Multiple File Upload - File Upload Widget and File Chooser Widget


KNIME AP 4.6.2
KNIME Server 4.15.1

I currently try to create a component for a workflow running on a knime server based on:

  1. First Problem: I use the combination of Refresh Button and File Upload widgets to load multiple files by writing each file to a temporary folder using the CSV writer. This actually works until I click the “Close and Apply temporarily” button. Which results in a duplication of my uploaded data. I still cannot find a mistake in the logic on how I connected the nodes. Is it possible that upon “Close and Apply temporarily” the Component is executed one more time? This would explain the duplication. If yes could one prevent this behaviour?

  2. I tried the “File Chooser Widget” on the local AP as well as on the server but it does not seem to work for me (I even downloaded a workflow from the hub) - see the picture below. Do I miss something using this widget or is there a bug in the current version?

  3. Is there an update on the current “Multiple File Upload” topic (I saw several forum entries on this matter) with a straight forward solution? This really is essential.

Many thanks in advance.

Hi @Anjo,

Thanks for contacting us!

  1. We would like to ask to provide us with an example of workflow.
    Also, components are reexecuted on Close and Apply, so this is a behavior that cannot be changed. You need to add some duplicate checks, probably.

  2. Do you use the widget inside a component on the server? We need an example of Workflow.

  3. Unfortunately, there are no updates yet.


Hi @dzhanhir,

many thanks for your reply and clarification.

  1. I was able to make it work by including a “Duplicate Row Filter” (very good hint) although it is kind of a workaround.

  2. The workflow runs on a server and I also tried the “File Chooser Widget” there but it "displayed the same message in the selection field as shown in my image. Here I just created an empty workflow with this particular Widget wrapped inside a component. So nothing special.

  3. Would be really great if this is taken up in one of the newer versions of KNIME (please vote 1 up if possible).

If I can find the time I will provide an example workflow but that might take a while. Nevertheless, the component I created based on the above mentioned component I just included some checks and wrote the tables to a temporary location inside the workflow.



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