The Écran Large code tracks clicks on the subscription link
A script handles tracking and validation of the subscription button in the interface.
The script detects the .cta button and, as soon as a user clicks, it sends a tracking event named `google_preferred_source_click` with the URL, link text and domain. If no destination is set, the button becomes disabled, its `aria-disabled` attribute is set to "true" and a tooltip appears. The code saves the scroll position and body styles before closing the dialog, then restores them to avoid any page jump. According to Écran Large, the mechanism ensures that the subscription link only works when a valid URL is provided.