Feature Request: Enable definition of Expression-internal variables in Expression Nodes / Filter out helper columns

Feedback & Ideas
1

Hi all,

I’ve become a fan of the new Expression nodes and the KNIME Expression Language.

That said two features that I miss and I think could add a lot of value in terms of making complex Expressions more readible are:

  1. Ability to mark “helper-columns” for exclusion from the output table:
    1. e.g. I create interim columns that are solely required for a final calculation in a downstream column - the helper columns that enable the “final” Expression are not needed and I typically filter them out using Column Filter, Table Manipulator etc. A checkbox for each expression that allows to exclude it when a box is unchecked may be a nice quality of life improvement
  2. Ability to define a variable (not flow variable) inside an expression:
    1. E.g. in Column Expression (legacy), based on it’s Java Script backend, one could define a variable / multiple variables:
    2. var date = date(“2025-10-25”)
    3. And this could then be used downstream in expressions
    4. Would love to see this implemented again in Expression Language