Hey @david, sorry for the delayed response.
If you see value in supporting the ability to create a filter with multiple tags in one command, I might suggest this syntax instead though, which more closely matches how things are displayed:
/discourse watch some-category tags:foo,bar,baz
One way to think about the current implementation is that a given tuple
(category, tag) can only have one status associated with it from the following set:
(watching, following, muted, nil). And a user can only modify a single tuple at a time. (This is where the “it tries to work out how to augment the existing rules” comes in. But I don’t think it’s actually too difficult to reason about from the user’s perspective).
To make things simpler, the Slack command UX currently only allows you to create or update filters where category or tag is nil. But thinking about it more now, I don’t think it would be too difficult or add too much additional complexity to support the combination of category/tag filters in the current design.
That said, I’m not attached to it if you find that the design you’re currently exploring is the way things should go.
I would recommend exploring this a bit more since I agree that seems like the biggest change in your new design. See if you can think of likely ways that people may end up with filters that have overlapping matches and what, if anything, the plugin should do to try to help there.
You might also want to take a peek at the code for the plugin as it exists in my current fork as I think the implementation for the rule augmentation has been simplified quite a bit, but this pull request is still pending.