Build array

Collects single records arriving on Input into one collection record and sends it to Output when the batch they belong to completes (e.g. one file read, one Sql query execution), or, for records without a batch, when the buffer is full or after an idle timeout. Use it to batch records for bulk inserts, bulk API calls or to rebuild a list after a ForEach.

Pins

Pin	Kind	Types	Description
Input	input	any	Single records to collect. Connect it before reconfiguring, the input type determines the generated output type.
Output	output	generated <flow namespace>.<InputTypeName>Collection	A record with one list property Items holding the collected input records.

Configuration

Field	Type	Default	Description
OutputProperty	string	Items	Required. Name of the list property on the output type. Changing it regenerates the output type (see Notes: keep Items).
BatchSize	integer	0	Maximum records per output record. 0 = unlimited: in a batch the whole batch, without a batch until the timeout.
AutoFlushTimeout	integer (ms, 50-10000)	500	Records without a batch only: idle time after the last added record after which the collected records are flushed.
BatchScope	batch scope selector	empty	Which batch is collected into one array. Empty = the closest batch producer upstream. A component id of a batch producer upstream = the batches of that producer. None = ignore batches.

Behaviour

• Reconfigure (changing OutputProperty or pressing its reconfigure button) creates the flow type <InputTypeName>Collection in the flow's namespace with a list property Items whose item type is the input type, and sets it as the type of Output. Without this step the component has no output type and silently drops every record.
• Records in a batch (see BatchScope) are collected per batch. When the whole batch has been processed the array is sent with the metadata of the last record; it stays in the batch, so batch consumers behind Build array (Write file, Bulk insert) include it before they commit. When the batch failed the records are discarded. With BatchSize > 0 a full array is sent right away and the rest at the end. No timeout, no record positions involved, concurrent batches never mix. If the selected producer is not upstream of a record, the record fails.
• Records without a batch (or BatchScope None) are added to an internal buffer. A flush (one record on Output, buffer cleared) happens when:
  • BatchSize > 0 and the buffer holds BatchSize records;
  • no record was added for longer than AutoFlushTimeout ms. The idle check starts with the first record and runs every AutoFlushTimeout ms, so the actual delay is between one and two timeouts.
• The output record carries the metadata of the record that triggered the flush (for the timeout flush: of the last received record).
• Stream boundaries come from batches; records without a batch have none.

Notes

• The generated type always names the list property Items, whatever OutputProperty says, and on start the plugin checks that the output type has a property named OutputProperty. Any other value makes the flow fail to start ("There is no ... defined on the output type"). Keep OutputProperty = Items.
• Without a batch the array is closed only by BatchSize or the timeout: records of several sources that arrive within one timeout end up in the same array. Put a batch producer upstream for exact boundaries.
• Without a batch the buffer is shared by all callers of the component: records from concurrent requests end up in the same array.
• The generated item type is declared in the flow's namespace with the input type's short name; it works best when the input type is a flow type.

Example

{ "OutputProperty": "Items", "BatchSize": 100, "AutoFlushTimeout": 1000 }

Database reader → Data mapper → Build array → Http client (bulk POST)