Loop

Introduction

A loop is used to execute repeated actions and is visualized as a frame. For each iteration, the flow inside the loop is executed. The loop can be configured to iterate over a list or be based on a Boolean expression. For more information, see the Loop Type Property section below.

The loop can contain all types of elements used in microflows, except for start events and end events. Only a loop can contain break events and continue events.

Loop Variable

Within a loop, the $currentIndex variable contains the current number of loop iterations. This index starts at zero and increments with each iteration. For nested loops, $currentIndex holds the index of the innermost loop that the variable is part of. $currentIndex is also available when entering an expression for a While loop.

Loop Type Property

The two loop types are described below.

For Each (Item in the List)

This is the default type when creating a new loop activity, and it can be used to iterate over a list of objects. The list can be configured by setting the Iterate over property to a list in your flow scope, and for each object in the list, the flow inside the loop will be executed. The iterator (which looks the same as a parameter) represents the current object in the list for each iteration, and it can be renamed by setting Loop object name. This object is shown in black, and the entity type of the object is in blue.

For example, if you have a list of objects of the OrderLine entity and you want to set the purchase date for every object, you can use a loop with a change activity in it that sets the purchase date:

While (Condition Is True)

This loop type repeats the flow inside the loop many times until some condition evaluates to false. This condition is evaluated before each execution of the loop body. Typically, a While loop is used when it is impossible to determine the exact number of loop iterations in advance.

You can provide a description for the loop or the condition by setting the Caption field. The loop condition can be entered as an expression in the Expression editor, and it should result in a Boolean value. The While keyword is shown in blue, and the Caption is shown underneath in black.

For example, if you want to log numbers between 1 and 5, you can use a loop with a condition that checks whether a Counter variable is less than or equal to 5. Inside the loop, you would log the Counter value and add 1 to the Counter variable in order for the loop to stop executing when the Counter is greater than 5: