Helper flows

Helper flows allow for more efficient management and running of parent flows, such as an application event-driven or API Endpoint flow.

In the Workflows interface, a child flow is now referred to as a helper flow. The functionality for such flows remains unchanged.

Helper flows are useful in several scenarios:

  • You reuse a series of steps multiple times in a single flow or across multiple flows. By moving that series of steps into their own helper flow, you only need to create one flow that can be called multiple times. Run these steps from other flows by using the Call Flow or Call Flow Async functions.

  • You want to process a list one item at a time. For example, you can run a series of steps on each list item using the For Each function. Or, you can transform a list into a new list using the Map function.

  • You want to break a large flow into smaller, more manageable parts.

Use helper flows with list functions

Helper flows are helpful for list functions because they enable you to process individual items in a list.

Helper flows can have:

  • Inputs that correspond to the type of item in the list

  • Functions that perform a task on each item

  • A return (found in the Control category).

For example, you can convert an object into a list of objects, where each pair of keys and values gets converted to an object that has both propertyname and propertyvalue keys. This pattern is common among cloud APIs. where you prefix the propertyname string with the custom: text string. You can do that with a helper flow. It accepts a key, a value, and a constant prefix. The constant is the same across all iterations as the parent flow passes this constant to the helper flow. The helper flow returns back an object with two keys.

That flow, when used with object.map, can convert this simple object:

Copy 
{"this":"that","up":"down","left":"right"}

It returns the result in a more useful list:

Copy 
[
    {
        "propertyname":"custom:this",
                
        "propertyvalue":"that"
                
    },
                
    {
                
        "propertyname":"custom:up",
                
        "propertyvalue":"down"
                
    },
                
    {
                
        "propertyname":"custom:left",
                
        "propertyvalue":"right"
                
    }
]

Outputs from helper flows

Each helper flow card has the following outputs:

Field Definition
Inputs to this Flow Use the Click or drag to create option to add custom fields. Give each a name and data type (such as Text or Number). Each custom field that you create corresponds to an expected input from any flow that calls your helper flow.
context Outputs in this section are automatically assigned values whenever the flow runs.
Index This number output is assigned a value when a function that loops through the items of a list (such as the For Each or Map functions) calls the helper flow. The value of Index corresponds to the item's position in the list (starting with zero) as this instance of the flow processes the list.
Caller

The keys of the Caller object tell you:

  • Which flow called the helper flow (id and name)
  • Which particular execution of the flow made the call (execution_id)
  • Which particular step in the flow it was called (method, which is a unique ID).

When the helper flow is run manually, then id and execution_id are null. This fact is especially useful for debugging purposes.
Error Object output is assigned a value when the flow is called for error handling. See Set error handling for cards in flows.

The value of Error corresponds to the raw error object returns by the application or action that caused the error.

For example, an object often has keys that include message, statusCode and execution. The last key is the unique identifier of the flow execution that caused the error. You can then use it to construct a URL pointing to the execution history showing the flow details that led to the error.
Execution ID Unique ID of the flow instance.