Using Handlebars Templating

Learn how to use Handlebars methods in MindStudio

Overview

MindStudio leverages the Handlebars templating language to make working with variables intuitive and powerful. Handlebars allows you to include, manipulate, and conditionally render data directly in your prompts, outputs, and logic.

Conditional Logic

Handlebars supports if-else logic for dynamic outputs, as well as other control expressions. For a full list of expressions, visit the Handlebars Documentation site.

{{#if userName}}
Hello, {{userName}}! How can we assist you today?
{{else}}
Hello! Please log in to get started.
{{/if}}

`{{#if condition}}`

Converts a conditional block that renders content only when the condition is true.

Example:

If isLoggedIn is true

Usage:

{{#if isLoggedIn}}
  Welcome back!
{{/if}}

Output:

Welcome back!

`{{#unless condition}}`

Converts a conditional block that renders content only when the condition is false.

Example:

If isLoggedIn is false

Usage:

{{#unless isLoggedIn}}
  Please sign in.
{{/unless}}

Output:

Please sign in.

`{{#each array}}`

Iterates over an array or object and renders the block for every item.

Example:

If items contains:

["Apple", "Banana", "Cherry"]

Usage:

{{#each items}}
  {{this}}
{{/each}}

Output:

opyApple
Banana
Cherry

`{{#with object}}`

Changes the evaluation context to the provided object for the enclosed block.

Example:

If user contains:

{ "name": "Alice", "age": 25 }

Usage:

{{#with user}}
  {{name}} is {{age}} years old.
{{/with}}

Output:

Alice is 25 years old.

Special Handlebars Methods in MindStudio

In addition to standard Handlebars features, MindStudio introduces special methods for advanced functionality:

`{{json varName}}`

Converts a JSON object into a string format.

Example:

If userProfile contains:

{
    "name": "John",
    "age": 30
}

Usage:

{{json userProfile}}

Output:

{"name":"John","age":30}

`{{sample varName number token}}`

Extracts a portion of the variable's content based on specified parameters.

Parameters:
- varName: The variable to sample.
- number: The number of items (e.g., lines, words, or letters). If negative, starts from the end.
- token: The type of unit to extract (line, word, or letter).
Examples:
- Extract the first 5 words:
  {{sample textVar 5 "word"}}
- Extract the last 3 lines:
  {{sample textVar -3 "line"}}
- Extract the first 10 letters:
  {{sample textVar 10 "letter"}}

`{{lookup object key}}`

Dynamically looks up a property from an object using a key.

Example:

If user contains:

{ "name": "Alice", "role": "admin" }

Usage:

{{lookup user "role"}}

Output:

admin

`{{get varName "property"}}`

Retrieves a nested property using a JSONPath expression from a JSON object.

Example:

If userDatacontains:

{
  "name": "Alice",
  "contact": { "email": "[email protected]" }
}

Usage:

{{get userData "$.contact.email"}}

Output:

[email protected]

`{{add num increment}}`

Adds a numeric increment to a given number.

Example:

If num is:

Usage:

{{add 5 3}}

Output:

`{{subtract num decrement}}`

Subtracts a numeric value from a given number.

Example:

If num is:

Usage:

{{subtract 10 4}}

Output:

`{{multiply value multiplier}}`

Multiplies two numbers.

Example:

If value is:

Usage:

{{multiply 2 5}}

Output:

`{{divide dividend divisor}}`

Divides one number by another.

Example:

If dividend is:

Usage:

{{divide 10 2}}

Output:

`{{eq var1 var2}}`

Checks if two values are equal using the double-equals operator.

Example:

If var1 contains:

and var2 contains:

"5"

Usage:

{{eq 5 "5"}}

Output:

true

`{{gt value1 value2}}`

Checks if the first value is greater than the second value.

Example:

If value1 is:

and value2 is:

Usage:

{{gt 10 5}}

Output:

true

`{{gte value1 value2}}`

Checks if the first value is greater than or equal to the second value.

Example:

If value1 is:

and value2 is:

Usage:

{{gte 10 10}}

Output:

true

`{{lt value1 value2}}`

Checks if the first value is less than the second value.

Example:

If value1 is:

and value2 is:

Usage:

{{lt 5 10}}

Output:

true

`{{lte value1 value2}}`

Checks if the first value is less than or equal to the second value.

Example:

If value1 is:

and value2 is:

Usage:

{{lte 5 5}}

Output:

true

`{{isEmpty varName}}`

Evaluates whether a variable is empty (null, undefined, an empty string, an empty array, or an empty object).

Example:

If data contains:

""

Usage:

{{isEmpty data}}

Output:

true

`{{length varName}}`

Returns the length of an array or a string. Returns "NaN" if the variable is not an array or string.

Example:

If list contains:

["a", "b", "c"]

Usage:

{{length list}}

Output:

`{{itemAt varName index}}`

Return an item from an array.

Example:

If list contains:

["a", "b", "c"]

Usage:

{{itemAt list 1}}

Output:

Note that the first item in an array is always index 0.

`{{firstItem varName}}`

Return the first item from an array.

Example:

If list contains:

["a", "b", "c"]

Usage:

{{firstItem list}}

Output:

`{{lastItem varName}}`

Return the last item from an array.

Example:

If list contains:

["a", "b", "c"]

Usage:

{{lastItem list}}

Output:

`{{markdown varName}}`

Converts a Markdown-formatted string into HTML.

Example:

If markdownText contains:

# Hello World
This is **bold** text.

Usage:

{{markdown markdownText}}

Output:

<h1>Hello World</h1>
<p>This is <strong>bold</strong> text.</p>

`{{formattedNumber number fractionDigits}}`

Formats a number using locale‑specific formatting with a fixed number of fractional digits.

Example:

If amount is:

1234.567

Usage:

{{formattedNumber 1234.567 2}}

Output:

1,234.57

`{{abbreviatedNumber number fractionDigits}}`

Formats a number into a compact, abbreviated notation (e.g., 1K, 1M) with a specified number of fractional digits.

Example:

If amount is:

Usage:

{{abbreviatedNumber 1500 1}}

Output:

1.5k

`{{date varName format}}`

Formats a date string according to the specified format. Supports both custom formats (e.g., "YYYY-MM-DD") and relative keywords like "fromNow" or "toNow". Any Moment.js-compatible date format can be used.

Example:

If dateString contains:

2020-01-01T00:00:00Z

Usage:

{{date dateString "YYYY-MM-DD"}}

Output:

2020-01-01

You can also format the current date by using currentDate as the variable:

Usage:

{{date currentDate "dddd, MMMM Do YYYY, h:mm:ss a"}}

Output:

Monday, June 9th 2025, 3:25:50 pm

Last updated 5 days ago