Re-implement attachment support

[paulhammond]

The latest version of the hubot adapter fixes many things. But, there was one big regression, which is that we no longer support attachments (as originally implemented in #32).

The RTM API used by hubot-slack doesn't currently support attachments, so fixing this requires some server side changes at Slack. I'm opening this issue here so everyone knows this is something we want to fix.

[tshedor]

Ahhh, good. Thought I was going mad.

It's horribly janky, but we got around this today with an Incoming Webhook. Is there a more advisable method or is that presently best solution?

[dblandin]

If attachment support is broken in the current release, then I think that the docs/attachements.md file should be updated or removed.

I was about to update a script to use attachments, following that documentation, when I found this issue.

[paulhammond]

@dblandin Thanks for pointing that out! I just removed the doc in 4693ccd.

[inkel]

Thought I was going mad.

You were not the only one!

It's horribly janky, but we got around this today with an Incoming Webhook

I think I might have to resort to the same solution. Not the prettiest one, I think, but it's something.

[inkel]

If it helps anyone, I've added a scripts/slack-attachment.coffee script that restores emitting slack-attachment events using an Incoming Webhook:

# Description:
#   Enable again the 'slack-attachment' event
#
# Environment:
#   HUBOT_SLACK_INCOMING_WEBHOOK

module.exports = (robot) ->
  getChannel = (msg) ->
    if msg.room == msg.user.name
      "@#{msg.room}"
    else
      "##{msg.room}"

  getUsername = (data) ->
    data.username || robot.name

  attachment = (data) ->
    payload = data.content

    payload.channel  = data.channel || getChannel data.message
    payload.username = getUsername data

    if data.icon_emoji?
      payload.icon_emoji = data.icon_emoji

    reqbody = JSON.stringify(payload)

    robot.http(process.env.HUBOT_SLACK_INCOMING_WEBHOOK)
      .header("Content-Type", "application/json")
      .post(reqbody) (err, res, body) ->
        return if res.statusCode == 200

        robot.logger.error "Error!", res.statusCode, body

  robot.on "slack-attachment", (data) ->
    robot.logger.warning "Using deprecated event 'slack-attachment'"
    attachment data

  robot.on "slack.attachment", (data) ->
    attachment data

It's far from perfect but does the trick for the time being. I might release it as a package later.

[tshedor]

@inkel Bomb. Thanks, that's a lot more concise than our patchwork.

[inkel]

@tshedor my pleasure!

[inkel]

I've made it a package, in case someone else needs it: https://www.npmjs.com/package/hubot-slack-attachment.

[lilyball]

Speaking of attachments, the other thing the RTM API is missing that webhooks have is the ability to post using a different username. This is something I use in an incoming webhook and I would love to rewrite my webhook as a Hubot script.

[inkel]

@kballard in the package I made if you create your payload like the following:

payload =
  username: "neo"
  # … continue as before

you could override the username used by the incoming webhook. It isn't the best solution but it works. The only caveat I've found is that if the username sent is the same as an existing username it will be displayed as neo (bot), following the username provided in the previous example.

[lilyball]

@inkel I suppose I could use your package just for the username support. Though I need icon url support too, so either I'll have to submit a PR, or just write my own package.

[inkel]

@kballard I've implemented basic icon_emoji support in the same way, that is, adding a icon_emoji parameter with the code for one of Slack's emoji (for instance: payload.icon_emoji = ":smiley_cat:",) however support for icon_url isn't implemented yet. I'll gladly accept a pull request, or implement it later in the day when I got the time.

[inkel]

Thanks to @kballard the script is now as feature complete as I could wish for a 1.0.0 release. It's already published in npm, so update your hubot's package.json to the new version.

[paulhammond]

The server side changes are now almost done, and I've just pushed #148 with a provisional implementation in slack-hubot... comments on the pull request are welcome

[paulhammond]

#148 is now merged, and we just released v3.3.0, so I think this is fixed!

[dblandin]

🎉🎉🎉