How to add correlation of Parent and sub flow in Elsa Studio

[MannojKumarCh]

Hello Below is my workflow image

I have the workflow of leave approval with 4 to 5 levels

Level 1 - Apply Leave
Level 2 - Manager Approves Leave
Level 3 - If Manager miss to approve leave, it escalates to super manager
Level 4 - If Super manager miss to approve leave it escalates to HR Manager

In my workflow I have Leave application as Http end point trigger and next in the flow I have another Http end point for Leave Approval

When 2 leave applications are open, workflow is not able to relate the Leave Approval request to corresponding Application and it fails as ambiguous

How can the correlation be made for the child/sub flow to the parent flow?

I am using Elsa.ServerAStudio project in elsa-core 3.5.3

Any support here will be of great help

[sfmskywalker]

Short answer: use workflow correlation for this.

What the current HTTP module does is:

• it reads a correlation ID from either the X-Correlation-ID header or the correlationId query-string parameter (elsa-core/src/modules/Elsa.Http/Selectors/HeaderHttpCorrelationIdSelector.cs and .../QueryStringHttpCorrelationIdSelector.cs),
• then HttpWorkflowsMiddleware includes that correlation ID when it looks up bookmarks to resume (elsa-core/src/modules/Elsa.Http/Middleware/HttpWorkflowsMiddleware.cs).

So when you have multiple leave requests in flight, the normal pattern is:

1. Generate a business correlation ID for the leave request.
2. Set that on the workflow early, e.g. with the Correlate activity (elsa-core/src/modules/Elsa.Workflows.Core/Activities/Correlate.cs).
3. Include the same correlation ID on the approval HTTP call, either as X-Correlation-ID or ?correlationId=....

That way the resume lookup is no longer ambiguous, because the bookmark lookup is filtered by the correlation ID as well as the HTTP route/method hash.

So I would not model this as “parent/subflow correlation in Studio” first. I would model it as “set and pass a stable correlation ID per leave request”.