For Loops In Flows
When most flows begin, they pass the trigger's payload to the data chain and execute once. This recipe explains how to execute a flow for each element in a payload's array.
Author: Eron Powell
Directus Version: 9.18.1
Sometimes you may have an array of data you'd like to iterate over and run operations on, one-by-one. However, you may have noticed that each operation in a flow executes just one time. Because of this, you can't create a "for-loop" within the operations of a single flow.
However, to achieve a "for-loop", you can instead use the trigger flow operation to pass the data into an another flow trigger. When this type of trigger receives an array as a Payload, the flow runs for each item in the array individually.
Remember: for some use-cases, you can also iterate through data in a Run Script operation.
You'll need a flow with an array of data on its data chain.
Configure the Starting Flow
- Configure a flow a trigger flow operation.
- Under Payload, be sure to add the desired array.
- Save and exit the flow.
Configure the "For-Loop" Flow
Once your starting flow is configured as desired, follow these steps.
- Create a flow using the another flow trigger.
- Configure operations as desired.
Once your for-loop is configured, you can process the data several ways.
First, you could simple let the "for-loop" flow process each element in the Payload.
Second, you could also configure a Response Body in the trigger of your "for-loop" flow. The Response Body gets appended under the trigger flow operation in the starting flow.
Third, you could add another trigger flow operation into the "for-loop" flow, to create complex flow chains. If you do this, just keep API performance in mind. If you configure a Response Body, the parent flow will halt execution until it receives Response Body.
Good luck and have fun! 🧑🍳