[Vernalis]: Error in Configurable IF/CASE Switch with Flow Variables losing its input or output link

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Hi @Vernalis,

The Configurable IF/CASE Switch (Flow Variable Value) Node in KNIME 5.2 appears to have a bug. I’m the creator of the workflow and when I updated my KNIME to the latest version and imported my workflow, all my Configurable IF/CASE Switch (Flow Variable Value) Nodes lost its input link or one of its output links.

I tried on different PCs, but the weird thing it’s that the issue happened in 2 out of 3 PCs. I looked for any bug report but it didn’t report the issue.

Cheers

1 Like
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Hi @bawh03,

A few questions first (but I have a suspicion what might be causing this):

  • Was this as a result of upgrading to KNIME 5.2.0 from an earlier version (or updating the Vernalis nodes)?
  • Is there anything in the console and/or KNIME Log about what has happened?

I’m also going to tag @steffen_KNIME here because I’m wondering whether this is possibly another consequence of the strange bug that manifested about port indexes in the node description (Steffen - I don’t remember if you were cc’d but it came to me from Benjamin Moser I think)

Steve

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Hi @bawh03 ,

sorry to hear you’re having issues here.

Some initial questions to help isolate the issue:

  • Are you using the modern UI? Are the connections also not present when opening the workflow in the classic UI?
  • Are the connections actually gone or possibly just not displayed (due to some UI bug)? Can you still execute the workflow as if the connections were present?
  • Does this issue also appear with newly created workflows or only with workflows created with a previous version?

If you can, it would also help if you shared your knime.log file after loading one of the affected workflows… You can find it via the UI (see screenshot), or at <workspace-dir>/.metadata/knime/knime.log.

image
image967×417 53.6 KB

Best,
Ben

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Hi, @BenjaminMoser and @Vernalis!

Thanks for the fast reply!

Here are the answers to the questions you both made:

  • Was this as a result of upgrading to KNIME 5.2.0 from an earlier version (or updating the Vernalis nodes)?

I believe as a result of updating KNIME to 5.2.0. I created the workflow on an earlier version.

  • Is there anything in the console and/or KNIME Log about what has happened?

Nothing, it’s like I saved the workflow like that and it isn’t shown as an error.

  • Are you using the modern UI? Are the connections also not present when opening the workflow in the classic UI?

I only use Classic UI and opened the workflow on this view. I’ve tried to open using Modern UI, but the error doesn’t show again. Actually, the error doesn’t show anymore to me, but I asked my colleague and it happened to them on Modern UI as well.

  • Are the connections actually gone or possibly just not displayed (due to some UI bug)? Can you still execute the workflow as if the connections were present?

The connections don’t exist, I can’t execute the workflow

  • Does this issue also appear with newly created workflows or only with workflows created with a previous version?

It happens on new workflows as well.

Cheers

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Thanks for the info, @bawh03

I tried reproducing your issue. Here’s what I did.

  1. Obtain 5.2.0 build from website
  2. Launch it, immediately switch to classic UI
  3. Install the “Vernalis nodes” extension
  4. Create a new workflow, add a Table Creator node, a Variable Creator node and connect them to a Configurable IF/CASE node.

I observed that I could not select a variable in the dropdown in the IF/CASE node configuration.

@Vernalis can you comment? See the attached log messages and workflow for details.

vernalis-configurable-ifcase.knwf (16.1 KB)
vernalis-ifcase.log (6.1 KB)

2 Likes
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The initial thought (based only on the log file) is that the node is not finding any flow variables to populate the dropdown with. Has anything changed in the KNIME APIs around listing available variables since KNIME 5.1? (I assume this works OK in KNIME 5.1?! Actually, it’s also a bit strange, because the node has test cases written in around KNIME 4.5 which still work on the community build server…)

I will also take a look at the example workflow, but that’s going to take a bit more time to sort out

Steve

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So, I have installed KNIME 5.2.0 vanilla from the website and installed the Vernalis community plugin.

  • The Configurable If/Case Switch (Flow Variable Value) node works as expected, and I am unable to see any loss of ports when importing older workflows, swapping back and forwards between classic and modern UI or anything else

  • @BenjaminMoser’s workflow does give an error, but that is because it uses the Configurable If/Case Switch node, which requires an integer flow variable to determine the port index.

Unfortunately this leaves us no further forwards, as I’m not able to reproduce the error nor see anything that looks in any way suspicious in the log files - can you provide a minimum workflow that reproduces the problem?

Steve

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Oh okay, I might have mixed up these two nodes then.

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