When adding duplicate items to cart, list them separately as individual items

[rfwoolf]

Does anybody have any idea how I would go about making this happen?

In application_top.php it will try to UPDATE a product when you add it to your cart the second time - but if I get it to INSERT the product, would it work?

Any advice?

 

Thanks! :)

[rfwoolf]

Listening

[Actually I posted this reply by mistake, then edited to so I don't look like a complete moron...]

[rfwoolf]

I have been fighting with this for several hours now and I think I understand the problem - but don't know the solution...

 

The $cart class stores the shopping cart in an array called $contents :

$cart->contents

When you add a product to the cart, *IF* it's already in the cart, *THEN it *updates* the existing item's quantity, *ELSE* it adds a new product to the $contents

So you just comment out the 'update' part, right? That would force it to keep on adding *new* items to the cart -- exactly what we want.

BUT there's a problem!

In php arrays, you cannot have duplicate keys, this means if you INSERT into $contents a new array key of your product "123" and then fill that array with the products data, and then you try and INSERT again, it will *OVERWRITE* the existing entry!!!!

Effectively, inserting a product twice, over-writes the existing product :(

[rfwoolf]

Okay I found a solution - just needs some proper and thorough testing.

 

As per my previous post, you need to make every product added to $cart->content unique, so that it doesn't *update* the product every time.

So in the add_cart function, I've done this:

CHANGE THIS:

$products_id_string = tep_get_uprid($products_id, $attributes);

TO THIS:

$products_id_string = tep_get_uprid($products_id, $attributes) . '[' . (string)count($this->contents) .']';

 

This takes the product ID e.g."28{8}17{7}15{9}19", and adds a COUNT of the existing items in your cart, so for example:

28{8}17{7}15{9}19[0] (if your cart was empty)

28{8}17{7}15{9}19[1] (after adding again)

28{8}17{7}15{9}19[2] (after adding again)

11[3] (a new product was added to the cart!)

28{8}17{7}15{9}19[4] (after adding again)

 

This way, every item in your cart is uniquely identified, and can still be 'traced' in your catalogue because if you say int($products_id_string) it takes the int at the beginning, i.e. 28.

Similarly, elsewhere in the code it will need to do something with the product ID, and int($product_id) fetches only the first part :D

 

Okay - I'm off to do some testing...

[rfwoolf]

Well there are some minor problems...

 

First:

by appending '[X]' to the end of our product names to make it unique (where X is a count of cart items), if the customer is signed in, this new productID is also stored into the tables in add_cart and remove: TABLE_CUSTOMERS_BASKET and TABLE_CUSTOMERS_BASKET_ATTRIBUTES.

I will have to test if this gives any problems later in the process, like at checkout.

 

Second,

there's a problem on the shopping_cart.php page if you make changes to the quantity and click "Update".

However, *removing* items seems to work just fine.

The update button calls the action "update_product" which is in application_top.php

update_product then calls cart_add (which is in classes/shopping_cart.php), but with the NEW PRODUCT ID (with the extra '[X]', and that's the problem:

cart_add performs a bunch of checks on the product_ID (like where it is active and in stock etc) and tries to explode the products attributes (which now have an extra [X] at the end.

[rfwoolf]

Another problem with my solution:

Appending

'[' . (string)count($this->contents) .']';

to the end of

$products_id_string

puts the count of the number of items in the cart.

But it should really be a unique number - so count($this->contents) should really be something like FetchNextID

[rfwoolf]

Just a note: in the end I abandoned this idea, although someone that was better at PHP would probably have been able to finish.

The whole idea shouldn't be necessary. I thought it was necessary for me because I was not using the Qty like a normal site - my Qty was my weight, e.g. 0.1, so if I add 0.1 and 0.5 I want it to list 0.1 and 0.5, not 0.6.

So I found a fix that allows you to use weight as an ATTRIBUTE, allowing you to keep the Qty. So now if I add 1 x 0.1 and 1 x 0.5 it lists them separately anyway, because items with two different attributes get listed separately.

So I guess another workaround for this problem is to simply add an attribute for the Qty that the user adds.

Example: If they put 0.5 as their quantity, it will somehow add an attribute with value '0.5' (which you can hide from the user or show and just ignore it).