Class: TrackRelay::ClientId::Ga

Inherits:
Object
  • Object
show all
Defined in:
lib/track_relay/client_id/ga.rb

Overview

Resolver that extracts the GA4-shaped ‘client_id` from the host app’s ‘_ga` cookie.

Default position-0 entry in TrackRelay::Configuration#client_id_resolvers. Reproduces Phase 01’s ‘_track_relay_client_id_from_cookie` parser bit-for-bit so existing behavior is preserved when the resolver chain is enabled.

## ‘_ga` cookie format

The ‘_ga` cookie ships with format `GA1.<version>.<random_int>.<unix_ts>` (four dot-separated segments). The GA4 Measurement Protocol expects the client_id to be the last two segments joined with a dot — e.g. cookie `“GA1.2.860784081.1732738496”` yields client_id `“860784081.1732738496”`.

The parser always takes the last two segments (‘parts`) rather than the 3rd/4th, so it is robust against:

- Custom server-side cookie writers that prepend extra segments
- Future Google rollouts that change the prefix segment count

Cookies with fewer than four segments are treated as malformed and yield ‘nil` (callers should fall through to the next resolver in the chain).

Instance Method Summary collapse

Instance Method Details

#call(controller:) ⇒ String?

Returns the parsed GA4 client_id, or ‘nil` when the cookie is missing/empty/malformed.

Parameters:

  • controller (#request) —

    any object exposing ‘controller.request.cookies`. Typically an `ActionController::Base` instance from TrackRelay::ControllerTracking#_resolve_client_id.

Returns:

  • (String, nil) —

    the parsed GA4 client_id, or ‘nil` when the cookie is missing/empty/malformed.



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# File 'lib/track_relay/client_id/ga.rb', line 37

def call(controller:, **)
  ga_cookie = controller&.request&.cookies&.[]("_ga")
  return nil if ga_cookie.nil? || ga_cookie.empty?

  parts = ga_cookie.split(".")
  return nil if parts.size < 4

  "#{parts[-2]}.#{parts[-1]}"
end