opencast/annotation-tool

Bug when deleting a scale that is used in a category

dagraf opened this issue · 5 comments

When I delete a scale that is used in a category A and the reload the browser, the category does not properly work as somehow an empty scale seems to be connected to it (see screencast).

Bug.Skalen.loschen.mp4

The question is: Should this even be possible?

And if so, what exactly should happen? I guess the category should just lose its association to the scale and be left without any scale? 🤔

/cc @dagraf

I see two differents solutions:

  1. Deleting of scales that are allready used in a video of the same series (as the actual open video) should not be possible. When clicking on "Löschen" a different modal appears, saying something like: Title: "Deleting of scale not possible"; Text: "This scale is used in at least one category (see list below) and can therefore not be deleted." Below there should be a list of categories that use this scale.
  2. Deleting is possible: Yes. The category should just lose its association to the scale and be left without any scale.

Today we discussed this bug in the OAT meeting.

Behaviour ideals when deleting a scale that is used in category:
(1) prohibit, user needs to remove scale from category first
(2) mark as deleted and
(2a) still show/use with previously associated resources
or
(2b) remove scale from all associated categories
or
(2b) remove scale from own associated categories

User voices:
MH: if scale gets deleted, but category is still in use, this could be problematic
SH: there should be at least a note that the scale is associated with categories
TR: a public scale used in private categories might cause issues upon deletion

Overall, the expected behaviour should include that attention is kept to:

  • existing categories (also those who belong to another user) with previously (before deletion) assigned scales should still work (=> do not break the designed categories of other users), therefore:
  • mark scale as deleted
  • make sure deleted scales cannot be (re-)assigned to categories any longer (select options)
  • unassign scale from all own categories?
  • make sure scale is still associated with all categories of other users (keep attention to model dialog display)?

The list of behavioral items above should be discussed and finalized to address that issue in our work.

The suggested solution regarding the category list could be troublesome: If the scale was public and the user created private categories (not shared with admin/public) with that public scale, admins should not list/see the categories and should not be able to unassign scales from those categories and therefore cannot delete scales

At our institution (Uni Bern), scales are used very rarely. Therefore we do not have a strong opinion on how the behavior should look like. Considering this, here our thoughts:

  • We suggest not to prohibit deleting of scales that are already used in categories. Because we anticipate ending up with (a lot of) scales that can not be deleted, because a user does not take the extra effort to remove scales from all his/her categories.
  • From the described ideal behavior we would prefer (2a) followed by (2b). (2c = remove scale from own associated categories) could be confusing as an admin could think, that in all categories the deleted scale got removed.