Variable Interpolation

The syntax is simple: wrap the variable name in double curly braces: {{variableName}}

Basic Syntax

"Hello {{userName}}, you scored {{score}} points."

When this text is displayed:

{{userName}} is replaced with the value of the userName variable
{{score}} is replaced with the value of the score variable

Example:

If userName = "John" and score = 95
The text becomes: "Hello John, you scored 95 points."

Common Uses

Interpolation works in any text field in the Creator App. Here are the most common uses:

Show Text Action

Variable: userName = "Sarah"
Variable: completionTime = 120

Action: Show Text
Text: "Great job, {{userName}}! You completed the training in {{completionTime}} seconds."

Displays: "Great job, Sarah! You completed the training in 120 seconds."

Panel Titles and Descriptions

Variable: questionNumber = 3
Variable: totalQuestions = 10

Panel Title: "Question {{questionNumber}} of {{totalQuestions}}"
Panel Body: "You have {{attemptsRemaining}} attempts remaining. Choose wisely."

Displays:
Title: "Question 3 of 10"
Body: "You have 2 attempts remaining. Choose wisely."

Feedback Messages

Variable: score = 87
Variable: passingScore = 70

Text: "{{score}} out of {{passingScore}} is {{score >= passingScore ? 'Passing' : 'Failing'}}."

Displays: "87 out of 70 is Passing."

All Variable Types

Interpolation works with all variable types:

String Variables

Variable: selectedAnswer = "Option A"
Text: "You selected: {{selectedAnswer}}"
Displays: "You selected: Option A"

Number Variables

Variable: score = 92
Variable: attempts = 3
Text: "Score: {{score}}, Attempts: {{attempts}}"
Displays: "Score: 92, Attempts: 3"

Boolean Variables

Variable: isComplete = true
Text: "Complete: {{isComplete}}"
Displays: "Complete: true"

Note: Booleans display as “true” or “false”. For user-friendly text, use a ternary expression (see below).

Array Variables

Variable: completedSteps = ["Read Instructions", "Identify Valve", "Turn Valve"]
Text: "You've completed {{len(completedSteps)}} steps."
Displays: "You've completed 3 steps."

Arrays don’t interpolate directly (you can’t display the whole list). Use functions like len() to work with them.

Advanced: Using Expressions in Interpolation

In addition to simple variable names, you can use expressions inside {{ }}. This includes:

Ternary Expressions (If-Then-Else)

Variable: score = 85
Variable: passingScore = 80

Text: "You {{score >= passingScore ? 'passed' : 'failed'}} the quiz!"
Displays: "You passed the quiz!"

Formula: condition ? valueIfTrue : valueIfFalse Another example:

Variable: attempts = 2
Text: "{{attempts == 1 ? 'This is your first attempt.' : 'You have attempted ' + attempts + ' times.'}}"
// If attempts = 2, displays: "You have attempted 2 times."

Arithmetic

Variable: score = 92
Variable: maxScore = 100

Text: "You scored {{(score / maxScore) * 100}} percent."
Displays: "You scored 92 percent."

Function Calls

Variable: completedSteps = ["step1", "step2", "step3"]
Text: "Completed {{len(completedSteps)}} of 5 steps."
Displays: "Completed 3 of 5 steps."

Available functions:

len(value) — Length of string or array
clamp(v, min, max) — Constrain number between min and max
now() — Current timestamp (milliseconds)
In(stateId) — True when the given state is currently active

String Concatenation

Variable: firstName = "John"
Variable: lastName = "Smith"

Text: "Welcome {{firstName + ' ' + lastName}}"
Displays: "Welcome John Smith"

Undefined Variables: Default Behavior

What happens if you try to interpolate a variable that doesn’t exist or is uninitialized?

Variable: userName = undefined (or doesn't exist)
Text: "Hello {{userName}}, welcome!"
Displays: "Hello , welcome!"

The variable is replaced with an empty string. The text still displays, but with nothing in place of the variable. To avoid this:

Always initialize variables with a default value
Use a ternary expression to provide fallback text:

Text: "Hello {{userName === "" ? "Guest" : userName}}, welcome!"
// If userName is empty, displays: "Hello Guest, welcome!"

Real-World Examples

Quiz Feedback

Variable: score = 87
Variable: maxScore = 100
Variable: userName = "Sarah"
Variable: feedbackLevel = score >= 80 ? "great" : "okay"

Text: "{{userName}}, you did {{feedbackLevel}}! You scored {{score}} out of {{maxScore}} ({{(score / maxScore) * 100}} percent)."

Displays: "Sarah, you did great! You scored 87 out of 100 (87 percent)."

Personalized Status Message

Variable: currentStep = 3
Variable: totalSteps = 5
Variable: userName = "John"

Text: "{{userName}}, you're on step {{currentStep}} of {{totalSteps}}. {{totalSteps - currentStep}} steps remain."

Displays: "John, you're on step 3 of 5. 2 steps remain."

Time-Based Messaging

Variable: elapsedSeconds = 125

Text: "You've spent {{elapsedSeconds >= 60 ? 'over a minute' : 'under a minute'}}."

Displays: "You've spent over a minute."

Conditional Content

Variable: passScore = 80
Variable: actualScore = 92
Variable: feedbackURL = actualScore >= passScore ? "https://advanced.example.com" : "https://basic.example.com"

Text: "Click here for {{actualScore >= passScore ? 'advanced' : 'basic'}} content: {{feedbackURL}}"

Displays: "Click here for advanced content: https://advanced.example.com"

Where Interpolation Works

Interpolation is available in:

Location	Example
Show Text action text	`"You scored {{score}}."`
Show Panel title and body	`"Question {{currentQuestion}} of {{total}}"`
Narrative or audio cue text	`"Hello {{userName}}"`
Any text field in the Creator App	Anywhere you see a text input, you can interpolate

Where it doesn’t work:

Variable names and values (you can’t use interpolation in the Variable Inspector itself)
Condition expressions (use variables directly, not interpolated)

Testing Interpolation

When you preview your training:

Set variable values manually in the Variable Inspector preview to see how interpolation changes the text. For example:

Set userName = "Alice"
Preview the state
See text like “Hello Alice, welcome!”
Change userName = "Bob"
See text update to “Hello Bob, welcome!”

Best Practices

Keep interpolation readable

Avoid overly complex expressions in {{ }}. If it’s hard to read, it’s hard to maintain. Consider breaking complex logic into separate variables.

Always initialize variables

Set default values so interpolated text doesn’t show blanks. userName = "" is better than undefined.

Use ternary for conditional text

Instead of creating separate panels for different text, use {{condition ? text1 : text2}} to keep one panel that changes.

Be consistent with variable names

If you use userName in some places and learnerName elsewhere, you’ll confuse yourself. Pick a naming convention and stick with it.

Test with real data

Preview your training with actual variable values to make sure the interpolated text looks good and reads naturally.

Use friendly text

Even if score = 92, consider displaying “Great job!” instead of just the number. Use ternary expressions to show friendly feedback.

Common Mistakes

Forgetting quotes in expressions: If you use a string value in a ternary, add quotes: {{actualValue == 'correct' ? 'You got it!' : 'Try again'}}

Leaving uninitialized variables: If you interpolate a variable you forgot to create, it displays as blank. Always create and initialize variables first.

Using interpolation in conditions: Conditions use variables directly, not interpolation. Use score >= 80, not {{score}} >= 80.

Next Steps

Learn more about:

Creating Variables — Set up the variables you interpolate
Variable Types — Understand string, number, boolean, and array types
Conditions — Use variables to control training flow (not interpolation)

Creator App

Workflow

Transitions

Variables

Actions — Training Control

Actions — Step Instructions

Actions — Media Playback

Actions — Object Manipulation

Actions — UI Control

Actions — Speed & Time

Actions — Training Feedback

Actions — Hand & Tool Visualization

Basic Syntax

Common Uses

Show Text Action

Panel Titles and Descriptions

Feedback Messages

All Variable Types

String Variables

Number Variables

Boolean Variables

Array Variables

Advanced: Using Expressions in Interpolation

Ternary Expressions (If-Then-Else)

Arithmetic

Function Calls

String Concatenation

Undefined Variables: Default Behavior

Real-World Examples

Quiz Feedback

Personalized Status Message

Time-Based Messaging

Conditional Content

Where Interpolation Works

Testing Interpolation

Best Practices

Common Mistakes

Next Steps

​Basic Syntax

​Common Uses

​Show Text Action

​Panel Titles and Descriptions

​Feedback Messages

​All Variable Types

​String Variables

​Number Variables

​Boolean Variables

​Array Variables

​Advanced: Using Expressions in Interpolation

​Ternary Expressions (If-Then-Else)

​Arithmetic

​Function Calls

​String Concatenation

​Undefined Variables: Default Behavior

​Real-World Examples

​Quiz Feedback

​Personalized Status Message

​Time-Based Messaging

​Conditional Content

​Where Interpolation Works

​Testing Interpolation

​Best Practices

​Common Mistakes

​Next Steps

Basic Syntax

Common Uses

Show Text Action

Panel Titles and Descriptions

Feedback Messages

All Variable Types

String Variables

Number Variables

Boolean Variables

Array Variables

Advanced: Using Expressions in Interpolation

Ternary Expressions (If-Then-Else)

Arithmetic

Function Calls

String Concatenation

Undefined Variables: Default Behavior

Real-World Examples

Quiz Feedback

Personalized Status Message

Time-Based Messaging

Conditional Content

Where Interpolation Works

Testing Interpolation

Best Practices

Common Mistakes

Next Steps