[null,null,["อัปเดตล่าสุด 2025-07-25 UTC"],[[["\u003cp\u003eSandboxed JavaScript in Google Tag Manager offers a secure environment to execute custom code with limited features for safety.\u003c/p\u003e\n"],["\u003cp\u003eIt utilizes a simplified type system and lacks access to the standard JavaScript global execution environment, relying on a \u003ccode\u003erequire\u003c/code\u003e function for functionalities like \u003ccode\u003eencodeURI\u003c/code\u003e or \u003ccode\u003esetTimeout\u003c/code\u003e.\u003c/p\u003e\n"],["\u003cp\u003eCustom template code acts as a function executed upon tag firing or variable evaluation, receiving configured data through a \u003ccode\u003edata\u003c/code\u003e parameter.\u003c/p\u003e\n"],["\u003cp\u003eThe provided sample demonstrates building a beacon tag using \u003ccode\u003erequire\u003c/code\u003e for functionalities and accessing configuration data via \u003ccode\u003edata\u003c/code\u003e.\u003c/p\u003e\n"]]],["Sandboxed JavaScript, used in Google Tag Manager's custom templates, provides a safe execution environment with restricted features. It uses a simplified type system and lacks the standard `window` object, instead relying on a `require` function for globals. It supports basic types and literal array/object creation. Template code represents a function body with a `data` parameter containing UI-configured values. Code example uses functions `sendPixel`, `encodeUri`, `encodeUriComponent` for building a URL and appending cache buster parameter, then send the pixel with `sendPixel`.\n"],null,["# Sandboxed JavaScript is a simplified subset of the JavaScript language that\nprovides a safe way to execute arbitrary JavaScript logic from Google Tag\nManager's custom templates. To provide a safe execution environment, some\nfeatures of JavaScript are restricted or removed. Sandboxed JavaScript is based\non ECMAScript 5.1. Some ECMAScript 6 features such as arrow functions and\n`const`/`let` declarations are available.\n\nGlobal execution environment\n----------------------------\n\nSandboxed JavaScript is not executed in the standard global execution\nenvironment like normal JavaScript, so the `window` object and its properties\nare not available. This includes methods defined in the global scope like\n`encodeURI` or `setTimeout`, global values like `location` or `document`, and\nglobal values defined by loaded scripts. In place of these, a global `require`\nfunction is available to all sandboxed JavaScript that provides many of these\nfunctions. Values can be read from the window with the\n[`copyFromWindow`](/tag-platform/tag-manager/templates/api#copyfromwindow) utility.\n| **Note:** `copyFromWindow` creates a deep copy of the values, and it can be an expensive operation to pass those values into and out of the sandbox.\n\nSimplified type system\n----------------------\n\nSandboxed JavaScript supports the following types: `null`, `undefined`,\n`string`, `number`, `boolean`, `array`, `object`, and `function`. Arrays and\nobjects are created using the literal syntax ( `[] {}` ), and because there's no\naccess to the standard global execution environment, global constructors like\n`String()` and `Number()` aren't available. There is no `new` keyword in\nsandboxed JavaScript, and functions do not have access to the `this` keyword.\nSome native type methods have also been removed. See [standard library](/tag-platform/tag-manager/templates/standard-library) for an\nexhaustive list of supported native type methods.\n\nCustom template code format\n---------------------------\n\nThe code written to implement a custom template represents the body of a\nfunction that will be executed whenever your tag is fired or your variable is\nevaluated. This function has a single data parameter (`data`) that holds all the\nvalues configured in the UI for that tag or variable instance, with the keys set\nto the names of the template parameters specified in the custom template.\n\nSample beacon tag implementation\n--------------------------------\n\n const sendPixel = require('sendPixel');\n const encodeUri = require('encodeUri');\n const encodeUriComponent = require('encodeUriComponent');\n\n let url = encodeUri(data['url']);\n\n if (data['useCacheBuster']) {\n const encode = require('encodeUriComponent');\n const cacheBusterQueryParam = data['cacheBusterQueryParam'] || 'gtmcb';\n const last = url.charAt(url.length - 1);\n let delimiter = '&';\n if (url.indexOf('?') \u003c 0) {\n delimiter = '?';\n } else if (last == '?' || last == '&') {\n delimiter = '';\n }\n url += delimiter +\n encodeUriComponent(cacheBusterQueryParam) + '=' + encodeUriComponent(data['randomNumber']);\n }\n sendPixel(url, data['gtmOnSuccess'], data['gtmOnFailure']);"]]
