Well, I've finished doing the class diagram for the plugin I developed for Moodle:

Explanations

Previously in moodle existed a class called Moodleform. This class is intended to be subclassed, as it works as a template for all forms in Moodle. So I subclassed it in order to make my own form for OpenSyllabus plugin. The functions (all their sequence diagrams will be posted in my next post) I needed to redefine were:

1. definition(): this operation is called by the constructor and builds the form with the fields you define on it
2. definition_after_data: for making some validations or instructions after data is submitted.
3. getFileValue(): this operation retrieves the name of the uploaded file.
4. validation(): this operation makes some validations before the form is accepted. In my case, as I only had to make a prototype, I redefined it empty.
5. add_action_buttons(): adds the "submit" and cancel buttons to the form.

As I said, I will provide sequence diagrams later. Once I defined the form, now only we must bind this form to our Main process and the logics of our problem is finished. It's easy to understand, it isn't?