title: Full page cache, block update
body: <p>I want to implement Full Page Cache, but currently I have 1 issue to deal with.</p>
  
  <p>We work with E-Commerce system, which is based on Zend's and Varien library : Magento E-commerce Community Edition.</p>
  
  <p>I am able to cache output, the only problem is, how to deal with following situation:</p>
  
  <p>User comes to site, then goes to catalog/product and adds some product to cart, then goes back to catalog.</p>
  
  <p>The problem is that when he adds a product to cart, there are some particular blocks, which might need to be updated. So I can disabled caching post requests, but how I can update some particular block or how to implement this "placeholder", which will be updated? I suppose there might be some "Best practices" or Patterns for caching.</p>
  
  <p>P.S. To magento guys: please don't remind me about Enterprise edition and payed modules.</p>