This commit implements the qbank api so that any plugin
can implement its own question bank. This api currently
works parallely with the moodle core classes and the
added qbank in the core, means the moment a plugin
is installed, that object is replaced with the object
from the plugin instead of core, which means the api
has flexibility till the plugins are integrated and the
plugins can be integrated in any order.
All the old classes are still there and not deprecated
as there is a different tracker for the changes to the
quiz and another tracker for class deprecation and
class renaming. Core question units tests are pointing
to the new api structure but the classes are pointing
to the location related to the plugin availability.
Co-Authored-By: Luca Bösch <luca.boesch@bfh.ch>
Co-Authored-By: Guillermo Gomez Arias <guillermogomez@catalyst-au.net>
one more array fix
Added an upgrade step to remove duplicate stamps, added a unique index
on (contextid, stamp) and modified the question_category edit code such
that stamp duplication in the same context is not permitted.
1. Autosave works in some ways just like a normal save. We ultimately
call $behaviour->process_save() to do the work, and create a new step to
hold the data.
2. However, we come in through a completely different route through the
API, starting with separate auto-save methods. This keeps the auto-save
changes mostly separate, and so reduced the chance of breaking existing
working code.
3. When the time comes to store the auto-save step in the database, we
save it using a negative sequence number.
This is a clever trick that not only distinguises these steps, but also
avoids unique key errors when an auto-save and a real action happen
simultaneously. (There are unit tests for these tricky edge cases.)
4. When we load the data back from the database, most of the time the
auto-save steps are loaded back as if they were a real save, and so the
auto-saved data is used when the question is then rendered.
5. However, before we process another action, we remove the auto-saved
step, so it does not appear in the final history.