Inject a javascript value into datalayer key value

Question

I'm trying to add an event ID to my website pages (WordPress site) so I can use it to generate an "event ID" for Enhanced eCommerce events that I push to google tag manager to avoid the same event being counted twice from the server and browser to GA4 and facebook.

I'm using the function

function event_id() {
eturn 'xxxxxxxx.xxxx.4xxx.yxxx.xxxxxxxxxxxx'.replace(/[xy]/g, function(c) {
var r = Math.random()*16|0, v = c == 'x' ? r : (r&0x3|0x8);
return v.toString(16);
});

to generate a unique ID, after that, I want to inject its value in the 'event id' as you can see below :

window.dataLayer = window.dataLayer || [];
window.dataLayer.push({
'event': 'page_id',
'event_id': 'event_id'
};

please some help

Answer 1

I suggest using a Community Template which generates an event ID as a variable for you: https://tagmanager.google.com/gallery/#/owners/stape-io/templates/unique-event-id-variable

This way it's not in the dataLayer but as a variable which you can then access in your other tags, e.g. facebook/meta.