Flow variables missing or not working

Hi eveyone,

Sometimes I feel a bit lost with the flow variables. It is really usefull when it works but when it does not, it is really frustrating. Here are two problems I met recently about these :

Problem 1 - File Reader module
In the “File Reader” module, I would like to store the file path in a variable called in this module :

It shoudl be possible but when I try to call the flow variable with “Use Variable”, the option is not available :

Does someone have an idea if there is a solution ?

Problem 2 - Flow variable not working on components
When I use the modules in the normal interface, there is no problem with the flow variables, everything is working perfectly :

I use them to set the graphs axis labels just fine :

But when I convert these “Line Plot” into a component, the flow variable are not recognized anymore so it doesn’t work :

Does someone have an idea why with the components it is not working anymore (but it works with metanode) ?

Thank you and have a nice weekend.

Hi @Gasperto

Always make sure the variable that you pass is of the correct type. You can check this within the Flow Variable tab. In this case, you need Path.


Since the table creator does not have a Path column type I’m fairly certain it’s currently a string. Use a String to Path node and you’ll see that the variable can be used :wink:

For components, you need to explicitly include the flow variables for them to become available (yes this is very annoying to work with). Go inside the component, double click on the Component Input and move all the variables to the Include section. The nodes will subsequently pick up the flow variables again.

Hope this helps!


Indeed annoying and also applies to the Component Output… you need to move it from red Exclude to Green Include in Component Output Configuration as well… really hope the Default may change at some stage…

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