The "Column Filter Quickform" node presents a UI mask to select one or more data columns during a workflow execution. Practically, it is like a dynamic "Column Filter" node, where data columns can be selected on the fly at each workflow run.
In a workflow, for example, I was modelling fund returns based on 3 proxies returns, one fund of choice at a time. In the following data table I have the choice of modelling Fund 1, Fund 2, Fund 3, Fund 4, or Fund 5 based on Proxy 1, Proxy 2, and Proxy 3. In order to select a different fund each time, I need to use a "Column Filter" Quickform" node.
In addition, it also asks for an explanatory label about what we have to select here, some description of what the selection is for, a weight, and a variable name. The node in fact, when executed, creates a variable with the name given in the box "variable name" and the name(s) of the selected data column(s) as content. The "weight" setting ... well, let's keep the "weight" setting in mind for later.
1. a flow variable named "kept_columns" containing value "Fund 4"
2. an empty data table with the selected column
If I pack this sequence of nodes ("Column Filter Quickform" + "Reference Column Filter" + and maybe some additional nodes) into a meta-node, the meta-node acquires a "Configure" option in the context menu. The configuration window of the meta-node now shows the include/Exclude frame of the Quick Form to select the data column(s) plus its label and description.
Similarly to the meta-node, the KNIME server shows the "Column Filter Quickform" UI when executing the workflow. Indeed, the KNIME Server step-wise execution stops at each Quick Form node, showing the corresponding UI mask.
And this is the final content of the meta-node.