Add To Cart validation does not take current Cart quantity into account [#1290842]

If ProductA has 5 in stock, and I add 5 or less to the Cart, I can continue to add 5 or less to the cart regardless of the cart's existing quantity.

Obviously moving to Checkout or updating the cart from the cart page reveals the stock validation error, however this still means the user has more items in their cart than they can purchase, and the stock levels are not automatically reduced, meaning that the user needs to manually lower the stock levels to get around the error.

Comment	File	Size	Author
#13	EntityMetadataWrapperException_v1_1290842_13.patch	833 bytes	guy_schneerson
#13
#11	line_item_type_check-1290842-11.patch	823 bytes	hibersh
#11
#8	take_cart_quantity_into_account-1290842-8.patch	2.57 KB	guy_schneerson
#8

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Comments

Comment #1

guy_schneerson CreditAttribution: guy_schneerson commented 26 September 2011 at 10:39

Priority:

Major

» Normal

Hi @carn1x,
Yes i am aware of this issue. The initial goal was to make sure users cant order out of stock items and make sure the module operates securely and with no errors, i was planning of adding this functionality as part of version 2 but may try and do it before as i agree it is not the best user experience.
i am downgrading priority to Normal, as most of the issues raised so far actually stooped the module from working as described above.

Comment #2

carn1x CreditAttribution: carn1x commented 26 September 2011 at 11:00

Thanks a lot :)

Comment #3

carn1x CreditAttribution: carn1x commented 3 October 2011 at 04:13

Ok in the interests of time, I hacked the commerce_stock.module and changed the following function:

function commerce_stock_add_to_cart_validate($form, &$form_state) {
  $qty = $form_state['input']['quantity'];
  $product_id = $form_state['input']['product_id'];                                                                                            
  $product = commerce_product_load($product_id);
  if (!(isset($product->commerce_stock_override['und']) && $product->commerce_stock_override['und'][0]['value'] == 1)) {
    if (commerce_stock_product_check_out_of_stock($product_id, $qty, $remaining_stock)) {
        form_set_error("stock_error", t('Maximum quantity of %title that can be purchased is %max', array('%title' => $product->title, '%max' => $remaining_stock)));
    }else{
      global $user;
      //load the current cart
      if ($order = commerce_cart_order_load($user->uid)) {
        $cart_qty = 0;
        //cycle throw each line item ID
        foreach($order->commerce_line_items['und'] as $line_item_id){
          //load each line item in the cart
          $line_item = commerce_line_item_load($line_item_id['line_item_id']);
          if($line_item->commerce_product['und'][0]['product_id'] == $product_id){
            //add the line item quantity to the quantity check
            $cart_qty += $line_item->quantity;
          }
        }
        $qty += $cart_qty;
        if (commerce_stock_product_check_out_of_stock($product_id, $qty, $remaining_stock)) {
          form_set_error("stock_error", t('Maximum quantity of %title that can be purchased is %max, and you already have %cart_qty in your shopping cart.', array('%title' => $product->title, '%max' => $remaining_stock, '%cart_qty' => $cart_qty)));
        }
      }
    }
  }
}

Since you're aware of this issue and working on V2, I won't bother rolling a patch, please anybody let me know if I can improve the code at all. Still very noobish regarding what functions commerce and entity API provides :)

Comment #4

guy_schneerson CreditAttribution: guy_schneerson commented 3 October 2011 at 11:35

Hi @carn1x,
looks good if you got time to add a patch i will include it in version 1, let me know if you don't and ill make the change when i get a chance.

Comment #5

joachim CreditAttribution: joachim commented 27 October 2011 at 18:02

Several points:

- this fix doesn't cover the case where one product node shows multiple products -- the commerce_stock_add_to_cart_validate validator is not added to the form in this case. we probably need a new, separate validator to handler already-in-cart stock checks
- secondly, I'm not sure this is the best way to deal with the use case. What if there are two widgets, and Alice adds one to her cart, then Bob adds one to his, and Alice adds one more to her cart? Who wins? Is it whoever reaches checkout first? Admittedly, this makes the whole stock control rather more complex, because it becomes a resource allocation system, and you have to build a system for releasing resources after a certain time. Basically, adding an item to your cart would mean you decrease stock count and have it for a certain time. Also, not all sites would necessarily want this model. One for another issue, I think.
- code style in the patch: comments should be full sentences; variables shouldn't use abbreviations; run the code through Coder module for other tweaks :)

Comment #6

joachim CreditAttribution: joachim commented 27 October 2011 at 18:03

Ah, my second point seems to be covered here: #1182404: Allow management of stock based on in-cart status of products

Comment #7

guy_schneerson CreditAttribution: guy_schneerson commented 27 October 2011 at 20:26

Thanks @joachim this patch is unlikely to go into the V1 as I have now started work on version two and will review this functionality for all cases.

Comment #8

guy_schneerson CreditAttribution: guy_schneerson commented 27 December 2011 at 14:39

Status:

Active

» Needs review

File	Size
take_cart_quantity_into_account-1290842-8.patch	2.57 KB

patch based on the stock V2 function for taking the current Cart quantity into account for the add to cart functions.

Comment #9

guy_schneerson CreditAttribution: guy_schneerson commented 10 January 2012 at 11:46

Status:

Needs review

» Fixed

committed http://drupalcode.org/project/commerce_stock.git/commit/4085e5f

Comment #10

24 January 2012 at 11:50

Status:

Fixed

» Closed (fixed)

Automatically closed -- issue fixed for 2 weeks with no activity.

Comment #11

hibersh CreditAttribution: hibersh commented 9 February 2012 at 04:55

Status:

Closed (fixed)

» Needs review

File	Size
line_item_type_check-1290842-11.patch	823 bytes

patch adds line item type check, avoid exception for entitymetadata wrapper

Comment #12

guy_schneerson CreditAttribution: guy_schneerson commented 9 February 2012 at 18:51

thanks @hibresh i think you solved an issue that was responsible for http://drupal.org/node/1411032#comment-5575072, I am going to look into this and a few other issues this weekend.

I think the correct way to handle this will be by making sure $line_item->type is in commerce_product_line_item_types().
missed that out :(