Slides from MeasureCamp NA 20203: this session is less about the "why" and more about "how" to replace gtag. walker.js is a great tool for tagging with full control of what will be sent where. You will get an overview of what walker.js is, how it works, and a live demo how to… - run GA4 using client-side and server-side GTM - send data to alternative tools or - directly to BigQuery

1. Markus Baersch
Replacing gtag.js with walker.js
Why? How?
Demo: Running GA4 Using ssGTM

3. Why Not GTAG.JS?
(yes, same old song - but only a very brief summary. And a new color! Yay!)

4. gtag.js
some issues
(shortened version)
Source: likely to be blocked
Heavy: UA, GA4, GAds, Optimize,
partner badges + stuff
Not a “Stream To Rule Them All”:
no data without consent.
Consent Mode is not an option!

5. gtag.js
… is odd!
(also shortened version)
GA4 Session Handling & More:
● “first_visit” and “session_start”
● Conversions
● referral exclusion
● public measurement id

6. Options:
● ga4mp.dev by David Vallejo (->
ssGTM)
● Build your own format and send
to own endpoint Or use existing
tools like CDPs, Tealium (see
slides from MC Berlin 2022)
But:
● Blocking might still be a problem
● Costs?
● Control?
Alternatives exist!
perfect fit?

7. Feeding GA4 with walker.js

8. Open source: walker.js is a maintained
repo on GitHub
(Can) have all data you need: there
are timestamps, timings, hit
numbers…
https://github.com/elbwalker/walker.js
elbwalker
open source event tracker

9. Tagging Basics
uses a command / event queue
called “elbLayer” (per default)
scans DOM for data-elb attributes
and builds events and parameters
alternatively push events to
elbLayer manually via JavaScript
can send events to several
destinations
Destinations are consent sensitive
(walker.js can handle consent) https://github.com/elbwalker/sgtm-client-template/tree/main/example

10. events have an “open” structure to
contain default attributes, custom
attributes, session state, user
information, references… or whatever
Send example:
elb('page view',
{id: '/test/virtual/path1',
title: 'Virtual Page 1'},
'click',
{some_property: 14}
);
Events

11. Sending Stuff: walker.js Destinations
Every destination can handle events individually. We use it to send data to a ssGTM endpoint

12. GA4 Session Handling
GA4 wants session handling
(simple) example…
- is only active if consent is
present
- uses localStorage /
sessionStorage - which is
only possible on a single
domain AND host
- Can be part of destination
init block (see example code
for ssGTM tag)
elb("walker user",
{hash: sD.sessionId,
device: sD.clientId});

13. Tagging: GTM Tag Template
github.com/elbwalker/gtm-tag-template
Custom Templates for walker,js
Configuration
and walker,js Events to migrate
GTM setups
- destinations
- GA4 session data
- ecom item conversion
- use your existing variables

14. Endpoints
● use ssGTM and translate walker events to ssGTM event model
○ trigger / fire any tags as if gtag.js did generate all requests
● or build your own in Node, PHP or whatever and forward events to
GA4
○ cloud edge endpoints actually are an option ;)
● Remember: CNAME is not an option to avoid browser tracking
protection issues

15. ssGTM Example
use custom client for walker events
basic example and client template
available on Github:
github.com/elbwalker/
sgtm-client-template
-> fork and build what you need
(contribute if you like!)

16. send data to GA4 using
standard tag
enrich server-side
dimensions
add debug flag for
better debugging (kill
before publishing ;))
ssGTM Example

17. … or send data
(additionally or
exclusively) to Piwik
PRO, Matomo…
… or send directly to
BigQuery as
event-level raw data
ssGTM Example

18. Demo
sending events…
… from client-side GTM…
-> to ssGTM
-> to GA4
Medium article:
mbaersch.medium.com/
A-better-solution-for-ga4-
Data-capturing-replacing-
gtag-js-with-walker-js-
2b9fd291d919

19. No ssGTM? Use: worker for walker events
forward (few data) to GA4 using GAMP V2
think: add event to D1 cloud database ;)
Or build your endpoint as
- AWS Lambda
- GCP Cloud Function
- Azure Function
Cloud Functions & Workers

20. Can you see it?

21. Done!
Questions?

22. Game On!
download and play:
Walker | GTM Tags | Client | BQ:
github.com/elbwalker
Order:
markus-baersch.de/gtmbook