I have front-end GA4 implementation and want to send transactions data (and some custom events) from the server via MP. With recomendations of Google to
include session_id as a param, so that measurement protocol events appear in session-based reporting
is it better to get session_id from gtag.js or generate random session_id?
I think I found the solution here https://www.optimizesmart.com/what-is-measurement-protocol-in-google-analytics-4-ga4/#11-10-session-id-
There 2 params in the request to GA:
According to Measurement Protocol (Google Analytics 4)/Sending events using random value for 'session_id' parameter will start new session.
According to Measurement Protocol (Google Analytics 4)/Changelog 'session_id' is required to get server-side events in session-based reports.
Solution:
'Session Id' is stored in cookies and seems it's a timestamp of session start date. To get 'Session Id' at server side using PHP:
/**
* Gets GA Session Id (GA4 only) from cookies.
*
* @var string $measurement_id
* GA4 Measurement Id (Property Id). E.g., 'G-1YS1VWHG3V'.
*
* @return int
* Returns GA4 Session Id or NULL if cookie wasn't found.
*/
function _get_browser_session_id($measurement_id) {
// Cookie name example: '_ga_1YS1VWHG3V'.
$cookie_name = '_ga_' . str_replace('G-', '', $measurement_id);
if (isset($_COOKIE[$cookie_name])) {
// Cookie value example: 'GS1.1.1659710029.4.1.1659710504.0'.
// Session Id: ^^^^^^^^^^.
$parts = explode('.', $_COOKIE[$cookie_name]);
return $parts[2];
}
}