Can a plugin add a webhook?


#1

I’m working on a plugin that communicates with an external web app. The web app is also informed of changes in Discourse through the use of webhooks.
Right now, installing the plugin is complicated, because it requires to also manually set up the webhooks. Is there a way my plugin could set up the webhooks itself?


(Jay Pfaffman) #2

I’m not much of a plugin author, but I’m pretty sure that you can call something like

hook = WebHook.new(payload_url: "https://sefsdf", secret: "lkjlkjlkj", active: true)
hook.save

Here are the other things in a webhook that you may or may not need to set.

 id: nil,
 payload_url: nil,
 content_type: 1,
 last_delivery_status: 1,
 status: 1,
 secret: "",
 wildcard_web_hook: false,
 verify_certificate: true,
 active: false,
 created_at: nil,
 updated_at: nil>

(Alan Tan) #3

Ah that would only create a web hook record in the database but doesn’t enqueue any jobs.

What kind of custom fields/webhook are you sending to your web app? You could subscribe to certain DiscourseEvents and add a custom Sidekiq job which calls an API on your web app.


#4

Thanks @tgxworld. I’ve seen examples of how to use DiscourseEvents to emulate Discourse native webhooks here and here. I will try to do that if there’s no other choice.

But this seems complex. I would love to have a one-liner, like what @pfaffman proposed. When you use the UI or the API to create a webhook, doesn’t Discourse call an internal function I could also use from my plugin.rb file?


#5

Is this a call to the kind of internal function I’ve just mentioned?


(Erick Guan) #6

If you want to invoke a webhook when certain internal event happens, here it is the example. GitHub - fantasticfears/discourse-user-created-webhook.
If you want to add a new type of webhook, here it is the example. GitHub - fantasticfears/discourse-webhooks-example


#7

Thanks a lot @fantasticfears, I will try this.


#8

Here is what I did eventually:

Since I need standard notifications for topic creation and deletion, I figured out Discourse already enqueues those, as part of the standard webhook feature. So there’s no need to do it myself.

What remains to be done, as @pfaffman suggested, is to add the webhook to the database. However, the proposed code fails silently, probably because of missing and/or incorrect parameters.

Here is my full working code:

#plugin.rb

# Add our webhook automatically, so that admin doesn't have to do it manually
after_initialize do
	# Delete our previously installed webhook (reserved id = 1000)
	WebHook.where(id: 1000).destroy_all

	# Create the webhook (reserved id = 1000)
	hook = WebHook.new(
		id: 1000,							# Our reserved id						
		payload_url: 'https://hfzeoihifzh/',
		content_type: 1,					# 1 = 'application/json'
		secret: "min12characters",
		active: true,
		verify_certificate: true,
		web_hook_event_type_ids: [1]		# 1 = topic events
	)
	hook.save	
end