Changing quantity in AJAX cart page works only first time [#1421256]

Hi,

I've encountered a bug where the quantity of a product in the cart page can only be altered once. The second time the AJAX call fires and a message that the cart was updated is shown but the quantity remains unchanged.

I've enabled the update cart button again and when I press it right after changing the quantity it works as expected. Is this possibly a form validation error where a form is sent twice with the same form_build_id?

Cheers

Comment	File	Size	Author
#2	uc_ajax_cart-doublesubmitfix-1421256-2.patch	387 bytes	neilnz

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Comments

Comment #1

nelslynn CreditAttribution: nelslynn commented 30 January 2012 at 20:56

I've encountered something similar, only that after the first time to the cart page, and trying to change quantity, it dosn't work, althougth there is a successful update message. It takes a few times for the update cart to then work. After it works once, I can browse away from the cart page and then back to it, and the update function works as expected.

I've cleared cache, run update, and run cron.... neither of these help.

Using latest version of Dev uc_ajax-cart (jan 24) and ubercart 2.7

Comment #2

neilnz CreditAttribution: neilnz commented 21 March 2012 at 03:20

Status:

Active

» Needs review

File	Size
uc_ajax_cart-doublesubmitfix-1421256-2.patch	387 bytes

The reason for this is Ubercart 2.7 includes a hidden submit button at the top of the form that has the same ID (edit-update) as the one at the bottom. Of course this is extremely invalid, but to trigger the cart submit on change, triggerCartSubmit() in uc_ajax_cart.js uses this:

jQuery('#uc-cart-view-form #edit-update').trigger('click');

Because this actually matches two elements (!!), it clicks both update buttons. The first submit has valid form data, the second doesn't, and it triggers two refreshes of the cart contents, the first before the update has actually happened. It leads to a race condition, which is why the update works sometimes.

While Ubercart really need to sort out their CSS IDs on the form, this can be worked around by changing the click trigger to:

jQuery('#uc-cart-view-form #edit-update:first').trigger('click');

Attached a patch that does this.