Botkit: @users and #channels not linked

[bahlo]

Botkit: 0.0.8
Node: v5.7.0
OS X: 10.11.3

I'm having trouble with linked names and I'm pretty sure, it's an oversight on my side.
Using bot.say() like the following posts the message, but doesn't link names:

bot.say({
  text:       message,
  channel:    generalID,
  link_names: 1
});

What am I doing wrong?

[dossy]

What are the contents of message? Have you read https://api.slack.com/docs/formatting#linking_to_channels_and_users ?

[bahlo]

Yes, I have and I've also read Parsing modes.
The content of message is something like: Hello @username, welcome to #general.
You append the attributes link_names or parse here, but it doesn't seem to work.

[dossy]

From parsing modes:

By default, Slack will not linkify channel names (starting with a '#') and usernames (starting with an '@'). You can enable this behavior by passing link_names=1 as an argument. This behavior is always enabled in parse=full mode (see below).

On the previous line of Slackbot_worker.js that you linked to:

            parse: message.parse || null,

Looking at the chat.postMessage API documentation:

parse full Optional
Change how messages are treated. Defaults to none. See below.

So, if you want link_names to function, you have to also set parse=full.

[bahlo]

I tried using link_names=1 and parse=full, but that didn't work :cry:
I'll try again and report back :ok_hand:

[dossy]

Yeah, to be honest I never tried to get the link_names=1 functionality working, I use the control sequence method of linking to users and channels (e.g., <@U1234ABCD> and <#C1234ABCD>) which has worked for me.

[bahlo]

That's how I got it working - but automatic linking would be much nicer.

[dossy]

Okay, after doing some digging, I now understand a few things about the Slack API and Botkit that explains what we're seeing:

1) The Slack RTM API doesn't understand link_names.

At least, that's what's suggested by this error in the Message Builder:

2) The Slack Web API should understand link_names, since the documentation for chat.postMessage documents it.

3) Botkit sends messages to Slack using the RTM API, unless certain features are specified in the message being sent (see lines 303-308 of Slackbot_worker.js):

        /**
         * These options are not supported by the RTM
         * so if they are specified, we use the web API to send messages.
         */
        if (message.attachments || message.icon_emoji ||
            message.username || message.icon_url) {

4) bot.reply() is convenient, but annoying.

It does not pass the full message object that you give it as its first parameter to bot.say() -- instead, it creates a new msg object and populates msg.channel and msg.text to it, _unless_ you pass a non-string type value as the second paramter resp. This has the unfortunate side effect of making something like this not work as one might expect:

   var msg = {
       'link_names': 1,
       'parse': 'full',
       'channel': message.channel
   };
   bot.reply(msg, 'Here is my reply, @dossy.');

In theory, you could work around it like so:

   var msg = {
       'link_names': 1,
       'parse': 'full',
       'text': 'Here is my reply, @dossy.'
   };
   bot.reply({ 'channel': message.channel }, msg);

_Except_ for what I learned in parts 1-3 above. As is, Botkit will send the above example through as a RTM API call, and the link_names will be ignored. I suppose we should submit a PR to include parse and link_names to the conditional that makes Botkit use the Web API, but for now you can kinda work around it by sending an empty attachments array, like so:

   var msg = {
       'link_names': 1,
       'parse': 'full',
       'text': 'Here is my reply, @dossy.',
       'attachments': []
   };
   bot.reply({ 'channel': message.channel }, msg);

I tested this and it worked for me. I just wanted to at least prove that there _was_ a way to get the link_names functionality to actually work and that this wasn't a Slack documentation error, but rather a Botkit issue.

[bahlo]

Awesome, thanks for the descriptive answer. Great work! :+1:

I'll use an empty attachments array for now, maybe it's a good idea to make the difference between the RTM API and Web API more clear in documentation?

[dossy]

Ideally, the underlying plumbing (whether it's RTM or Web) should be abstracted away from the developer who uses Botkit - the issue is really with Botkit needing to force use of the Web API in more cases, like when parse and link_names are passed, basically extending that if condition in Slackbot_worker.js.

Glad we were able to work this out, though. It definitely had me puzzled.

[techinpark]

link_names is deprecated use <@UDNSKZCOC> for user tagging.
https://api.slack.com/docs/formatting#linking_to_channels_and_users