Allow a global search autocomplete of topics and/or list topics across all streams somewhere

[mlncn]

When within a stream, if you type topic: in the search bar it will start listing topics. (Actually, if you type a space (" ") it does an even nicer listing.)

Unfortunately, this does not work in global, cross-stream search: you have to type in the topic precisely (with + instead of spaces) to even search a specific topic, and you cannot see what is available at all.

It would be useful to be able to list (recent) topics across streams in some way, whether through the global (not in a stream context) search or some other way.

[zulipbot]

Hello @zulip/server-search members, this issue was labeled with the "area: search" label, so you may want to check it out!

[timabbott]

@mlncn thanks for the report. I agree this should be better. We have some upcoming work that will significantly improve search typeahead for topics within a stream (currently the frontend doesn't have full topic history available, just recent ones). Doing a global topic typeahead across all history is likely difficult for data/performance reasons; it's potentially a huge amount of data to fetch and collect that's unique for each user.

[wolcen]

Just wanted to mention that I was looking for this same solution, and I noticed that on the recent conversations list, you can filter by topic:

I'm not sure how far back this can go, but for us it does let me find topics all the way back to 2019. This was VERY helpful for me. Given that, as your documentation states "Like your email inbox, Zulip works best if you read it topic-by-topic." - I often find myself looking for topics, rather than having to remember something said about a topic. I'd suggest that highlighting this feature on your https://zulip.com/help/search-for-messages page might be a nice idea. @mlncn does this also handle your use case?

[mlncn]

Using the topic listing from recent conversations when you blank out the main search bar (or blank out and then press "Topics" or type 'topic:' (with the former being a shortcut for the latter) would be a much better entry into it, in my opinion, but yes this is the functionality! Also able to find a topic that had not been added to since 2019.