title: Dynamically change layout and content of website depending on PHP Session variable
body: <p>I am receiving a list of available products and subproducts from a Java webservice and storing it in a session variable.</p>
  
  <p>The products are presented on multiple pages and depending on the availability, some of the main products and their components have to be greyed out (background colors, text color, images changed etc.). In a further usecase they would be completely hidden.</p>
  
  <p>It is an already existing website using php and javascript (no frameworks and cms).</p>
  
  <p>What would be a clean way of altering the content based on the session variable?</p>