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[-2..]) 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).

Class Method Summary collapse

Instance Method Summary collapse

Class Method Details

.from_request(request) ⇒ String?

Extract and parse the _ga cookie from a request-like object.

Parameters:

  • request (#cookies, nil) —

    any object exposing request.cookies["_ga"] (e.g. an ActionDispatch::Request).

Returns:

  • (String, nil) 


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# File 'lib/track_relay/client_id/ga.rb', line 56

def self.from_request(request)
  parse(request&.cookies&.[]("_ga"))
end

.parse(cookie_value) ⇒ String?

Parse a raw _ga cookie value into a GA4 client_id.

This is THE canonical _ga parse rule — the resolver chain (#call) and the browser-proof delivery gate (Subscribers::Ga4MeasurementProtocol#prepare) both delegate here so the "fewer than four segments = malformed = nil" posture is defined exactly once.

Parameters:

  • cookie_value (String, nil) —

    raw _ga cookie value

Returns:

  • (String, nil) —

    the parsed GA4 client_id, or nil when the value is missing/empty/malformed.



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# File 'lib/track_relay/client_id/ga.rb', line 42

def self.parse(cookie_value)
  return nil if cookie_value.nil? || cookie_value.empty?

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

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

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["_ga"]. 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 66

def call(controller:, **)
  self.class.from_request(controller&.request)
end