Flag to not write a tab in the Excel Writer

I process Excels and produce dynamic the content of files within a loop. To avoid multple writes to the same Excel, I use the new feature with the additional tab input connectors. This works fine, but I realized, that I cannot disable writing one of those tabs. As a consequence I have to:

  • resort my tables (move all inactive ones to the end)
  • resort the tab name list accordingly
  • select in a dedicated writer node the correctly prepared Excel writer with the correct number of input tabs and write out the Excel

I found out, profiding this logic is no peace of a cake. Having the possibility to have only one node with your maximal number of input tabs but an option (at least accessible by flow variables) to enable/disable a tab to be written would be very helpful when processing Excels within a loop.

@marcogertsch you could try and use a case switch. Here is an example with the older node

Or you could explore and check out further examples or the KNIME Flow Control Guide.

Sorry, but may was to unspecified, but I implemented a logic based on a case. But this logic is not scalable and unflexible. Having this implemented as a switch in the node would extremly help to reduce complexity in my workflow. I must no longer resort the tabs dynamically and provide an excel writer for each possible number of (acitve) tabs. I invested days until this logic worked, the number of used nodes (and by this the save-time) just exploded (despite of using shared components). As I would love to deimplement this logic and replace it with node logic, more important is, that other Knimers may have similar needs and can avoid the big effort to implement add. logic.


@marcogertsch were you able use some of the examples? Otherwise you might want to provide us with an example illustrating your problem.

Hi, I mailed a big example of a workflow showing the slow Excel writer performance to Jürg Wasserman (see the other post KNIME 4.5.2 Excel Reader extremely Slow when reading from other sheet different than the first - #8 by JoergWas). Can you align with him? The Workflow shows how I dynamically handle the regrouping of potential empty tabs.
Is this ok for the moment or do you need more from my side?

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