Objective

This article explains how to use Liquid template expressions in Studio Flows to validate and branch on customer input, such as checking if a value is the correct length or matches a specific pattern. If you want to make decisions in your Studio Flow based on variables set by upstream widgets or Functions, Liquid templates provide a flexible way to access and evaluate those variables even when the Split widget UI does not allow direct reference to nested properties.

Product

Studio

Environment

Twilio Console

User Account Permission/Role(s) Required 

• Access to the Twilio Console
• Permission to edit Studio Flows

Procedure 

1. Set Up Your Studio Flow
   • Create or open your Studio Flow in the Twilio Console.
   • Add widgets to collect or process customer input (e.g., Gather, Run Function, Set Variables).
2. Understand Variable Scoping
   • Variables set by widgets are accessed as widgets.[widget_name].[property].
   • Variables set by Functions or Set Variables widgets may be available as flow.variables.[variable_name].
   • Some widgets (like Functions returning JSON) may nest values, e.g., widgets.myFunction.parsed.myProperty.
3. Using Liquid Templates in Split Widgets
   • When configuring a Split widget, you may find the UI only allows top-level variables (e.g., widgets.isValidInput), not nested ones (e.g., widgets.isValidInput.status).
   • To work around this, use a Set Variables widget before the Split to extract or transform the value you need using a Liquid template.
4. Example: Validating Input Length
   • Suppose you want to check if a customer’s input is exactly 6 digits.
   • Add a Set Variables widget before your Split.
   • In the Set Variables widget, create a new variable (e.g., digits_length) and set its value using a Liquid expression:

{{ widgets.gather_1.Digits | size }}

• This will set digits_length with the length of the Digits value and you will be able to compare it in the Split On widget with an expected value (e.g. 6 digits).

5. Branching on the Result
   • In your Split widget, reference the new variable (e.g., flow.variables.digits_length) to branch your flow based on whether the input is valid.
6. Accessing Nested Properties from Functions
   • If your Function returns a JSON object, access nested properties using the parsed key:

{{ widgets.stripalpha.parsed.validationStatus }}

• Use a Set Variables widget to extract this value if the Split widget does not allow direct reference.

7. Advanced: String Manipulation and Substrings
   • You can use Liquid filters to extract substrings or check patterns:
     • To get the first 3 characters:
       {{ widgets.gather_1.Digits | slice: 0, 3 }}
     • To check length:
       {{ widgets.gather_1.Digits | size }}

Additional Information 

• For more on Liquid templates in Studio, see Twilio Studio Liquid Template Language.
• For a practical example, see Creating Time-of-Day Routing in Twilio Studio Using Liquid Variables.
• If you encounter issues referencing variables in Split widgets, use a Set Variables widget to create a top-level variable for branching.

For further assistance, please reach out Twilio Support.