I had the privilege of attending DrupalCamp London on the weekend of March 2nd and 3rd. I wasn't really sure what to expect but was hoping it would be like a mini DrupalCon.
You may be used to adding validation functions for an entire form, but what if you just want to validate an individual form element? Do you really need a form wide validation function for a single field?
You hit a URL and Drupal gives you a page back. Magic! But perhaps you are wondering, what is Drupal doing under the hood? You know that putting it down to magic is not going to help you to create your own custom modules.