Add tags for datasets

[fm3]

Adding a tag system to Datasets, analogous to what Annotations already have.

URL of deployed dev instance (used for testing):

• https://datasettags.webknossos.xyz

Backend Changes

• Dataset json now contains additional field tags (list of string)
• Dataset update route now expects tags as well (it being missing will be interpreted as empty list), changes tags in database

Steps to test:

• Open the dataset table. There should be a new row for tags.
• Try adding some tags for a few datasets.
• Clicking on one of the tags should add the tag to the search and hide all datasets that do not have this tag.
• The clicked tag should appear on the top left of the dataset table.
• Clicking on close on the list of tags the datasets are filtered for, should remove that tag from the filtering
• Reloading the page should preserve the filtered tags.
• Adding or removing a tag from a dataset, then waiting a second for the backend call and then reloading the whole page, should show the dataset with the added/removed tag.
• Reloading a dataset should also not change the displayed tags of a dataset.

Issues:

• fixes Organization of datasets with tags #5829

---

• Updated (unreleased) changelog
• Updated (unreleased) migration guide if applicable
• Ready for review

[fm3]

@MichaelBuessemeyer The backend part should be done. I could only test it in a limited way so far, as there is no frontend yet. If you encounter problems, feel free to ping me :)

[jstriebel]

Backend mostly LGTM, please see my two comments @fm3:

[jstriebel]

We could also use the json or jsonb type (seems like it's available from pg 9.6). It's also possible to create indices on jsonb columns and query them efficiently (e.g. when searching/selecting by tag):

https://www.postgresql.org/docs/9.4/datatype-json.html#JSON-INDEXING

[jstriebel]

But also totally fine as-is for now I guess.

[philippotto]

The front-end code looks great 👍 However, I think that I've found a potential race condition (see my comment).

Other than that, I have some UI suggestions:

• turn the cursor into a pointer when hovering the tags (via CSS)
• show a tooltip which explains the tag interactions (e.g., "Click to only show datasets with this tag", "Add a new tag", "Remove this tag from this dataset")

Would be great if you could generalize these UI improvements so that the tags for the explorative annotations also profit from these :)

[philippotto]

If I change the tags for two datasets and don't wait for the first update to be finished, the second update will get lost then, right? I think, a clean solution would be to have some sort of "mutex promise" which is either null (then, one can execute the update) or it's a promise which needs to be awaited. Also, maybe not the entire function needs to block on that promise (but instead only the await updateDataset part maybe?).

[MichaelBuessemeyer]

Thanks for spotting this. I implemented a queueing like behaviour for all updates on the same dataset. This queuing ensures that each previous request is finished before the current request starts. Therefore it is ensured that the backend always gets the updates in the correct order. Thus no update call that (by network magic) was faster at the server gets lost because a slower update request that is much slower overwrites its changes afterwards.
Here is a screenshot of a few dataset changes made on a single dataset in a row by changing the tags of a single dataset. The connection is throttled very strongly to test this corner case. The graph on the right illustrates that one call only starts after the previous updates finished.

[philippotto]

Great, looks merge-ready to me :)

[MichaelBuessemeyer]

Is it correct, that I had to adjust the version of the tools/postgres/schema.sql manually?

If yes, hopefully the CI works now 😅