Skip to content

feat: add support for ga4 cross-domain measurements #21

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Open
filiphsps wants to merge 1 commit into
base: master
Choose a base branch
from
Open

feat: add support for ga4 cross-domain measurements #21

Show file tree
Hide file tree
Changes from all commits
Commits
Show all changes
1 commit
Select commit
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
7 changes: 7 additions & 0 deletions config/settings_schema.json
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -32,6 +32,13 @@
"default": false,
"label": "Multipass login",
"info": "If multipass is implemented the login will also redirect to your storefront [Learn more](https://shopify.dev/api/multipass)"
},
{
"type": "checkbox",
"id": "ga4_crossdomain",
"default": false,
"label": "GA4 cross-domain measurements",
"info": "Required to collect accurate attribution data from customers getting redirected by this theme [Learn more](https://support.google.com/analytics/answer/10071811?hl=en). For this to work you will need to have gtag.js loaded in <head> as a blocking script."
}
]
},
Expand Down
56 changes: 55 additions & 1 deletion layout/theme.liquid
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -208,7 +208,14 @@
}

window.storefrontRedirectUrl = redirectUrl;
window.location.replace(redirectUrl);

{%- comment -%}
When we're using the ga4 work-around, we'll have to patiently wait for gtag.js to complete
it's initialization.. so we will have to redirect later in the body.
{%- endcomment -%}
{%- unless settings.ga4_crossdomain -%}
window.location.replace(redirectUrl);
{%- endunless -%}
}
}
</script>
Expand All @@ -229,6 +236,53 @@
if (!window.Shopify.designMode) {
var redirectLink = document.getElementById("redirect-link");
redirectLink.href = window.storefrontRedirectUrl;
{%- if settings.ga4_crossdomain -%}
{%- comment -%}
Ugly but effect workaround for ga4 not properly (or kind of at all) programatically invoked
navigation events for cross-domain measurements.

We're esentially exploiting the fact that analytics try to "decorate" html forms when they
have an action that points to a domain included in the list that you've configured under
Data Streams -> Configure tag settings -> Configure your domains; in the analytics property
settings. See https://support.google.com/analytics/answer/10071811.

This code was originally written to fix cross-domain measurements the other way around, eg
between the headless frontend and the Shopify-hosted checkout for the e-commerce store
https://www.sweetsideofsweden.com. So you can repurpose this code to get proper cross-domain
measurements for you're checkouts too. :^)
{%- endcomment -%}
function getCrossDomainLinkerParameter() {
const form = document.createElement("form");
form.action = "https://{{ settings.storefront_hostname }}";
{%- comment -%}
Note, `opacity: 0` is deliberately used since the ga4 decorator wouldn't be or isn't able to
detect `display: none`
{%- endcomment -%}
form.style.opacity = "0";
form.addEventListener("submit", (event) => {
event.preventDefault();
});
const btn = document.createElement("button");
btn.type = "submit";
form.append(btn);
document.body.append(form);
btn.click();

{%- comment -%}
This could fail for a magnitude of reasons such as ad-blocking, invalid configuration, etc.
But when it doesn't fail, which is most of the times we get full complete cross-domain measurements.
{%- endcomment -%}
const _gl = form.querySelector("input[name=\"_gl\"]");
if (_gl) return _gl.value;
return null;
}

const ga4 = getCrossDomainLinkerParameter();
if (ga4) {
redirectLink.href += `${redirectLink.href.includes("?") && "&" || "?"}_gl=${ga4}`;
redirectLink.click();
}
{%- endif -%}
}
</script>
{%- else -%}
Expand Down