Concept course

JavaScript for GTM

Just enough JavaScript to stop waiting on developers: variables and types, arrays and objects, the two places GTM runs your code, reshaping data for GA4, writing event listeners, and scraping the DOM safely.

Start lesson 18 short lessons · reading · self-paced

Syllabus

1
Why A Tagger Needs JavaScript
The point where the GTM UI runs out, and code begins.
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2
Values, Variables & Types
Strings, numbers, booleans, and why types bite you.
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3
Arrays, Objects & Loops
The data shapes GA4 ecommerce is built from.
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4
Where GTM Runs Your Code
Custom JS variables vs Custom HTML tags.
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5
Reshaping Data For GA4
Adapting a messy dataLayer to vendor requirements.
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6
Writing Event Listeners
Catching interactions GTM doesn't track by default.
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7
DOM Scraping, Safely
Reading values off the page without breaking it.
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8
Using AI, And Verifying It
Go faster with AI without shipping hallucinated code.
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