There are several improvements over what we had before:
1. We track all the questions seen in the the student's previous
quiz attempts, so that when they start a new quiz attempt, they get
questions they have not seen before if possible.
2. When there are no more unseen questions, we start repeating, but
always taking from the questions with the fewest attempts so far.
3. A similar logic is applied with variants within one question.
There is lots of credit to go around here. Oleg Sychev's students Alex
Shkarupa, Sergei Bastrykin and Darya Beda all worked on this over
several years, helping to clarify the problem and shape the best
solution. In the end, their various attempts were rewritten into this
final patch by me.
This parallels question_attempt->minfraction, which allows the
fractional mark to go below zere.
This is needed to allow the certainty-base marking behaviours to work
better.
It was always a bit of a hack to use static methods on the
qbehaviour_whatever classes to return metadata about the behaviour. It
is better design to have real qbehaviour_whatever_type classes to report
that metadata, particularly now that we are planning to add more such.
For example, inheritance works better with real classes. See, for
example, the improvements in
question_engine::get_behaviour_unused_display_options().
This change has been implemented in a backwards-compatbile way. Old
behaviours will continue to work. There will just be some developer debug
output to prompt people to upgrade their code properly.
I think this used to work because mod/forum/lib.php used to be included
everywhere, and in turn included lib/formslib.php. We should declare the
dependencey explicitly.
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.
While doing this, I found various bugs in the manages question types admin page, and so fixed them, and updated the code
there to use $OUTPUT and html_writer.
AMOS BEGIN
MOV [cannotdeletemissingqtype,admin],[cannotdeletemissingqtype,question]
MOV [cannotdeleteqtypeinuse,admin],[cannotdeleteqtypeinuse,question]
MOV [cannotdeleteqtypeneeded,admin],[cannotdeleteqtypeneeded,question]
MOV [deleteqtypeareyousure,admin],[deleteqtypeareyousure,question]
MOV [deleteqtypeareyousuremessage,admin],[deleteqtypeareyousuremessage,question]
MOV [deletingqtype,admin],[deletingqtype,question]
MOV [numquestions,admin],[numquestions,question]
MOV [numquestionsandhidden,admin],[numquestionsandhidden,question]
MOV [qtypedeletefiles,admin],[qtypedeletefiles,question]
MOV [uninstallqtype,admin],[uninstallqtype,question]
AMOS END
