Course configuration validation does not accept model solutions in LTI exercises

[markkuriekkinen]

If a course defines an LTI exercise in a config.yaml file and adds the field model_files in config.yaml, then gitmanager does not accept the configuration as valid and the build fails.

I think LTI exercises should enable the possibility for model solutions. The A+ feature for model solutions doesn't really have anything to do with LTI exercises and they shouldn't interfere each other.

LTIExercise validator doesn't include model_files, though neither does the parent class Exercise (links below). Now I'm not sure how even the normal exercise can be missing this.

• gitmanager/access/course.py

  Line 263 in f9cfecb

  class LTIExercise(Exercise):

• gitmanager/access/course.py

  Line 160 in f9cfecb

  class Exercise(Item):

[lainets]

The model_files are currently only on the exercise specific config files instead of the index.yaml because (I think) that is how it worked previously. The same applies to template_files. They should, at least in theory, work for LTI exercises as well as long as they are specified in the exercise config file instead of the index.yaml file.

It would make sense to just move the fields to the Exercise class, and then copy the field content from the exercise config if it exists there but not in the index.yaml file.