* Correct sorting in table
* Modify page when nested in exercises
* Fix links between pages
* Link from statistics page to programming_groups/index
* Link from submission page to programming_groups/<id>
* Allow filtering for exercise ID on ProgrammingGroup#index
* Add search fields for internal and external user id on pg/index
For the submission and comments, I mainly decided to use a `has_one` association. Based on the database schema, multiple request for comments could be allowed (i.e., for each file or submission), but this won't happen practically (since we always create new submissions and files). Hence, the `has_one` association is representing our relationship better.
This change allows us to use the session ID immediately for the connection_change and connection_status methods. Hence, we can identify different browser sessions of the same user.
Previously, we were at an ACE editor published between 1.1.8 and 1.1.9. This caused multiple issues and was especially a problem for the upcoming pair programming feature. Further, updating ace is a long-time priority, see https://github.com/openHPI/codeocean/issues/250.
Now, we are not yet updating to the latest version, but rather to the next minor version. This already contains breaking changes, and we are currently interested to keep the number of changes as low as possible. Further updating ACE might be still a future task.
The new ACE version 1.2.0 is taken from this tag: https://github.com/ajaxorg/ace-builds/releases/tag/v1.2.0.
We are using the src build (not minified, not in the noconflict version), since the same was used before as well.
Further, we need to change our migration for storing editor events. Since the table is not yet used (in production), we also update the enum.
* This commit refactors the table used to store events.
* We also use a UUID as session identifier in the synchronized editor to support multiple concurrent tabs opened by the same user.
* Further, we renamed some methods to make them easier to distinguish.
* We want to identify a user that has triggered a testrun. Previously (in regular operation), only submission author who were regular users were able to start a testrun. Now, we want to prepare a future where submission authors are programming groups. Still, a testrun is triggered by an individual user and not a group.
* Further, this commit fixes some missing foreign key constrains.
With these changes, the newly created StructuredError will have all StructuredErrorAttributes preloaded, thus speeding up further access to this association.
