Call Workflow: Path Column throws error

[mwiegand]

Hi,

apologize to be a bit to verbal but the Path type, introduced years ago, is just causing too much frustration.

Neither can a path variable be passed to a receiving worklfow nor as a table column. In fact, the presence of path type as a column breaks the Call Workflow node:

ERROR Container Input (Variable) 11:1224    Caught "NullPointerException": Cannot invoke "org.knime.core.data.IDataRepository.addFileStoreHandler(org.knime.core.data.filestore.internal.IWriteFileStoreHandler)" because "dataRepository" is null
ERROR Call Workflow (Table Based) 10:1699    Execute failed: Failure, workflow was not executed, current state is IDLE.
ROOT : IDLE (start)
ROOT (end)

If I read the below posts correctly, this has been flaged years ago!

Call Workflow (Table) and Container Input (Variable) broken

Hej, I just wanted to call an extern workflow by “Call Workflow (Table)”, which should pass a table, variables and credentials. But when I use the current implementation of “Container Input (Variable)” in the to-be-called workflow, it cannot be selected to receive the variables, but only as target to push the credentials to it. The other two nodes (Container Input Table and Container Input Credentials) work fine, though (except for that he Path of an SMB Connector is not passed through in the T…

Call the workflow table based on the variable that does not accept with the path

Hi, I have a main workflow that I use several times with different input files. I would need to call a second workflow via variable workflow, I tried the Call Workflow (Table Based) but I can’t pass the path of the second workflow.The path written directly in the node works correctly, can anyone help me? [CallWkf] If it’s not possible with table based is it possible in some other way? The important thing is that you can call via variable If it helps, the main wkf and the one called are in tw…

It was presumably fixed in 4.4.2 so either it’s a regression, was never fixed or I misinterpreted the post.

Here is the test workflow.

mwiegand/Public – 77150 - Call Workflow not passing Path Variables and errors...

Merry X-Mas my fellow Knimers!

Cheers
Mike

[k10shetty1]

@mwiegand Thank you for reporting this, as mentioned in this thread

Call the workflow table based on the variable that does not accept with the path

Hi, Have you tried the Call Workflow Service together with Workflow Service Input and the corresponding Workflow Service Output nodes? Call Workflow Service definitely works with flow variables, I have done it before. It is also the better option if you do not want to invoke the callee workflow from outside of KNIME, as it uses a more efficient proprietary format for data representation (Call Workflow (Table Based) uses JSON). Kind regards, Alexander

I can confirm that Path columns work fine when using Call Workflow Service together with Workflow Service Input / Output. I tested this setup, and it runs without errors. So, as a workaround, you can try switching from Call Workflow (Table Based) to the service-based nodes.