Do While Loop Event
The Do While Loop Event is similar to the While Loop Event, but with a key difference: the condition to exit the loop is checked at the end of each iteration. This ensures that the workflow inside the loop is executed at least once, even if the condition to exit the loop is initially false. The loop will continue until the condition evaluates to false after an iteration.
Overview
The Do While Loop Event allows you to run a series of actions in your workflow repeatedly, but the condition to stop the loop is evaluated only after the actions inside the loop have been executed. This makes it useful in scenarios where you need to ensure that the workflow inside the loop runs once, regardless of the condition, and then continue looping based on the condition evaluated at the end.
Configuring the Do While Loop Event
1. Title & Description
Just like the While Loop, begin by providing a Title and Description for the event to describe its purpose.
- Title: The name of your loop.
- Description: A brief explanation of what this loop will achieve.
2. Workflow Logic Before the Condition
In a Do While Loop, the logic to be executed in each iteration is placed before the condition. You can drag and drop various actions or operations that you want to run repeatedly before checking if the loop should continue.
Example: For instance, you could process a batch of orders or send notifications, which will run at least once before the condition is checked.
| Field | Description | Example Input |
|---|---|---|
| Actions | Add the workflow actions that need to be executed before checking the condition. | Update database, Send email, Process order |
Example:
- Action: Send notification email to user.
- Action: Update order status in database.
3. Binary Condition Setup (At the End of the Loop)
Once the actions inside the loop have been executed, the condition to break or continue the loop is evaluated at the end of the loop.
- Condition: Define the condition that will control whether the loop should continue or stop after one iteration.
- If the condition evaluates to true, the loop continues.
- If the condition evaluates to false, the loop breaks.
Example: The condition could check if a task is completed or if there are pending items in a queue. The loop will continue as long as the condition holds true, but it will exit once the condition evaluates to false after an iteration.
| Field | Description | Example Input |
|---|---|---|
| Condition | Define the condition that controls whether the loop should continue. | {queue_length > 0}, {is_order_pending} |
Example:
For this condition, the loop will continue running as long as there are pending orders in the queue (queue_length > 0).
4. Configuring the Workflow Inside the Loop
After setting up the binary condition, click on "Configure Whole Loop" to open the workflow builder canvas and define the logic inside the loop.
- Start Node: Represents the entry point of the loop.
- End Node: Marks the exit point of the loop.
5. Adding the Actions Before the Condition
In the workflow builder, you can begin by adding the actions to execute during each iteration of the loop. These actions will run before the condition to exit the loop is checked. You can add various operations based on your needs, such as sending emails, processing data, or updating records.
6. Binary Condition Node
At the end of the loop, a Binary Condition Node will evaluate the condition you set to determine if the loop should continue or exit.
- Configure the Condition: In this step, the condition will be checked after executing the logic in the loop. If the condition is false, the loop will stop. If it's true, the loop will continue.
Example:
If the condition is QueueLength > 0, the loop will continue as long as there are pending items in the queue.
7. Finalizing the Workflow
Once you’ve configured the logic and condition, you can save the workflow. The loop will continue to execute as long as the condition evaluates to true at the end of each iteration, ensuring at least one iteration of the workflow is completed.
Example Scenarios
Scenario 1: Processing Orders Until Complete
For a scenario where orders need to be processed in a loop, you can configure the loop to continue until all orders are completed:
- Actions: Process an order by updating the database and sending a confirmation email.
- Condition: After processing, check if there are still pending orders. The loop continues if there are pending orders.
Note: The loop will always run at least once, processing an order and checking if there are more orders to process.
Scenario 2: Sending Notifications to a Queue
If you're sending notifications to users in a queue, the loop will continue until the queue is empty:
- Actions: Send a notification to the next user in the queue.
- Condition: After sending the notification, check if there are more users in the queue. The loop stops once the queue is empty.
Example:
- Action: Send email to user.
- Action: Update notification status.
- Condition: Queue length must be greater than zero to continue.
Why Use the Do While Loop Event?
- Guaranteed Execution: The loop ensures that the workflow inside it is executed at least once before checking the condition.
- Dynamic Iteration: The loop continues to run as long as the condition at the end of the loop is true.
- Flexible Workflow: You can define any number of actions to run within the loop before evaluating the condition.
- Control Over Looping: The condition is checked at the end of the loop, providing flexibility in scenarios where initial actions must always occur before the condition is evaluated.
Final Thoughts
The Do While Loop Event is a powerful feature for automating tasks that need to run repeatedly but always require at least one iteration. It’s perfect for scenarios where you must perform certain actions first, and then check whether the condition is met at the end of the iteration. This flexibility makes it a great tool for dynamic workflows where actions must occur before a condition is evaluated to determine whether to continue or exit the loop.