When you are actively working on theming in Drupal, you definitely know how should theme an item list or a table. But, there is a big difference between being able to theme most things in Drupal and really knowing what you are doing and why you are doing it. This is like mathematics. Understanding the logic behind your tools, helps you with creating solutions for problems you've never seen before.
Intended audience
Themers, who already know what they want to do, but do not always know how, and more importantly, do not always know why.
Questions answered by this session
How does the Theming API work under the hood?
How can I use the Theming API the best way?
What is the role if the theme engine in the whole theming process?
What cool stuff can be done using process and preprocess functions and how do they work?
How does the concept of base and sub themes work in the API?
