pluckProperty — GTM Variable Template for Items

VARIABLES › ITEMS

pluckProperty EXTENDED Items

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

Extracts values from an array of objects by property name, filtering out null/undefined values.

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When to Use This

GA4 Ecommerce

Build and transform ecommerce data structures for GA4 event tracking.

Filtering

Select or exclude items from collections based on criteria or predicates.

Extraction

Pull specific values, segments, or patterns from complex data structures.

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Examples

Pluck property values▶ Try

INPUT

Items (Array of Objects with shared schema): [{name: "John", age: 30}, {name: "Jane", age: 25}, {name: "Bob", age: 35}]
Property Name: name

OUTPUT

["John", "Jane", "Bob"]

Empty array returns empty▶ Try

INPUT

Items (Array of Objects with shared schema): []
Property Name: name

OUTPUT

[]

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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.

pluckProperty

Read-Only Try Live

Items (Array of Objects with shared schema)

💾 Array of objects to extract values from.

Supported formats:
  ✓ Array

Property Name

💾 Property name to extract from each object.

Supported formats:
  ✓ String

Input Setup

Input Function (optional)

⚙️ Optional pre-processing function applied to the input 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.

Items (Array of Objects with shared schema) array

💡 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]

Property Name string

🔗 Result Handling — Chain Variables

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

pluckProperty()

+ Chain another variable

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Related Variables

Same category: Items

→ itemAssignDefaults → itemFilterByProperty → itemMapProperty → itemOmit → itemSet → itemSplitProperty → itemUniqByProperty → sumProductOfProperties → sumProperty → sumPropertyNested → ⚡ ITEMS › Transformer

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Under the Hood

📜 View Implementation Code

/**
 * Extracts values from an array of objects by property name, filtering out null/undefined values.
 *
 * @param {Array} data.src - Array of objects to extract values from.
 * @param {string} data.prp - Property name to extract from each object.
 * @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 processing.
 *
 * @returns {Array} Array of extracted values with null/undefined filtered out.
 *
 * @framework ggLowCodeGTMKit
 */
const pluckProperty = function(items, property) {
    const values = items.map(function(item) {
        return item && item[property] !== undefined ? item[property] : null;
    }).filter(value => value != null); // null == undefined returns true
    return values;
};
const safeFunction = fn => typeof fn === 'function' ? fn : x => x;
const out = safeFunction(data.out);
// ===============================================================================
// pluckProperty - Direct mode
// ===============================================================================
const applyCast = (castFn, value) => safeFunction(castFn)(value);
const value = applyCast(data.pre, data.src);
return out(pluckProperty(value, data.prp));
// ===============================================================================
// pluckProperty(...) – Apply Mode
// ===============================================================================
/*
return function(value, property) {
   property = data.rp1 ? property : data.prp;
   return out(pluckProperty(value, property));
};
*/

🧪 View Test Scenarios (5 tests)

✅ '[example] Pluck property values'
✅ Array with some objects missing the property - filters out undefined values
✅ Array with null values in property - filters out null values
✅ '[example] Empty array returns empty'
✅ Array with nested property access - extracts nested values