getLocalStorage — GTM Variable Template for GTM

VARIABLES › GTM

getLocalStorage CORE GTM

Direct (.tpl) Apply (.tpl)

Retrieves a raw string value from localStorage and caches it during the current GTM event for performance optimization with string key.

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When to Use This

GTM Utilities

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

Browser Storage

Read from cookies, localStorage, and sessionStorage.

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Examples

Example 5

CONFIGURATION

Storage key: "user_preferences"

OUTPUT

"dark_mode=true"

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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.

Read-only Preview

getLocalStorage

Storage Key

💾 The key to look up in localStorage.

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.

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Related Variables

Same category: GTM

→ document.title → estimateReadingTime → gaEcommerceEventList → gaLeadGenerationEventList → getCookieValue → getDataLayerByEvent → getDataLayerCurrent → getDataLayerValue → getGaMeasurementIds → getRootDomain! → gtmIsDebugMode → gtmIsPreviewMode → hasLocalStorageKey → isGrantedAdPersonalization → isGrantedAdStorage → isGrantedAdUserData → isGrantedAnalyticsStorage → isGrantedFunctionalityStorage → isGrantedPersonalizationStorage → isGrantedSecurityStorage → 𝐀𝐑𝐑𝐀𝐘 From Indexed Values Generator - Array → 𝐀𝐑𝐑𝐀𝐘 From Values Generator - Array → 𝐂𝐎𝐌𝐌𝐀𝐍𝐃 𝐓𝐀𝐁𝐋𝐄 Lazy Generator (Advanced) - Object → 𝐎𝐁𝐉𝐄𝐂𝐓 From Arrays Generator - Object → 𝐎𝐁𝐉𝐄𝐂𝐓 Smart Generator - Object → 𝐎𝐁𝐉𝐄𝐂𝐓 Transformer Generator (Advanced) - Object

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Under the Hood

📜 View Implementation Code

/**
* Retrieves a raw string value from localStorage and caches it during the current GTM event.
* 
* @param {string} data.src - The key to look up in localStorage.
* @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 lookup.
* 
* @returns {string|null|undefined} The raw string value from localStorage, or null/undefined if not found.
*
* @framework ggLowCodeGTMKit
*/
const localStorage = require('localStorage');
const templateStorage = require('templateStorage');
const copyFromDataLayer = require('copyFromDataLayer');

const getLocalStorage = function(key) {
   const gtmId = copyFromDataLayer('gtm.uniqueEventId');
   if (gtmId === templateStorage.get(key + gtmId)) {
       return templateStorage.get(key);
   }
   const rawValue = localStorage.get(key);
   templateStorage.set(key, rawValue);
   templateStorage.set(key + gtmId, gtmId);
   return rawValue;
};
const safeFunction = fn => typeof fn === 'function' ? fn : x => x;
const out = safeFunction(data.out);
// ===============================================================================
// getLocalStorage - Direct mode
// ===============================================================================
const applyCast = (castFn, value) => safeFunction(castFn)(value);
const value = applyCast(data.pre, data.src);
return out(getLocalStorage(value));
// ===============================================================================
// getLocalStorage() – Apply Mode
// ===============================================================================
/*
return function(value) {
   return out(getLocalStorage(value));
};
*/


___WEB_PERMISSIONS___

[
  {
    "instance": {
      "key": {
        "publicId": "access_local_storage",
        "versionId": "1"
      },
      "param": []
    },
    "isRequired": true
  },
  {
    "instance": {
      "key": {
        "publicId": "read_data_layer",
        "versionId": "1"
      },
      "param": [
        {
          "key": "allowedKeys",
          "value": {
            "type": 1,
            "string": "specific"
          }
        }
      ]
    },
    "isRequired": true
  },
  {
    "instance": {
      "key": {
        "publicId": "access_template_storage",
        "versionId": "1"
      },
      "param": []
    },
    "isRequired": true
  }
]