How to persist a value related to a webhook node during its execution

Questions
1

I’m creating a custom webhook node and facing to some challenges on how I should deal with the flow within the webhook function.

It’s a microsoft sharepoint webhook node, the notifications behavior is described here Overview of SharePoint webhooks | Microsoft Docs

There is an additional step after getting events from the webhook, I have to grab manually what has changed in the targeted resource, that should return an array of change events.

What I want to do now is to store the value of a marker provided by the last execution of this retrieval so that the next time I retrieve the dataset it will ignore all entries before the marker.

Is there a built-in feature to implement such a flow?

thanks

2

Welcome to the community @irzhywau!

If the data you are storing is very small you can use getWorkflowStaticData as for example here:

I hope that helps!

3

thanks for your quick reply @jan
I already use it in webhookMethods.default.checkExists and webhookMethods.default.create, but I could not make it work within webhook function.

I tried something like this, I checked in database but the value has not been stored

const workflowData = this.getWorkflowStaticData('node');
workflowData.lastChangeToken = "a string here"
4

That is strange. It should work. Does the workflow run successfully?

5

Ah also important to mention that it only gets saved to the database if you run in production-mode and not if you run it manually via the editor-UI.

6

yes, workflow succeeds
what do you mean by manually via editor-UI, webhook Test Mode?

anyway for both it’s not stored, I explictly activated the workflow to have it in production mode. Still same result.

What is the flow behind webhookData.<some-property> = value, where can I find it.
I just noticed that this statement seems working like a charm within webhookMethods functions but not in webhook implementation

PS. I’m quite new with n8n

7

So you activated the workflow and you used the production webhook and it did still not save it?

What do you mean with what is the flow behind it?

8

exact!

I’d just like to know wether the scope of execution of this statement matters. I noticed that in the webhook method this is as IWebhookFunctions and in webhooks.<name>.<method> it’s a IHookFunctions

So now I’m wondering if the concrete object returned by this.getWorkflowStaticData('node') on both scopes are the same. I don’t even know if that make sense actually.

Anyway here is the code:


async webhook(this: IWebhookFunctions): Promise<IWebhookResponseData> {
		const credentials = this.getCredentials(credentialName);
		if (credentials === undefined) {
			throw new Error('No credentials got returned!');
		}

		const webhookData = this.getWorkflowStaticData('node') as IDataObject;
		const listEvents = await customApi.retrieveListEvent();

        if (listEvents.length > 0) {
             // the issue is that the value I set here is not persiting
             webhookData.lastChangeToken = listEvents.pop().ChangeToken.StringValue as string
        }

       // ... return statement
}
9

@jan I’m wondering if I shouldn’t call a workflow save here to persist what has changed in webhookData. Is there a common way to do that witin this webhook function scope?

10

Sorry @irzhywau had to do some testing and check the code. You are right there was a bug and it did not get saved. I just fixed it and will release it with the next version. Will update here once released.

11

ah that’s good news, thanks for further checking this.
Is there a branch with the fix I can see?

12

No problem. Is simply in master.

13

thanks @jan for your valuable help

14

Got released with [email protected]

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