Admin - exercise editor

[achirkin]

We need to enhance and polish scenario (a.k.a. workshop, a.k.a exercise) editor to support new settings. Currently, it is located at Handler.Mooc.Admin.ScenarioEditor.

• Rename all occurrences of the thing to "Exercise editor" (not scenario and not workshop), make it a nice and RESTfull :)
• Add a table ExerciseSettings with key and value columns, same as UserProps. I think it is worth doing so to make it easy to add new settings in future. scale and canAddDelete fields should migrate to that table as keys.
• Add GUI to set canAddDelete and canModifyProperties to exercise editor (pls, check correct names in qua-types)
• Allow to replace geometry and image and description in the exercise editor
• Add a new editable setting: customizable user html message to show student upon successful submission. it should also support two placeholders using ${abc} syntax to insert user id or some other user or exercise related info (userId for sure, something else TBD).

Maybe it makes sense to minimize "create exercise" form in favor of maximizing flexibility of "modify exercise" page to avoid code and functionality duplication. Though, this is up to you :)

[mb21]

Add a table ExerciseSettings with key and value columns, same as UserProps.

I'm not sure it's easier to deal with the untyped key-value pairs and self-joins instead of simply adding some columns to the Exercise table. Performance impact should be negligible (especially since we already have image and geometry columns).

[achirkin]

It's not about performance for me, but rather to be able easily extend it by adding more and more properties. And we still need to keep old DB records, which would have to be migrated.

[mb21]

ok, if you think its easier to extend like that...
(the old DB records would just get NULL in the new columns)