[Tagging] Plan Undo framework for taxonomies and tagging

[bradenmacdonald]

Several stories will require an UNDO button, even for fairly complex operations:

• [Tagging] Rename and delete an individual tag #131
• [Tagging] Delete a taxonomy #127
• [Tagging] Bulk delete of multiple tags from Taxonomy Detail Page #130
• [Tagging] Toast Notifications for changes to tags #123
• [Tagging] Remove all tags tool #124 - maybe? not shown in mockups

Acceptance Criteria

• Create a plan for an UNDO framework that can be used by these other stories to implement the undo functionality as shown. Note that undo is only available for at most 5 seconds.

Developer notes

Some options - there may be better ones:

• Use the command pattern for all changes
• Add a "soft-deleted" flag to taxonomies and ObjectTags. On any CRUD action, store the IDs of all the items the user modified most recently.
• It doesn't necessarily have to be on the backend; it could be purely frontend, e.g.:
  • The frontend doesn't actually apply the action until after 5 seconds, but it optimistically "pretends" that it did right away. If the user tries to close the tab during that five seconds, a warning is shown and the change is applied immediately.
  • download enough data to undo the action, then store it in a temporary buffer. If the user clicks undo, use that to apply the opposite change.
• Implement it differently depending on the action