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getDataLayerCurrent — GTM Variable Template for GTM

VARIABLES › GTM
getDataLayerCurrent CORE GTM

Gets the current dataLayer object for a specific event or a property value from it.


When to Use This

GTM Utilities

Access GTM-specific APIs: dataLayer, debug mode, container settings.


Examples

Full object by event
INPUT
templateStorage: {
getItem: function(key) { return storage[key]; },
setItem: function(key, value) { storage[key] = value; }
}
Return Type:
fob
OUTPUT
page_view
Property value by event
INPUT
templateStorage: {
getItem: function(key) { return storage[key]; },
setItem: function(key, value) { storage[key] = value; }
}
Return Type:
dlv', key: 'page
OUTPUT
en

GTM Configuration

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Read-only Preview
getDataLayerCurrent
Return Type
Property Key
💾 Property to extract.

Supported formats:
  ✓ String (e.g. "page", "page_category, "ecommerce" )
Result Handling
Output Function (optional)
⚙️ Optional function to apply to the result before returning it.

Supported formats:
  ✓ Function

_____________
✏️  Examples

{{toCamelCase()}} - convert string to camelCase
{{undefinedTo("x")}} - convert undefined value to "x"
{{filter(GreaterThan(10))}} - keep values greater than 10


Under the Hood

📜 View Implementation Code
/**
 * Retrieves the current dataLayer event object or a specific property by gtm.uniqueEventId.
 * Searches up to 2 levels deep to handle wrapped structures.
 *
 * @param {string} [data.add] - Mode: "fob" for full object, "dlv" for dataLayer variable.
 * @param {string} [data.key] - Property name to extract (when add="dlv").
 * @param {Function|string} [data.out] - Optional output handler.
 *
 * @returns {Object|*} Full object (or {}) when fob, property value (or undefined) when dlv.
 *
 * @framework ggLowCodeGTMKit
 */
const copyFromDataLayer = require('copyFromDataLayer');
const copyFromWindow = require('copyFromWindow');
const templateStorage = require('templateStorage');

const CACHE_KEY = 'dlEvt';
const EVENT_ID_KEY = 'gtm.uniqueEventId';
const gtmId = copyFromDataLayer(EVENT_ID_KEY);

const getEventObject = function() {
    if (!gtmId) return undefined;
    
    const cache = templateStorage.getItem(CACHE_KEY);
    if (cache && cache.id === gtmId) {
        return cache.obj;
    }
    
    const dataLayer = copyFromWindow('dataLayer');
    if (!dataLayer) return undefined;
    
    const cacheAndReturn = function(obj) {
        templateStorage.setItem(CACHE_KEY, { id: gtmId, obj: obj });
        return obj;
    };
    
    const findEventObject = function(item) {
        if (!item || typeof item !== 'object') return undefined;
        
        if (item[EVENT_ID_KEY] === gtmId) {
            return item;
        }
        
        for (let key in item) {
            if (!item.hasOwnProperty(key)) continue;
            const nested = item[key];
            if (nested && typeof nested === 'object' && nested[EVENT_ID_KEY] === gtmId) {
                return nested;
            }
        }
        
        return undefined;
    };
    
    for (let i = dataLayer.length - 1; i >= 0; i--) {
        const item = dataLayer[i];
        if (!item) continue;
        
        const found = findEventObject(item);
        if (found) {
            return cacheAndReturn(found);
        }
        
        const itemId = item[EVENT_ID_KEY];
        if (itemId && itemId > gtmId) continue;
        if (itemId && itemId < gtmId) break;
    }
    
    return undefined;
};

const eventObject = getEventObject();
const safeFunction = fn => typeof fn === 'function' ? fn : x => x;
const out = safeFunction(data.out);
// ===============================================================================
// getDataLayerCurrent - Direct mode
// ===============================================================================
if (data.add === 'dlv') {
    return out(eventObject ? eventObject[data.key] : undefined);
} else {
  return out(eventObject || {});
}
// ===============================================================================
// getDataLayerCurrent() – Apply Mode
// ===============================================================================
/*
if (data.add === 'dlv') {
    return function(key) {
      return out(eventObject ? eventObject[key] : undefined);
    
🧪 View Test Scenarios (5 tests)
✅ '[example] Full object by event'
✅ Test Full Object mode with event not found returns empty object
✅ '[example] Property value by event'
✅ Test DataLayer Variable mode with event not found returns undefined
✅ Test DataLayer Variable mode with key not found returns undefined