Hi Lars,
Thanks for trying to develop native Python nodes for KNIME!
Unfortunately, what you are trying to do is currently not possible. The only part where we claim interactivity of the Python nodes is that a view written in Python is not a static image anymore as in the legacy Python integration and can synchronize the selection of data points with other views in KNIME (those need not be Python-based).
This is due to the execution model of KNIME nodes in general: as soon as the execution has finished, its output must be fully available and – in the case of Python nodes – we need to be able to dispose of/reuse the Python process.
For Python view nodes this means that once the node is executed, it needs to provide an image or HTML page that represents the view. This HTML page must be self contained and currently cannot communicate in any other way with KNIME than by sharing the selection (which, e.g. in a DataApp, means that this selection resides purely within the HTML page that composes all views).
Getting back to your use case, couldn’t you use a Table View – KNIME Community Hub node for this?
Hope that helps,
Carsten