I’ve been reading about Drupal theming and preprocess functions and noticed they listed engineName_engine_preprocess & engineName_engine_preprocess_hook in the order of preprocess functions but I’m not entirely sure what the engine layer is? I understand about the core, includes, modules and themes.
Many thanks
The engine is the template engine used. By default Drupal uses the
PHPTemplateengine but you could use other template engines and thus create different preprocess hooks based on the engine type.The template engine is what is used to run the code in the templates. There are different kind of template engines that will allow you to do different stuff with different syntax in your templates, different ways of getting your variables to the template etc. The PHPTemplate uses files ending with
.tpl.php. So all those work because there is some code than can interpreted themRead for more info on PHPTemplate (some old history)