* Use a single capability 'mod/workshop:exportsubmissions' to control
who is able to export a submission and all associated visible
peer-assessments.
* The export capability is by default granted to teachers and managers
as well.
* Simplify the integration of the export button into the submission
page. There is now a single place where the export button appears - at
the buttom of the submission page.
* Clean up the new strings introduced for this feature.
* Rewrite the portfolio caller class so that it better mimics the
behaviour of the submission.php page. It must not be possible to get
access to contents otherwise not available via the UI.
* Fix phpunit tests.
* Improve behat tests so that they can run in headless browser
(performance).
During the development, some problems were detected in the underlying
portfolio API, especially with LEAP2A format and files collisions
handling. These may be eventually fixed in the future, should there be a
demand for it.
A new capability is introduced to control this, granted to teacher/admin
roles by default: mod/workshop:deletesubmissions. Additionally, students
can delete their own submissions if they are currently able to edit them.
Re-using 'mod/workshop:viewauthornames' would not be a happy option here
because teacher would have to change local overrides every time when
they were closing or re-opening the workshop (if they wanted anonymous
assessment but non-anonymous hall of fame).
Moving stuff from lib.php into static methods in localib.php. Removing
things from workshop core that were implemented in a subplugin. Dropping
stuff related to features not to be implemented in 2.0.
Initial sketches of random allocator. Refactoring of the rest of the
module here and there. Also, this commit removes trailing whitespace and
running empty lines.
