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Keeps only the items in a list where a predicate returns something truthy. The predicate is a small inner graph — open it by drilling into the node. It runs once per item and should evaluate to a boolean-ish value. An unconfigured or empty predicate keeps the list unchanged.

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Configuration

  • Source list assign — assigns key holding the list to filter.
  • Current item assign — the predicate reads the current item here. The iterated item is also used as the subject for Attribute nodes, so you can pick dated properties directly (e.g. first_name on an %Employee{}).
  • Output list assign — where the filtered list is written.

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Truthiness rules

The predicate result is unwrapped before the check:
  • nil, false, [], and "" are falsy.
  • A list of dated properties is truthy when any element is truthy — handy for “keep this employee if they ever matched X historically”.
  • Everything else (strings, numbers, structs) is truthy.

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On predicate error

If the predicate crashes or errors for an item, On inner error decides:
  • Skip branch (default): drop just that item and keep filtering the rest. This is the historical behavior — now the drop is logged at :error and the run is marked completed with issues instead of passing silently.
  • Halt flow: fail the whole run.

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Tips

  • Use Match or an arithmetic node as the final node of the predicate to return a boolean directly.
  • The Evaluator pane lets you paste sample JSON for the current item assign so you can preview the predicate without a real run.

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Ports