pick — GTM Variable Template for Object

VARIABLES › OBJECT

pick EXTENDED Object

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

Returns a new object with only the specified keys.

---

When to Use This

---

Examples

Pick single property▶ Try

INPUT

Source Object: {name: 'John', age: 30, city: 'Paris', country: 'France'}
Properties to Pick: [{value: 'name'}]

OUTPUT

John

Pick multiple properties▶ Try

INPUT

Source Object: {id: 1, name: 'Product', price: 99, stock: 50, category: 'electronics'}
Properties to Pick: [{value: 'name'}, {value: 'price'}, {value: 'category'}]

OUTPUT

Product

---

Live Sandbox

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

pick

Read-Only Try Live

Source Object

💾 The source object to pick properties from.

Supported formats:
  ✓ Object variable: {{myObject}}
  ✓ Object literal

Properties to Pick

💾 List of property names to pick from the source object. Only properties that exist in the source will be included.

Supported formats:
  ✓ String: property name
  ✓ Array of strings: for multiple properties at once

*** Pick single property***

*** Pick multiple properties***

⊖

Add Row

Input Setup

Input Function (optional)

⚙️ Optional pre-processing function applied to the source object before picking properties (e.g., normalize object structure, parse JSON).

Result Handling

Output Function (optional)

⚙️ Optional function to apply to the result object before returning it (e.g., obj => JSON.stringify(obj), obj => Object.freeze(obj)). Useful for chaining transformations on the output.

Source Object object

💡 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]

Properties to Pick list

✕

+ Add Row

🔗 Result Handling — Chain Variables

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

pick()

+ Chain another variable

---

Related Variables

Same category: Object

→ applyFromObject → assignDefaults → assignDefaultsDeep → assignObjects → assignObjectsFromPairs → entries → getKeys → getValue → getValueByPath → has → hasKeyEqualTo → hasNested → mergeConcat → mergeConcatDeep → omit → pickNested → set → toObjectPairs → values → zipObject → ⚡ OBJECT › From Arrays → ⚡ OBJECT › Smart → ⚡ OBJECT › Transformer (Advanced)

---

Under the Hood

📜 View Implementation Code

/**
 * Creates a new object composed of selected properties from the source object.
 *
 * @param {Object} data.src - The source object.
 * @param {Array} data.kys - Array of objects with property names to pick.
 * @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 {Object} A new object with only the selected properties.
 *
 * @framework ggLowCodeGTMKit
 */
const getType = require('getType');
const createFlatArrayFromValues = function(list, property) {
    const result = [];
    if (!list) return result;
    for (let i = 0; i < list.length; i++) {
        const val = list[i][property];
        if (getType(val) === 'array') {
            for (let j = 0; j < val.length; j++) {
                result.push(val[j]);
            }
        } else if (val) {
            result.push(val);
        }
    }
    return result;
};
const pick = function(object, keys) {
    const result = {};

    if (object == null || typeof object !== 'object') {
        return result;
    }

    for (let i = 0; i < keys.length; i++) {
        const key = keys[i];
        if (object.hasOwnProperty(key)) {
            result[key] = object[key];
        }
    }

    return result;
};
const safeFunction = fn => typeof fn === 'function' ? fn : x => x;
const out = safeFunction(data.out);
// ===============================================================================
// pick - Direct mode
// ===============================================================================
const applyCast = (castFn, value) => safeFunction(castFn)(value);
const value = applyCast(data.pre, data.src);
const keys = createFlatArrayFromValues(data.kys, "value");
return out(pick(value, keys));
// ===============================================================================
// pick(...) – Apply Mode
// ===============================================================================
/*
return function(object, keys) {
   keys = data.rp1 ? createFlatArrayFromValues(data.kys, "value") : keys;
   return out(pick(object, keys));
};
*/

🧪 View Test Scenarios (5 tests)

✅ '[example] Pick single property'
✅ '[example] Pick multiple properties'
✅ Test picking non-existent properties
✅ Test with array of keys in value property
✅ Test with empty keys array