奇怪的CI3购物车更新问题

Question

使用Codeigniter 3和本机购物车库。当我更改数量并更新购物车时，如果我从1更改为2，它可以正常工作。如果我改为3或更高，我会得到错误，虽然它仍然将数量更新为3.如果我然后改回1我得到错误，一旦回到1我再次改为2确定。

错误：

Severity: Notice

Message: Undefined offset: 1

Filename: models/Cart_model.php

Line Number: 60

第60行是

 'rowid' => $item[$i]

购物车：

<?php echo form_open('cart/update'); ?>  
                  <table class="table">
                    <thead>
                      <tr>
                        <th class="text-center"><i class="fa fa-shopping-cart"></i>
                        </th>
                        <th>Product Name</th>
                        <th>Quantity</th>
                        <th>Total</th>
                        <th></th>
                      </tr>
                    </thead>
                    <tbody>
                        <?php $i = 1; ?>

                        <?php foreach ($this->cart->contents() as $items): ?>
                        <?php echo form_hidden('rowid[]', $items['rowid']); // We added an hidden field which contains a unique id in array format, this is needed in order to update ?>

                      <tr>
                        <td class="table-first">

                          <img class="img-responsive" src="<?= site_url('assets/images/shop/CreamseedBoilies.jpg') ?>" alt=""/>
                        </td>
                        <td>
                          <span class="title"><?php echo $items['name']; ?></span>
                        </td>
                        <td>
                          <?php echo form_input(array('name' => 'qty[]', 'value' => $items['qty'], 'maxlength' => '3', 'size' => '5')); ?>
                        </td>
                        <td>
                          <span><?php echo $this->cart->format_number($items['price']); ?></span>
                        </td>
                        <td class="close-cart">
                          <a href="<?= site_url('cart/remove/'.$items['rowid']) ?>" class="btn btn-primary btn-sm"><i class="fa fa-times"></i>
                          </a>
                        </td>
                      </tr>
                      <?php $i++; ?>

                        <?php endforeach; ?>

                    </tbody>
                  </table>

                  <div class="panel-footer">
                    <div class="row">
                      <div class="col-sm-3">
                        <a href="<?= site_url('cart/empty') ?>" class="btn btn-default btn-sm">Empty Cart</a>
                      </div>
                      <div class="col-sm-9 text-right">
                        <button type="submit" class="btn btn-default btn-sm">Update Cart</button>
                        <a href="#" class="btn btn-primary btn-sm">Proceed to checkout</a>
                      </div>
                    </div>
                  </div>
                  <?php echo form_close() ?>

购物车更新方法：

        public function update()
{

        $this->cart_model->validate_update_cart();
        redirect('cart');


}

购物车型号：

function validate_update_cart(){

// Get the total number of items in cart
$total = $this->cart->total_items();

// Retrieve the posted information
$item = $this->input->post('rowid');
$qty = $this->input->post('qty');
// Cycle true all items and update them
for($i=0;$i < $total;$i++)
{
    // Create an array with the products rowid's and quantities. 
    $data = array(
       'rowid' => $item[$i],
       'qty'   => $qty[$i]
    );

    // Update the cart with the new information
    $this->cart->update($data);
}

}

Answer 1

原来：

$total = $this->cart->total_items();

不提供总计独特的产品（rowid），而是提供包含一种产品的倍数的项目。因此，$ total和total items的大小并不匹配。

正确的方式：

function validate_update_cart(){

// Get the total number of items in cart

// Retrieve the posted information
$item = $this->input->post('rowid');
$qty = $this->input->post('qty');

$total = count($item);
// Cycle true all items and update them
for($i=0;$i < $total;$i++)
{
    // Create an array with the products rowid's and quantities. 
    $data = array(
       'rowid' => $item[$i],
       'qty'   => $qty[$i]
    );

    // Update the cart with the new information
    $this->cart->update($data);
}

}