Advanced Mapping (Arrays, Iterators, Aggregators)

Created by Reachware Support, Modified on Thu, 2 Apr at 2:05 PM by Reachware Support

For advanced array processing beyond simple mapping, use Iterator and Aggregator logic processors to apply complex transformations to each item, filter items based on dynamic conditions, perform calculations on each item separately, and combine results after processing.

loopOverItems

Quick mapping for simple arrays

Iterator & Aggregator

Advanced processing for complex scenarios

Iterator & Aggregator Flow

Source — provides the array

↓

Iterator — one item per loop

↓

Process — your custom logic

↓

Aggregator — merges back

↓

Destination — final output

How Iterator Works

Iterator splits an array into individual objects, allowing each item to be processed separately through the flow.

What happens:

Iterator receives the array from the source

Splits the array into separate objects

Each object flows through subsequent operations

Each item is processed independently

How Aggregator Works

Aggregator combines individual objects back into a single array after each item has been processed.

What happens:

Receives processed objects from Iterator

Combines them into a single array

Outputs the complete array to the next operation

Nested Arrays Example

Source data contains arrays inside arrays with line items need to use a two-level Iterator strategy.

Input:

[
  {
    order: "ORD-001", customer: "Alice",
    items: [
      { sku: "A", price: 100, qty: 2 },
      { sku: "B", price: 50, qty: 1 }
    ]
  },
  {
    order: "ORD-002", customer: "Bob",
    items: [
      { sku: "C", price: 200, qty: 3 }
    ]
  }
]

Two-level Iterator strategy

Outer Iterator

Loops over orders

Loop 1 → ORD-001 (Alice)
Loop 2 → ORD-002 (Bob)

Inner Iterator

Loops over each order's items[]

ORD-001 → sku:A (qty:2, $200)
ORD-001 → sku:B (qty:1, $50)
ORD-002 → sku:C (qty:3, $600)

Inner Aggregator → Outer Aggregator

Inner collects line totals per order. Outer recombines all orders into the final array.

Output:

[
  { order: "ORD-001", customer: "Alice", orderTotal: 250 },
  { order: "ORD-002", customer: "Bob", orderTotal: 600 }
]

When to Use What

Situation	Use	Why
Extract a single field from all items	loopOverItems	Simple mapping, no per-item logic needed
Calculate a value per item (price × qty)	Iterator & Aggregator	Each item needs its own computation step
Filter items by a condition	Iterator & Aggregator	Use a Router or Filter node between them
Call an API once per item	Iterator & Aggregator	Each item triggers an independent HTTP call
Process nested arrays	Iterator & Aggregator	Nest a second Iterator inside the first