For each

Splits a list property of the input record into single items and sends each item to Output, sequentially or in parallel. Use it to process the elements of a list one by one (call an API per item, map items, write them to a database).

Pins

Pin	Kind	Types	Description
Input	input	any (a flow type with a list or array property)	The record containing the list.
Output	output	generated <flow namespace>.ForEach<InputTypeName><InputProperty> or Viaducta.TypeSystem.Metadata.AnyData	One record per list item (see NoWrap).

Configuration

Field	Type	Default	Description
InputProperty	dropdown (property name)		Required. The list or array property of the input type to iterate. The options are the list/array properties of the input connection's type (flow types only). Selecting it regenerates the output type.
NoWrap	boolean	true	true: items are sent as they are. false: each item is wrapped in a generated record with one property Value.
ParallelRun	boolean	false	Process the items in parallel.
MaxParallelSlots	integer (1-512)	4	Maximum parallel items when ParallelRun is true; capped at the number of processor cores.
BatchMode	dropdown: 1 Auto, 2 Always, 3 Never	1	Whether the items of one list form a batch for batch consumers (Build array, Bulk insert, Write file, ...). Auto: only if the input record is not already in a batch; inside a batch (e.g. a file read by Read file) the items stay in that batch. Always: a child batch per list, e.g. to rebuild every list with Build array. Never: no batch.

Behaviour

• Reconfigure on InputProperty:
  • NoWrap = false: creates the flow type ForEach<InputTypeName><InputProperty> with a property Value of the item type and makes it the output type. Each item is emitted as a new record of this type with Value set to the item.
  • NoWrap = true: the output pin type is AnyData. Set the type of the outgoing connection to the item type (a flow type) and the items are emitted as that type; otherwise each item is wrapped in AnyData.
• For each input record the items of InputProperty are emitted in list order (sequential) or concurrently (parallel). The loop is synchronous: the For each finishes only after all items have been processed downstream (combine with Sync call to run something after the loop).
• Every item carries the metadata of the input record (the batch copy when a batch is opened); in parallel mode every item gets its own copy. For each does not provide the item index.
• When a batch is opened (BatchMode) it ends after the last item was processed downstream: consumers commit then; an error that reaches For each fails it and the consumers roll back.
• A null or empty list emits nothing. Without an outgoing connection nothing is processed.

Notes

• Changing NoWrap alone does not regenerate the output type; re-select InputProperty (or use its reconfigure button) after changing NoWrap.
• A Build array after a For each collects per batch: with BatchMode Auto and no incoming batch that is one array per list; inside an incoming batch use Always to get one array per list.
• In parallel mode expect the output order to differ from the list order.
• Inside an open Sql transaction the items are always processed sequentially (ParallelRun is ignored), because the transaction's connection can't be shared by parallel items.
• Only list/array properties of flow types are offered; lists of plugin types must be typed in by name.

Example

{ "InputProperty": "Orders", "NoWrap": true, "ParallelRun": false, "MaxParallelSlots": 4 }

Json deserializer → For each (connection type MyFlow.Order) → Http client → ...