Passing variables to components possible?


I have not found an answer to my question in the forum. I have a component, I actually would like to pass variables to.

Unfortunately, they do not end up therein (Register UUIDv4 Session with Processing Table VariableIn).

Is that possible at all or do I need to work around by conversion to table data and back (Register UUIDv4 Session with Processing Table TableIn)?

Kind regards


Hi @Thiemo.Kellner

Can you confirm that the component allows the flow variable to get in? Go inside the component, double click on the Component Input and check where the desired flow variable is.



Hi @ArjenEX

Thanks for caring.

Nope, there is none.

I am not sure whether this is an effect of the component being shared. Though, I think that I had it with an unshared component. Be it as it may, I just switched to the exclusion scheme, but it did not change anything.

That matters yes. I would try to unlink, execute the component and re-check the list.

Hi @Thiemo.Kellner , that is very odd. I haven’t been able to create a component in such a way that that variables are not present in the Component Input configuration! I see in the last screenshot you posted that the Component Input is showing a yellow triangle warning. Is that just because the upstream nodes have been reset? Even so, I still expect variables to show up.

If you are continuing to have problems with it, are you able to upload a basic workflow with your component in it, which exhibits the problem (i.e. just the Variable Creator, and the component, and replace the PostgreSQL connector with an H2 Connector to allow it to execute.)

Which version of KNIME AP are you using?

Hi @takbb

Thank you for taking it on. I’d be glad if it was the other way round. You encounter the oddities and my work goes smoothly. :upside_down_face: :wink:

However, quick reply

For the sample workflow, I need a bit of time. But I attached the originals for good measure.
load sources.knwf (61.0 KB)
Register UUIDv4 Session with Processing Table TableIn.knar (11.6 KB)
Register UUIDv4 Session with Processing Table VariableIn.knar (12.1 KB)

Well, I dare say, that I am not able to reproduce the behaviour.

Ok, it seems that there is some weird data corruption in the workflow. I imported the attached export and now it works as intended.

A compare between failing and working did not reveal anything.



Glad you got it working. The only thing I was going to suggest was that you disconnected the component, then open the Component Input, as for me it was also showing all the available variables, then make sure they are all moved to the "“include” side and then tick the “Enforce exclusion”, to ensure that all future variables are “included”.

(which now I am looking at it again, I think is what @ArjenEX was saying)

Then re-share the component.

Anyway, hope it stays working for you!

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I was. That has f’ed me up too many times :wink:

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Quite understandably. Will happen to me too, for sure.

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