Opencart 2.x Undefined Index product.php

Question

I am trying to figure out an issue with an undefined index error when a product is saved or edited.

I have created a new entry in the product table in the database called disable_cart which is set to int(1) and has a default value of 0.

On the product_form.tpl it is simply a checkbox.

    <div class="col-sm-10">
              <div class="checkbox">
                 <label>
                  <?php if ($disable_cart) { ?>
                  <input type="checkbox" name="disable_cart" value="1" checked="checked" id="input-disable_cart" />
                  <?php } else { ?>
                  <input type="checkbox" name="disable_cart" value="1" id="input-disable_cart" />
                  <?php } ?>
                  &nbsp; </label>
              </div>
            </div>

The code in the product controller

    if (isset($this->request->post['disable_cart'])) {
        $data['disable_cart'] = $this->request->post['disable_cart'];
    } elseif (!empty($product_info['disable_cart'])) {
        $data['disable_cart'] = $product_info['disable_cart'];
    } else {
        $data['disable_cart'] = 0;
    }

And the model in the addProduct() function

public function addProduct($data) {
    $this->event->trigger('pre.admin.product.add', $data);

    . "', disable_cart = '" . (int)$data['disable_cart'] . "', date_added = NOW()");

Same in the editProduct() function. It works fine on my localhost but only works on the dev server if the checkbox is ticked otherwise I get the following error

Undefined index: disable_cart in /admin/model/catalog/product.php on line 134Warning: Cannot modify header information - headers already sent by (output started at /admin/index.php:80) in /system/library/response.php on line 12

Can't figure out the issue, any help is greatly appreciated.

Thanks

edit: The value does save in the DB but it still throws the error

Answer 1

Your problem is due to the fact that an unchecked Checkbox will not be sent through post

1. So there is no post['disable_cart'] .

2. When you post a new product or make an edit, this part of the code is called:

    if (($this->request->server['REQUEST_METHOD'] == 'POST') && $this->validateForm()) { $this->model_catalog_product->addProduct($this->request->post); 

$data['disable_cart'] has not been defined at all . so the addProduct function will throw an exception.

The solution is to add this line of code:

if (($this->request->server['REQUEST_METHOD'] == 'POST') && $this->validateForm()) {
   // add this line to `add` and to `edit`
   if(!isset($this->request->post['disable_cart'])) $this->request->post['disable_cart'] = 0;

   $this->model_catalog_product->addProduct($this->request->post); 
...

As for the warning, it is simply saying that you have a premature output due to the error being thrown.