Use attachments to compensate for lack of reaction emoji across Slack bridges

[patcon]

This is a stretch, but I'm just thinking on how to use the existing feature sets to work around API and permissions limitations.

Attachments can be updated after the fact: https://api.slack.com/methods/chat.postMessage

Attachments can be very subtle and small, when configured correctly. You can experiment here: https://api.slack.com/docs/messages/builder

I wonder if the attachment could be used to build a little representation of the emoji counts across Slacks...

[patcon]

Been thinking on this one. Here's a little demo of all the appropriate formatting we could get:

Playable demo

Was trying to find a combination of brackets and spaces and numbers that made this look like buttons, but without the confusion of actually being clickable. A handy list of bracket types.

[patcon]

My two favourites, but I think I like the small ones that only use the footer key most

footer

actions buttons

[patcon]

So here's my thinking:

• use the non-button footer field
• as example, assuming #foo and #bar slack channels
• when message first posted, no attachment
• if someone in #foo posts a message and someone in #bar adds the 👍 emoji, an identical attachment will be added to each message, with "👍 1"
• this will seem redundant for the person who clicked, but it will be clear that the tally is a sum
• if someone in #foo clicks :+1: reaction as well, the attachment on both ends will update to ":+1: 2"
• removing a reaction emoji will decrement the tally
• if the bridge has been restarted and the connecting message ID is gone, then we just discard the reaction. This is a bummer, but all we can do without a messy solution. (This messy solution could involve API calls to the search endpoint to rebuild the connection of message IDs).

pros: can see reactions across bridges. no need to visit other channel/team to see how people respond. (I'm finding this desire to see responses is felt very strongly -- Since my bridged channels are on the same slace doing translation between channels, I can easily visit other channels to see if an idea resonated. Seems bad that most people lose this feedback.)

cons: still can't see who left the reactions. slight duplication in UI.

Alternatives: could avoid showing on the reaction-giving end, and so users could just tally up the totals. But I think this will confuse people who see two different numbers. not everyone even know about the bridge. but with the sum method, then as soon as they leave their first reaction, they see the attachment increment, and they understand what's happening.

[patcon]

Another con: people could vote on each bridge, to get as many votes as bridges, and this might not be apparent. For example, when emoji used to vote. But at least someone could investigate and see on each bridge by inspecting the actual reaction emoji widget (which shows who voted on hover)

[patcon]

One big con that I somehow neglected: An attachment can never be added to the original message, since it's not owned by the bot. So it will just be other places that benefit from seeing the full extent of reactions

[patcon]

An attachment can never be added to the original message

Just realized that, if we want, we could get around this by immediately echoing back a blank reply message with attachment (either threaded or not), which can be used as a container for emoji replies from across the gateway.

Sample

[patcon]

Got a simple PoC working for this, will come back to it later: https://github.com/patcon/matterbridge/compare/805d84e...526-reactions

Currently just appends emoji to end of existing messages, but should really:

1. check to see if special reaction emoji attachment is present as first attachment on reaction target.
2. If yes, parse it to get counts of emoji, then add the current one.
3. If not, create and attach
4. post update to message, updating attachment

[patcon]

Just a note that zulip also seems to support reactions: https://zulipchat.com/api/real-time-events

[Divide-By-0]

Got a simple PoC working for this, will come back to it later: patcon/matterbridge@805d84e...526-reactions

Currently just appends emoji to end of existing messages, but should really:

1. check to see if special reaction emoji attachment is present as first attachment on reaction target.
2. If yes, parse it to get counts of emoji, then add the current one.
3. If not, create and attach
4. post update to message, updating attachment

This is cool! Can we enable it on slack <> discord so that reactions can be transferred between the two?