Guide - Return values

This follows on from the general concepts in the logs, errors, and outputs guide.

This guide explains how Streamscript actions return both primitive values and record/collection types without the need for Apex code. Streamscript marshals all values into pre-defined output variables based on the data type.

Pull from automatic output values...

...or push into manually assigned variables

Expression Return

Any expression may appear after the return keyword. Streamscript automatically sets the action's output variable (num, bool, text, list, record, records) according to the data type.

# Streamscript (inverse exchange rate)
$result = Json-Decode $http.body
return 1 / $result.rates.USD

Variable Return

Any script variable may be returned as a flow resource, including records and collections.
When returning records and lists, the variable name must indicate its type, eg: return $Account
Flow API names are case sensitive: $name__c $Name__c $Name__C are all different names.

return $num

return $bool

return $text

return $texts

return $Account # map

return $Contact # list of maps

Dates, times, datetimes or blobs are returned by assigning to a field of that type on a record. Returning a map is achieved by returning a record with its fields populated, which behaves map-like on the flow canvas.

This example retrieves a PDF invoice. The binary blob is stored on the Document Body field, then it returns the $Document record so that Flow can insert it. The HTTP body is base64 to match the Document body field.

# get pdf binary blob, represented as base64
$url = 'https://www.tryitapi.com/invoice.pdf'
$pdf = Http-Get $url -base64

# new record
$Document = New-Document {
    Name = 'inv.pdf'
    Body = $pdf.body
}

# output as SObject
return $Document

Parameterised Return

Instead of one variable, you may simultaneously return any/all of the above variables. This example returns an Opportunity header and a list of OpportunityLineItem simultaneously:

# shopping cart
$Opportunity = New-Opportunity
$Opportunity.Name = $cart.shopping_cart_name

# each item in cart
$OpportunityLineItem = []
foreach ($item in $cart.shopping_cart_items) {...}
return -record $Opportunity -records $OpportunityLineItem

Another example - issue a POST request and return the HTTP response attributes to flow:

# Streamscript
$Http = Http-Post 'callout:httpbin/post'
$body = $Http.body
$status = $Http.status
$headers = $Http.headers.values()
return -num $status -text $body -texts $headers

Parameterized return values must be either literals or $variables. If you wish to return a long reference such as $map.value.text, assign the final value to a distinct $text variable, prior.

Null Return

Returning a value from a script is optional. Scripts that return nothing are said to return null. There is no value, but the script ends and flow proceeds to the next element.

# Streamscript
if ($record_already_exists) return
...

Implied Return

One-line scripts automatically return the result of the expression. Streamscript will set the output variable (num, bool, text, list, record, records) according to any result data type.

# Streamscript (returns boolean)
BusinessHours-IsWithin 'Eastern Standard Time' {!$Flow.InterviewStartTime}

That sums up the ways to pass data from Streamscript back into Flow.