Read XLS Sheet Names node causes error in web portal

Hi. I'm trying to develop a simple workflow (attached) that lets the end user upload an Excel file to the KNIME server then dynamically select the sheet to use. However when I publish to our web portal the Read XLS Sheet Names node produces the following error:

Execute failed: /tmp/poifiles/poi-ooxml--946060281.tmp (No such file or directory)

Our KNIME server (version 4.1.1) is running Linux.

Thanks in advance for any help


Interesting use case, I am happy to help. There are a couple of issues: To have all QuickForm (QF) nodes to be shown on the KNIME WebPortal, those need to be encapseled into so called Wrapped Nodes, please make sure you have injected and extracted the respective variables via the WrappedNode Input and Output nodes within the Wrapped Node. The only real problem I am seeing is that the QF node within the Upload XL node is not configured properly and need to have the option "Disable output, if file does not exist" enabled, which is because the file which has been used during configure time on the client does not exist when running through the wizard execution. Hope this helps?

Hi Gabriel,

Thanks for the tips. After following your suggestions, the workflow worked for several executions on the server. Unfortunately, it then reverted to the error I mentioned before. Perhaps you can reproduce the problem? After doing a little googling, I suspect this might be a bug in the Apache POI API (though I'm not positive). The temp directory may be getting deleted. May be related to this POI bug which was recently fixed