pickNested — GTM Variable Template for Object

VARIABLES › OBJECT

pickNested EXTENDED Object

Direct (.tpl) Apply (.tpl)

Picks properties from a nested object using dot-notation paths.

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Examples

Pick nested properties▶ Try

INPUT

Source Object: {user: {name: "John", age: 30}, status: "active"}
keys: [{value: "user.name"}, {value: "status"}]

OUTPUT

John

Deep nested pick▶ Try

INPUT

Source Object: {user: {profile: {address: {city: "Paris", zip: "75001"}}, role: "admin"}}
keys: [{value: "user.profile.address.city"}, {value: "user.role"}]

OUTPUT

Paris

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GTM Configuration

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

pickNested

Read-Only Try Live

Source Object

💾 The source object to pick nested properties from.

Supported formats:
  ✓ Object variable: {{myObject}}
  ✓ Object literal: {user: {name: "John", age: 30}}

Property Paths to Pick

💾 Array of nested property paths to pick from the source object. Use dot notation for nested properties (e.g., "user.profile.name").

Supported formats:
  ✓ Nested path: "user.name", "settings.theme.color"
  ✓ Top-level: "status"

*** Pick nested properties***

*** Deep nested pick***

⊖

Add Row

Input Setup

Input Function (optional)

⚙️ Optional pre-processing function applied to the object before checking (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.keys(obj).length). 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]

Property Paths 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.

pickNested()

+ Chain another variable

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Related Variables

Same category: Object

→ applyFromObject → assignDefaults → assignDefaultsDeep → assignObjects → assignObjectsFromPairs → entries → getKeys → getValue → getValueByPath → has → hasKeyEqualTo → hasNested → mergeConcat → mergeConcatDeep → omit → parseJsonString → pick → set → toObjectPairs → values → zipObject

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Under the Hood

📜 View Implementation Code

/**
 * Creates a new object composed of selected nested properties using paths.
 *
 * @param {Object} data.src - The source object.
 * @param {Array} data.keys - Array of objects with path strings to pick (e.g., "user.profile.name").
 * @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 containing only the specified nested 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 pickNested = function(object, paths) {
    const result = {};
    if (object == null || typeof object !== 'object') return result;
    
    for (let i = 0; i < paths.length; i++) {
        const path = paths[i];
        const segments = path.split('.');
        let src = object;
        let valid = true;

        for (let j = 0; j < segments.length - 1; j++) {
            const key = segments[j];
            if (src == null || typeof src !== 'object' || !src.hasOwnProperty(key)) {
                valid = false;
                break;
            }
            src = src[key];
        }

        if (valid) {
            const lastKey = segments[segments.length - 1];
            if (src != null && typeof src === 'object' && src.hasOwnProperty(lastKey)) {
                // Only now write to result
                let dst = result;
                for (let j = 0; j < segments.length - 1; j++) {
                    const key = segments[j];
                    if (dst[key] === undefined || typeof dst[key] !== 'object') {
                        dst[key] = {};
                    }
                    dst = dst[key];
                }
                dst[lastKey] = src[lastKey];
            }
        }
    }
    
    return result;
};
const safeFunction = fn => typeof fn === 'function' ? fn : x => x;
const out = safeFunction(data.out);
// ===============================================================================
// pickNested - Direct mode
// ===============================================================================
const applyCast = (castFn, value) => safeFunction(castFn)(value);
const value = applyCast(data.pre, data.src);
const paths = createFlatArrayFromValues(data.keys, "value");
return out(pickNested(value, paths));
// ===============================================================================
// pickNested(...) – Apply Mode
// ===================================

🧪 View Test Scenarios (5 tests)

✅ '[example] Pick nested properties'
✅ '[example] Deep nested pick'
✅ Handle non-existent paths returns empty or partial object
✅ Pick multiple properties at same nesting level
✅ Invalid input returns empty object