The iterator construct in Flogo enables the iteration of a single activity. The configuration elements are associated with that activity. In Flogo, you can iterate only over a single activity. The iterator acts much like a foreach loop in any procedural language. If you need to iterate over multiple activity calls, simply place an iterator on a subflow.

Flow configuration

Iterators are associated with an activity. The activity must have the type declared and set to iterator, as well as the iterate setting defined and the value would be either the array to iterate over or a scalar value.

  "id": "log_2",
  "type": "iterator",
  "name": "Log",
  "description": "Logs a message",
  "settings": {
    "iterate": 1
  "activity": {
  "ref": "#log",
  "input": {
    "addDetails": false,
    "message": "=string.concat(\"Hello \", $"

A few important things to note:

  • A new settings element with a property named iterate set to the array that should be iterated over. It is also possible to define a static value, for example, if the value of “10” was specified, the iterator construct would invoke this activity 10 times
  • The $iterate scope has now been introduced and can be used to access the value and key of the current iteration.

The $iterate scope has two properties:

  • $current[value]: The value of the current iteration, that is, the object of the current array
  • $current[key]: The current key (1, 2, etc)