如果删除此代码我

  

错误：控制台中的错误请求。

<?php echo  $this->Form->create('Cart',array('id' => 'saveForm'));

      $total=0;
      foreach ($products as $product):           
      echo $product['product_name'];
      echo $this->Form->input('product_id.',array('value'=>$product['product_id'],'type' => 'number')); 
      echo $this->Form->input('count.',array('type'=>'number', 'label'=>false,
                'class'=>'form-control input-sm', 'value'=>$product['count']));
      echo $product['count']*$product['product_price'];
      endforeach;
      echo $total;           
      echo $this->Form->submit('Save');  
      echo $this->Form->end();

      ?>

  

控制器操作：

public function update() {

    $this->autoRender = false;

     if (!empty($this->request->data)) {
            $cart = array();

            foreach ($this->request->data['count'] as $index=>$count) {
                if ($count>0) {
                    $productId = $this->request->data['product_id'][$index];
                    $cart[$productId] = $count;
                }
            }

            $this->Carts->saveProduct($cart);

             $carts = $this->Carts->readProduct();
    $products = array();
    if (null!=$carts) {
        foreach ($carts as $productId => $count) {
            $product = $this->Products->get($productId);
            $product['count'] = $count;
            $products[]=$product;
        }
    }
    $this->set('products', $products);
    $this->render('cart_view');
    $this->set(compact('products'));

        } 

}

  

index.ctp

 $(document).on("submit", "#saveForm", function(ev) {   
            var formData = $('#saveForm').serialize();
            var formUrl ="http://localhost/multi_shopping/Singles/update";
            $.ajax({
                type: 'POST',
                url: formUrl,
                data: formData,
                dataType: 'html',
                async   :   false,
                success: function(data,textStatus,xhr){
                         $('#PPMiniCart').html('');
                         $('#PPMiniCart').html(data);
                        $('#PPMiniCart').show();
                },
                error: function(xhr,textStatus,error){
                        alert("error"+error);
                }
            }); 
             ev.preventDefault();   
            return false;
        });