checkExists, create & delete webhookMethods for trigger based nodes (ITriggerFunctions)

wspiral · August 10, 2022, 6:48pm

Describe the issue/question

I created a node (copy/paste) based on RabbitMQTrigger (n8n/RabbitMQTrigger.node.ts at master · n8n-io/n8n · GitHub).

I would like to extend it with the functionality of creating a RabbitMQ queue when the node starts. I found that webhooks have checkExists, create & delete methods which is exactly what I need. How is it possible to get those methods working also for ITriggerFunctions? Or is there any way to define a method in the node that is executed on workflow activation or deactivation?

Thank you.

Information on your n8n setup

n8n version: 0.171.0
Database you’re using (default: SQLite): SQLite
Running n8n with the execution process [own(default), main]: main
Running n8n via [Docker, npm, n8n.cloud, desktop app]: npm

MutedJam · August 11, 2022, 12:55pm

Hey @wspiral, welcome to the community!

Or is there any way to define a method in the node that is executed on workflow activation or deactivation?

Yes, this exists. You can check out some of the other existing trigger nodes, quite a few of them will try registering a webhook when the workflow is activated. For example the Webflow node:

github.com

n8n-io/n8n/blob/master/packages/nodes-base/nodes/Webflow/WebflowTrigger.node.ts#L207-L271


      
          					this,
          					'GET',
          					`/sites/${siteId}/webhooks`,
          				)) as IDataObject[];
          
          				for (const webhook of registeredWebhooks) {
          					if (webhook.url === webhookUrl && webhook.triggerType === event) {
          						webhookData.webhookId = webhook._id;
          						return true;
          					}
          				}
          
          				return false;
          			},
          
          			async create(this: IHookFunctions): Promise<boolean> {
          				const webhookUrl = this.getNodeWebhookUrl('default');
          				const webhookData = this.getWorkflowStaticData('node');
          				const siteId = this.getNodeParameter('site') as string;
          				const event = this.getNodeParameter('event') as string;

This file has been truncated. show original

wspiral · August 11, 2022, 3:21pm

Hello @MutedJam, thank you for your quick response.

Yes, I’ve seen a lot of examples with the webhook implementation but for some reason when I try the exact same thing with the trigger function implementation, it doesn’t work.

sync trigger(this: ITriggerFunctions): Promise<ITriggerResponse> {
}

MutedJam · August 12, 2022, 1:33pm

Hi @wspiral, I am afraid I am not a node builder myself, but perhaps @marcus has an idea?