Power Automate - Call child flow with custom value dynamically

[santoGD]

Hi All,

I have a requirement to call child flow dynamically based on workflow id .

I have more than 50 child flows and these child flows need to be called from a generic parent flow based on some values.

I have the flow names and the workflow id in a table and I need to call the child flows based on passing that id in the custom value.

Thanks in Advance

Santo

[David_MA]

Have you tried populating the Child Flow field using the Enter a custom value option?

If not, I would try that to see if it works. I haven't found a use case for that option, so this isn't something I have tried. If I need to call a flow, I choose it from the menu.

[santoGD]

Hi @David_MA 

Thanks for the update.

I have tried using the custom value option but it is showing error while saving the flow.

The output is the workflow id from the process table.

Please help if there is any way to call it via custom option.

Thanks

Santo

[Chriddle]

A "Cusom value" has to be the id of the child flow.

There is no way to determine at runtime which flow should be executed within a "Run a child flow".

Seems like you need to add a lot of conditions like this:

... or find a different approach for your problem.

[Spearruleina]

I feel moderately disappointed to find this out, as i do not see the use in having what Power Automate calls a 'Custom value' which essentially remains hard-coded, literal and fixed, only more inscrutable (as a GUID) than a text name selected from a dropdown.

[Spearruleina]

I guess this setup at least saves you on the body of the input parameters.  You could at least dynamically define that one time, up front... (and then boom, giant switch statement! ; )

[Spearruleina]

Oops, not even that proves correct.  As soon as you enter specific workflow id, it still generates the specific schema for that workflow.  You can't get dynamic input parameters as just "body": <json> either...  
Why, then, the 'Enter custom value' at all?  No dynamic capacity, only an unreadable GUID instead of a text name...
A tease!  Maybe the next release? : )

[Chriddle]

You can create something like dynamic input parameters:

1. The child flow need one text input
2. The parent flow needs to create an object with the parameters that is passed to the child via string(obj)
3. The child uses json(objString) to convert it back into an object.

[Spearruleina]

True, i have used this technique sometimes to group related, nested sets of parameters to cut down on the count...

But this forces you to architect all the callees in a generic manner.  Which i guess you would do anyway if attempting to implement dynamic invocation? : )  It would still be nice if the collapse of the info could happen only on the dynamic caller, because without that, you may as well spell out the parameters on both ends anyway, for clarity, and since you can't actually dynamically call.