GTM Tag Template

The walkerOS tag template is part of the GTM stack. It allows easy integration of walker.js into a website. Once set up, a single walkerOS tag can load walker.js on all website pages via GTM. Besides it's own configuration, destinations and on-events can be registered.

Setup

The walkerOS tag template creates a new tag type in Google Tag Manager (GTM) that allows you to load walker.js on your website easily. Download and import it once:

Download GTM Tag Template

info

The walkerOS tag template is currently in review for the official GTM Template Gallery. In the meantime, it can be imported manually.

To install the walkerOS tag template, follow these steps:

Download

Click Download GTM Tag Template to go to the official source and click the Download raw file.

Step 1

In Google Tag Manager, navigate to Templates on the left and click on New in the Tag Template section.

Step 2

Click on the three dots and Import option. Select the previously downloaded walkerOS_tag_template.tpl file and click the Save button.

Step 3

Now you can create a new Tag and select the walkerOS tag template from the Custom section.

Installation

There are multiple ways to load walker.js on a site.

Load walker.js

CDN

This option loads the walker.js script from an external source (jsDelivr). It's good for quick testing but refers to an external domain. A version can be specified. It's recommended to use a specific version starting from 2.1.0

Self-hosted

Save and upload the index.browser.js to your server for first-party context and minimize requests to external domains.

The GTM is very restrictive about loading third-party scripts. To load walker.js from a custom domain, update the Tag Template Permissions and add YOUR_DOMAIN to the Injects scripts section.

Window (recommended)

A more advanced but recommended approach is to integrate walker.js without fully loading another file. This reduces the total file size and the number of requests for better performance. The Tag template creates an instance using the available factory in the browser window.

import { Walkerjs } from '@elbwalker/walker.js';
window.Walkerjs = Walkerjs; // Make it globally available

Mode

There are three modes to start walker.js:

1. Auto run: starts automatically when the tag fires.
2. Require consent: waits until the consent state is granted before calling walker run. This uses the walker on command internally.
3. Manual: won't do anything - it's up to you.

Names

The default names can be changed to prevent eventual conflicts with other scripts or existing variables. Ensure the template's Permissions are updated to enable read/write access to the new names.

Options

Tagging version

Specifying a tagging version helps manage and debug a setup by knowing the version used during measurement. After changing the setup, increase the version number.

User ID

This will set the user.id value based on a variable. Both device and session IDs will be set in the Session section or via a custom on-event.

Globals

Add static globals that will be added to every single event.

Logging

Enabling the preview adds a destination that logs all events to the console.

Session

Session detection, user identification, consent management, and race conditions are closely connected. Learn more about how to detect a session.

Enabling session detection will use the sessionWindow Util as a cookie-less version to eventually trigger a session start event.

Additionally, enabling the Storage uses the sessionStorage Util to persist data and enhance session information and user identification. As this might require consent, it's possible to add a Required consent for storage access.

This uses elbDeviceId and elbSessionId in the localStorage. There is a virtual rule to limit the age to 30 days for the device ID and 30 minutes for a session ID, which updates with each new run.

Destinations

Destinations are used to send events to other systems. Using dataLayer will automatically send all events to the GTM dataLayer.

To add a destination, the Code is required, while Config is optional.

Add destination

Both Code and Config are User-Defined Variables. A destination code can be some custom JavaScript or a pre-build version. The config is a simple object that can be used to configure the destination.

Code (Custom)

Create a new or load a User-Defined Variable with the Custom JavaScript type and add the following code:

function(){
  return {
    type: 'my-destination',
    init: function(config) {
      console.log('Setting up my destination', config);
    },
    push: function(event, config, mapping) {
      console.log('My destination', event, config, mapping);
    }
  }
}

Write your code instead of the console.log statements.

Code (Pre-build)

Available web destinations have a special ES5-build that can be used in the GTM.

1. Go to the destinations page and click the  ES5 button at the top to get the pre-build code.
2. Copy the whole code and create a new User-Defined Variable with the Custom JavaScript type.
3. Paste the code within the following code block:

function(){
  // Paste the pre-build code here

  return Destination.default;
}

The return Destination.default; is case-sensitive and must be added at the end.

Config

Create a new or load a User-Defined Variable with the Custom JavaScript type and add the following code:

function(){
  return {
    // Common config like
    // loadScript: true,
    custom: {
      // Destination specific config like
      // measurementId: 'G-XXXXXXXXXX'
    }
  }
}

This will return a simple config object.

On Events

On-events, listen to specific Trigger to execute Code. Use a User-Defined Variable with the Custom JavaScript type to create a Code function.

Read more about how to use the on events in general.

On consent

Get's called when a walker consent command changes a matching state.

The code has to be an object with the consent state as the key and the function as the value.

function() {
  return {
    functional: console.log,
    marketing: function (instance, consent) {
      console.log('Marketing', consent);
    }
  }
}

Only if functional or marketing stages change, the corresponding function will be called.

elb('walker consent', { foo: true }); // Won't trigger any function
elb('walker consent', { functional: true, marketing: false }); // Calls both functions

Typically, a Consent Management Platform will call the walker consent command with the consent state.

On run

Get's called with each walker run command:

function() {
  return function (instance) {
    console.log('On run');
  }
}

Hooks

Hooks can be used to customize the default behavior of walker.js. A hook can be called before ( preHook ) or after (postHook) a specific event and runs a custom function defined in a User-Defined Variable. Each call signature is the same as the original function, see the  walker commands .

Create a new User-Defined Variable with the Custom JavaScript type and return the function within a js-code block:

// Code for the preHook function
function () {
  return function(params, event, data, options, context, nested) {
    /// custom code
  }
}

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Learn more about the individual  function signatures.