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Add item to cart based on quantity of another item

Thread began 6/15/2009 6:15 am by hmyrick308645 | Last modified 6/15/2009 8:07 am by Ray Borduin | 1178 views | 1 replies |


Add item to cart based on quantity of another item

I am working on a cart where for every 2 of one item, 1 of another item must be in the cart. The relevant items/columns in the DB are:

ID 1, ItemCatID 1
ID 2, ItemCatID 1
ID 3, ItemCatID 1
ID 4, ItemCatID 2

When a customer adds any of the items with ItemCatID 1, Item ID 4 should be added to the cart in a 1:2 ratio. For every two of any combination of items from ItemCatID 1, there should be 1 of Item ID 4.


ID 1: Qty 2
ID 2: Qty 1
ID 3: Qty 3
Total of items in ItemCatID 1 = 6
ID 4 should have 3 added to the cart.

For fractions, I'll round up.

If the customer updates the quantity of items in ItemCatID 1, the quantity of Item ID 4 needs to update accordingly to half the quantity, rounded up.

(Later, there may be more items added, so I would like to make this as flexible as possible so new items don't break it, if possible, but that is not the main issue now).

I know this is probably very simple, but I can't figure it out. Should I create a calculation in the cart object and reference that later?

Any suggestions would be appreciated.

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Ray BorduinWebAssist

Unfortunately this is not very simple.

I think it would require writing a loop on the cart page that would do the checking and update the associated quantities.

I don't think calculations or any eCart interfaces will really help with this since it involves adding and removing items from the cart, which calculations can't do. You may be able to use a calculation to do the math to figure out how many items should be added or what the correct quantity might be, but you are going to have to hand code the actually functionality, so you might as well do the calculations in the php while you write it.

Sorry for the bad news, but the advice is don't use any WA interfaces and instead write this functionality by hand.... most likely on the top of the cart page would be enough.

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