Dataflow Activity Parameters Lose Expression and Get Hardcoded After Reopening Pipeline

[svac]

Hi! I’m using a Dataflow Gen2 activity in a Fabric pipeline and passing parameters via dynamic content (pipeline library variables).

When I configure the parameters, they are correctly stored as expressions:

"value": {

"value":

"@pipeline().libraryVariables.Data_engineering_Variable_Library_workspace_id",

"type": "Expression"

}

The pipeline validates and saves successfully. However, when I reopen the pipeline, Fabric rewrites the parameter values as evaluated static string:

"value": "f31c2823-10f1-4e97-bc15-6f39f4981d57",

"type": "String"

This removes the expression and effectively hardcodes the value.

• Is there a supported way to persist dynamic expressions for Dataflow Gen2 parameters in pipeline activities?
• Are there recommended patterns for passing workspaceId/lakehouseId dynamically without the UI flattening expressions?

Thanks!!

[miguel · Accepted solution]

This is currently a known issue that the team is working on to fix. You can check the latest status and more info from the link below:

https://support.fabric.microsoft.com/known-issues/?product=Data%2520Factory&active=true&fixed=true&s... 

[Adityakumar]

Hi @svac,

This looks like two separate things to validate:

1. Whether the Dataflow Gen2 public parameters are configured correctly.
2. Whether the Pipeline UI is preserving the expression metadata after reopening the activity.

Microsoft Learn confirms that Dataflow Gen2 with CI/CD support can expose public parameters and that those parameters can be overridden from a Fabric Pipeline Dataflow activity at runtime.

So the first thing I would verify is:

- The Dataflow is a Dataflow Gen2 with CI/CD support.
- Public parameter mode is enabled.
- The Dataflow was saved after enabling public parameters.
- The pipeline activity is using the parameters discovered from the Dataflow parameters section.

However, if the pipeline JSON initially stores the value as:

"value": {
"value": "@pipeline().libraryVariables.xxx",
"type": "Expression"
}

and after reopening the pipeline it changes to:

"value": "actual-guid",
"type": "String"

then that sounds more like a Pipeline authoring/UI serialization issue than a Dataflow parameter configuration issue.

As a workaround, I would suggest testing the same run through the documented parameterized Dataflow Gen2 pattern and also checking whether the expression is still evaluated correctly at runtime after the UI rewrites it. If runtime behavior is also affected, I would raise this with Microsoft Support because the documented capability is to pass parameter values from the pipeline activity, including dynamic values.

References:

Parameterized Dataflow Gen2 - Microsoft Fabric | Microsoft Learn
Use public parameters in Dataflow Gen2 (Preview) - Microsoft Fabric | Microsoft Learn
Dataflow Gen2 data destinations and managed settings - Microsoft Fabric | Microsoft Learn

I hope this helps clarify the difference between parameter configuration and the possible UI persistence behavior.

[v-abhinavmu]

Hi @svac,

Thanks for reaching out to the Microsoft Fabric Community forum.

Dataflow Gen2 supports overriding public parameters from a Dataflow activity in a Fabric pipeline. To enable this, select Enable parameters to be discovered and overridden for execution, save the dataflow, and publish the parameters. The parameters can then be assigned values using pipeline expressions or variables at runtime.

Could you confirm that you're using Dataflow Gen2 and that the dataflow was saved after enabling public parameters?

For more details, please refer to the below official documentation:

•  Microsoft Learn: Use public parameters in Dataflow Gen2 (Preview) - Microsoft Fabric | Microsoft Learn
•  Fabric Updates Blog: Passing parameter values to refresh a Dataflow Gen... - Microsoft Fabric Community

I hope this helps. Please feel free to reach out if you have any further questions.
Thank you.