While

Controlled node

Overview

The While node creates a conditional loop that repeatedly executes a workflow branch while a specified condition remains true. It reads a variable value on each iteration and compares it against a target value using a selected comparison operator. When the condition becomes false, the loop exits and execution continues.

This node is useful for polling operations, retry logic, counting loops, or any scenario where you need to repeat actions until a specific state is reached.

Inputs

Input	Type	Description	Default
run	Event	Triggers the node to evaluate the condition and either continue the loop or exit.	-
variableName	Text	The name or path of the variable to monitor (e.g., counter or {{status}}). Supports Handlebars templating to reference dynamic values.	-
[Dynamic]	Data	Additional inputs are dynamically created based on Handlebars variables referenced in the variableName field.	-

Outputs

Output	Type	Description
loop	Event	Fires when the comparison condition evaluates to true, signaling the loop body to execute again.
index	Number	The current iteration index (0-based) of the loop.
finished	Event	Fires when the comparison condition evaluates to false, indicating the loop has completed.

Runtime Behavior and Defaults

The While node evaluates the following properties on each iteration:

Property	Default	Description
operation	==	The comparison operator to use. Options: <, <=, ==, !=, >=, >.
breakValue	null	The target value to compare against the variable.

Execution Flow:

1. On the run event, the node reads the value specified by variableName from the variable store (checking local scope first, then global workflow scope).
2. It compares this value against breakValue using the selected operation.
3. If the comparison returns true, the node:
   • Outputs the current index (iteration count)
   • Fires the loop event
   • Schedules another iteration (repeat = true)
4. If the comparison returns false, the node:
   • Fires the finished event
   • Ends the loop (repeat = false)

Safety Limits: The node includes protection against infinite loops. If the iteration count exceeds the maximum loop limit (typically 10,000), the node throws a LoopCountExceeded error and stops execution.

Example Usage

Basic Counter Loop:

1. Create a SetVariable node to initialize a variable (e.g., counter = 0).
2. Connect it to the While node's run input.
3. Configure the While node properties:
   • variableName: counter
   • operation: <
   • breakValue: 5
4. Connect the loop output to your processing logic.
5. Connect the processing logic to another SetVariable node that increments counter by 1.
6. Connect that back to the While node's run input to form the loop.
7. Connect the finished output to the next step in your workflow.

In this setup, the loop executes 5 times (indices 0-4) and fires finished when counter equals 5.

Polling Pattern:

• Set variableName to {{apiResponse.status}}
• Set operation to !=
• Set breakValue to "completed"
• Connect the loop output to a delay node, then to your API request, then back to the While node.

The loop continues polling until the status equals "completed", at which point finished fires and the workflow proceeds.

Variable Scope

The While node checks for variables in the local scope first (variables set within the current sub-workflow), then falls back to the global workflow scope. This allows for encapsulated loop counters that don't pollute the global namespace.