title: Add custom data to cart item in Magento 1.6
body: <p>I've been reading a <strong>lot</strong> of tutorials around the internet, but even the ones on the Magento site are for version 1.5 or <em>less</em> and even some of the functions references do not exist any longer.</p>
  
  <p>What I am doing is simple, I am sending a item to a custom script outside of Magento where the user makes a design and then the customer can click <em>Add to Cart</em> from there and its added back to Magento.</p>
  
  <p>What I need is have the designed image file names be a line item-specific piece of data that is displayed in the order process and the view order history for both client and administration.</p>
  
  <p>I have a module that hooks into <code>checkout_cart_product_add_after</code> and is able to get the following information: <code>designs</code> and <code>designId</code>. <code>designId</code> is used in the event the user goes back to edit the design, so the design is re-loaded and then when the item is passed back, the <code>designs</code> and <code>designId</code> contents should be replaced if different.</p>
  
  <p>At the moment, I am adding the product to the cart via URL because examples on how to add it pragmatically worked to a certain extent, but ultimately fail to save to the cart. Difference between the <code>STORE_ID</code> and some random glitch in the Magento code, I assume.</p>
  
  <p>I appreciate pointers to more solid information than just plowing through old documentation to see if there is anything useful to get out of it, it has gotten me this far but its not an effective method of getting things done properly.</p>