This implements the page showing the table. It is not yet integrated into the tab bar. To try this, go to an Assign roles page (one with URL .../admin/roles/assign.php?contextid=...) and change the 'assign' to 'explain'.
* New table role_context_levels
* Populate table with defaults on install
* Populate table on upgrade with the same defaults, plus any additional ones needed to ensure all the role assignments already in the database are allowed.
* Change get_assignable_roles to respect these settings.
* UI for these settings on the add/edit role form.
* Save these settings when a role definition is saved.
* If in a context, there are no roles you can assign, display a polite message.
* Back up these settings.
* Restore these settings. When resotring a <=1.9.x backup file, any newly imported roles are set to be assignable at all contextlevels.
Restore not tested because it is broken in HEAD.
Including:
MDL-11529 When assigning/overriding roles, the dropdown for switching to another role should have a number in brackets
MDL-16549 Should not be able to edit the permission associated with moodle/site:doanything on any role.
* Make the role being assigned clear in the title
* Make the options in the middle of the page be in a collapsable options section, collapsed by default.
* Put them in a smaller font too.
* Switch the date selectors here to use a shorter date format, and change 'Course start date' to 'Course start'.
At the same time, I took the opportunity to try to work on some of the usability issues on this page. Note that I have not quite finished! So don't comment until tomorrow.
In the course of doing this, I also did: half of
MDL-11529 Show the number of assignees of each role in the change role dropdown on this page.
MDL-17067 Make it clear in the UI that admins are not allowed to unassign themselves.
To do this, I found a way to clean up the method signatures of a couple of accesslib methods, so I did, hence the fact that this seems to touch some unrelated files.
Also, there is a nice new method in accesslib get_context_url, which gives you the natural URL for a context, so the course view page, or the user profile, etc.
I have not copied and pasted the same code into lots of different places. That sucks. We really need to refactor this into a function that builds the navigation up to, and including the user's name. However, I don't have time now. A list of the places touched by this bug (MDL-12373) will at least give a complete list of places that such a refactoring would have to touch.
Improvements to the tabs for assigning and overriding roles. MDL-12120
Tabs are now all on the top row
Tabs have clearer titles
Other help texts improved
