mapTruthiness — GTM Variable Template for Value

VARIABLES › VALUE

mapTruthiness CORE Value

Direct (.tpl) Apply (.tpl) Add to GTM

Maps truthy values to one output and falsy values to another output.

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When to Use This

Conditional Logic

Branch logic based on conditions — if/else, ternary, boolean gates.

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Examples

Truthy maps to truthy value▶ Try

INPUT

Predicate Value: hello
Truthy Value: 1
Falsy Value: 0

OUTPUT

1

Falsy maps to falsy value▶ Try

INPUT

Predicate Value:
Truthy Value: success
Falsy Value: failure

OUTPUT

failure

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Live Sandbox

This is what you'll see when you open this variable in Google Tag Manager. Hover the icons for details.

mapTruthiness

Read-Only Try Live

Predicate Value

💾 The predicate value to evaluate for truthiness.

Supported formats:
  ✓ Any

Truthy Value

💾 The value to return when predicate is truthy.

Supported formats:
  ✓ Any

Falsy Value

💾 The value to return when predicate is falsy.

Supported formats:
  ✓ Any

Input Setup

Input Function (optional)

⚙️ Optional pre-processing function applied to the predicate before internal logic (e.g., convert object to string, normalize case). Internal transformations such as case handling will still apply afterward.

Result Handling

Output Function (optional)

⚙️ Optional function to apply to the result before returning it (e.g., str => str + ' €', val => val !== undefined for boolean conversion). Useful for chaining transformations on the output.

Predicate Value any

💡 Type any text to see the result update live

🎯 Using special value — click input to type instead

Test with:

Falsy undefined null "" empty 0 false NaN

Truthy true 42 "hello" {} empty [] empty {a:1} [1,2,3]

Truthy Value any

Falsy Value any

🔗 Result Handling — Chain Variables

Chain apply-mode variables to the output. Each variable receives the result of the previous one.

mapTruthiness()

+ Chain another variable

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Related Variables

Same category: Value

→ NaN → apply → applyChain → emptyArray → emptyObject → emptyObjectArray → emptyString → false → falseTo → falsyTo → filterValue → getLength → getType → identity → not → null → nullTo → parseValue → regexTableLookupAll → regexTableLookupCallback → true → undefinedTo → zero

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Under the Hood

📜 View Implementation Code

/**
* Maps truthy values to one output and falsy values to another output.
*
* @param {any} data.src - The input value to evaluate for truthiness.
* @param {any} data.tru - The value to return when the input is truthy.
* @param {any} data.fal - The value to return when the input is falsy.
* @param {Function|string} [data.out] - Optional output handler: function to transform result or string with format.
*
* Direct-mode specific parameters:
* @param {Function} [data.pre] - Optional pre-processor function to transform src before evaluation.
*
* @returns {any} The truthy value if input is truthy, otherwise the falsy value.
*
* @framework ggLowCodeGTMKit
*/
const mapTruthiness = function(predicate, truthyValue, falsyValue) {
   return predicate ? truthyValue : falsyValue;
};
const safeFunction = fn => typeof fn === 'function' ? fn : x => x;
const out = safeFunction(data.out);
// ===============================================================================
// mapTruthiness - Direct mode
// ===============================================================================
const applyCast = (castFn, value) => safeFunction(castFn)(value);
const predicate = applyCast(data.pre, data.src);
return out(mapTruthiness(predicate, data.tru, data.fal));
// ===============================================================================
// mapTruthiness(...) – Apply Mode
// ===============================================================================
/*
return function(value, truthyValue, falsyValue) {
   truthyValue = data.rp1 ? truthyValue : data.tru;
   falsyValue = data.rp2 ? falsyValue : data.fal;
   return out(mapTruthiness(value, truthyValue, falsyValue));
};
*/

🧪 View Test Scenarios (8 tests)

✅ Truthy value (true) - should return truthy value
✅ Falsy value (false) - should return falsy value
✅ '[example] Truthy maps to truthy value'
✅ '[example] Falsy maps to falsy value'
✅ Falsy value (0) - should return falsy value
✅ Truthy value (positive number) - should return truthy value
✅ Truthy value (empty object) - should return truthy value
✅ Truthy value (empty array) - should return truthy value