While

While

Type: while  ·  Package: Core Activities v1.0.8

Repeats a block of activities as long as a condition is true. The condition is evaluated before each pass: if it is false from the start, the block never runs. Use it when you don’t know in advance how many passes you need — it depends on something that changes: “while there are more pages”, “while the queue has items”, “until the balance reaches zero”.

How it works

1. Evaluates the condition.
2. If it is true, runs the activities and goes back to step 1.
3. If it is false, it ends and the flow continues.

It supports Break (exit immediately) and Continue (skip to the next evaluation). Before each pass the loop checks whether the execution was terminated, so Terminate stops it between one pass and the next.

The condition is written the same way as in If: with the visual builder (column, operator and value, combined with AND/OR) or with a boolean C# expression. A visual builder with no rows counts as false, so the loop does not enter.

Required parameters

Parameter	Type	Default	Description
condition	bool	—	Condition evaluated before each pass. Visual builder or boolean expression. E.g. morePages.

Optional parameters

None.

Sub-flows

activities required

Activities that run on each pass while the condition is true.

Output

This activity does not return a value.

Example

Process a queue until it is empty:

Set Variable   name = hasItem   value = true

While   condition = hasItem
 └─ activities:
      Queue Get Item   queue = "invoices"   → output: item
      If   condition = isNull(item)
       ├─ then:
       │    Set Variable   name = hasItem   value = false   // nothing left: ends the loop
       └─ else:
            Invoke Playbook   path = "process.json"   input = { invoice: item }

Avoid the infinite loop

If the condition never becomes false, the loop runs forever and the execution hangs. Make sure something inside the body changes what the condition evaluates (a counter that goes up, a flag that turns off, a queue that empties). As a safety net, you can combine it with a maximum counter and a Break.

Common errors

Message	Cause and fix
'activities' is required.	The loop has no activities lane. Add at least one activity inside.
Value '…' is not numeric.	In the visual builder you used a numeric operator (greater than, less than…) with a field that is not a number. Convert the value with num(...) or use “equals”.
String '…' was not recognized as a valid Boolean.	The expression returned a text other than true/false. Write a comparison that yields true or false (status == "Pending").
The loop never runs	The condition was already false on entry, or the visual builder has no rows. Check the initial value of the condition’s variables.
The execution hangs	Infinite loop: the condition never changes. Make sure the body changes the condition and add a safety cap.

Related activities

• For Each — loop through the elements of a collection.
• For Loop — repeat a counted number of times.
• Break / Continue — control the loop from inside.