How to determine if a node belongs to an existing course

Hi,

If your custom course object extends the CourseObjectNode class, then all you should need is

$course_node = course_get_context();

That should return the course node if the currently viewed node is a part of that course.

If you wanted to find out which course object it belonged to, you could use

$courseObject = course_get_course_object($module, $object_type, $nid);

Where 'module' is your custom course object's module and 'object_type' is the type defined in hook_course_handlers().

Or if you didn't want to use PHP you could try #2324247: Context Integration which exposes course to Context.

You might not need to worry about how to extend classes in PHP. The course_get_context() function'll work outside of class definitions, too (like page hooks, or node view code, or a custom visibility rule callback).

But if you decide to go that route, there's a page in the PHP docs that outlines how to do so (it's a language-level level bit of knowledge, not specific to Drupal): http://php.net/manual/en/language.oop5.inheritance.php

For the Course/Drupal specific bits on defining a custom course object you can look at one of the built-in sub modules like course_book (the CourseObjectBook is an extension of CourseObjectNode).

You could also look at the included course_poll module, which is a very basic extension of a node-based course object.