Variable Filter

This node filters local flow variables from all connections passing through it to prevent their availability in downstream nodes. A local flow variable is one that is defined in the same scoped context (e.g., local contexts such as KNIME loops) as this filter node. If the filter is used at the outermost level of the workflow, all variables can be filtered.

Caution: If a variable of the same name is passed in from another, enclosing scope and only overwritten locally, the filter only removes the local changes and restores the variable to its outside state. It is not possible to completely remove variables from any context other than the one they were defined in.

The following KNIME constructs create scoped contexts:

• Loops, including the loop start and loop end nodes,
• Try-Catch blocks,
• Workflow Capturing (Integrated Deployment), and
• Components, which have the special behavior of blocking all variables of outer contexts, with the option of copying some of them into the local context via the component input node, making them filterable.

An arbitrary number of port pairs can be added to the node. These ports are pass-through, but the corresponding output connections will have the filtering applied as described above.