General workflow of plugins

The (shortened) plugins workflow as follow:

• you create the plugin.php file and the index.php

• you then configure where it will be seen (in the plugins section of the administration panel)

• the main/inc/lib/template.lib.php class (around line 140) "loads" the plugins regions

• regions are defined in main/inc/lib/plugin.lib.php and the method "get_installed_plugins_by_region" allows you to know which plugin should be enabled in a specific region of the user interface

• (back to template.lib.php ~140) the template lib "loads" the plugins inside specific template variables called "plugin_[region]"

• the template variables defined are then shown by any .tpl that loads them

  TPL (template) files inside the main/template/default/ directory (see templates section above).

  For example, for the normal student "2-columns" view of the courses list (like in userportal.php), you can check layout/layout_2col.tpl, and in general they will load {{plugin[region]}}variables depending on the region the plugin defines.At the moment, there is no "region" defined for the courses list, so if you want to make a plugin appear there, you should define a new region (both inside one of the .tpl files and inside plugin.lib.php), or you could use the menu_top and menu_bottom respectively (I believe these are for the left/right menu).