Add attachment support

[williln]

It would be nice to be able to use the attachments feature in Slack messages to format the message.

Link to code in Slacker for reference
Link to Slack API for reference

One bug I ran into when just forking the connector is that the current Message class doesn't support passing an extra argument, like attachments, to the respond() method and there's not currently a message attribute that looks like it could be used for that.

[NMC-DAVE]

So williln,
Do you successed to send attachments? I want to send images to slack.
Is there any clues? Very thanks!
Dave

[williln]

@NMC-DAVE I did not. As far as I can tell, Opsdroid isn't yet configured to allow for sending the arguments that the Slack API needs to do special formatting or to pass files/images. Sorry!

[jacobtomlinson]

@williln and @NMC-DAVE I am looking to merge this ocnnector and a few others into the core of opsdroid in opsdroid/opsdroid#530. I will explore adding this functionality once I've done that.

[kim0]

@jacobtomlinson Seems like slack connector was merged in Apr (Thank!) .. Any status update please for adding attachment support. I'm contemplating to use opsdroid, and that's one piece of functionality I would love to have! Thanks for good job on opsdroid!

[jacobtomlinson]

@kim0 Slack has always been supported. In April it got merged into opsdroid as a core connector instead of a plugin. There still isn't support for other message types, but it's high on my priority list.