title: Create a simple shopping cart in wordpress?
body: <p>I have a wordpress website, and I want to create a simple web commerce. When I mean simple, it's really simple: Some posts/pages are going to have a custom field named "price". These pages are going to have a link on it, and clicking on it, the user is going to be sent to a simple shopping cart. From the shopping cart, I'm going to create a checkout page, which is mainly a php page that connects to a payment gateway, showing credit cards and such. I'm going to create php files that validates info about these payments after the response from the gateway.</p>
  
  <p>I'm not going to sell "products". I don't need postal offices, no address to deliver something, nothing. It's just a price and a php that receives confirmation from the payment gateway. Think of selling "courses" or something like that. A receipt of the buy is going to be in the database, so the client can reference it later.</p>
  
  <p>So, I think I need to create:</p>
  
  <ul>
  <li>A shopping cart page. This shopping cart can be made using cookies or the database. Which is the best approach?;</li>
  <li>A checkout page;</li>
  <li>A bunch of scripts to validate a response from the payment gateway;</li>
  <li>A simple table that stores all the payments responses, containig price, user_id and such.</li>
  </ul>
  
  <p>Am I forgetting something? What else should I be aware of when trying to create this plugin? I heard that wordpress don't use sessions, so I would need to create one in wordpress just for the carts. Does anyone knows about this issue?</p>
  
  <p>(I don't want to use these complete e-commerce plugins that exist since I don't need all their features.)</p>