Vis ikke fejl ved sletning af aktiviteter med inviterede

[rasmusselsmark]

Løser #1040 (se skærmbillede med fejl på ticket)

Bemærk at pga. Django, vil der stadig stå at aktiviteten blev slettet, selvom den i realiteten ikke blev slettet:

Det lader dog til at være en "feature" i Django, som vi ikke umiddelbart kan gøre noget ved.

Har valideret lokalt at man godt kan slette aktiviteter uden invitationer.

[what-the-diff]

PR Summary

• Updating Activity Administration Functions

  • The code for managing activities has been enhanced to include functions related to deletion like delete_queryset and delete_model. Now, when an activity is deleted, success or error messages are showcased, ensuring the process is more intuitive and user-friendly.

• Migration to Alter ActivityInvite

  • The system behavior when an activity is deleted has been changed. Previously, all associated invites were also deleted (CASCADE) but the new change ensures that invites are unaffected (DO_NOTHING) when the parent activity is deleted. This alteration was established through a migration in the 0056_alter_activityinvite_activity.py file.

• Counting Related Activity Invites and Protecting Linked Data

  • A new function, invitations, has been added to the activity.py script that counts the invitations of an activity. This addition helps provide a quantitative view of an activity's reach. Furthermore, to prevent disruption and potential data inconsistency, the activity's delete method has been overridden. It now prevents deletion of an activity if there are still participants or invites, offering an error message if attempted.

• Preservation of Activity Invitations

  • To coincide with the above changes, the model for activity invites (activityinvite.py) has had its treatment of the activity foreign key updated. Similarly to the previous point, the on_delete option has been modified from CASCADE to DO_NOTHING, ensuring activity invitations are preserved even if the activity itself is deleted.