How do I limit collection for authenticated pages in an SPA?

[mdmower-csnw]

The getting started guide says...

Beyond sign-in pages, implementation of the DAP code on authenticated pages is permitted on a case-by-case basis only. Email the DAP team at dap@gsa.gov to request their approval and coordinate the prerequisite tests.

For an SPA (single page application), where the script loads once, is there any way for me to make DAP aware of paths where collection should not occur?

[mdmower-csnw]

I still hope to get a response from a maintainer, but for any other users that stumble upon this question...

I'm able to work around this issue by setting window[`ga-disable-${gtag_id}`] = true; prior to navigating to authenticated-only pages and window[`ga-disable-${gtag_id}`] = false; when navigating to anonymously accessible pages. The GTag ID can be one of two values, depending on whether dap-dev-env is set, so a small lookup helps:

function findGtagId() {
  for (const script of document.scripts) {
    // https://github.com/digital-analytics-program/gov-wide-code/blob/1817f8a53949c98953ec6b6015135c686805c99d/Universal-Federated-Analytics.js#L91
    if (script.src.startsWith('https://www.googletagmanager.com/gtag/js?id=')) {
      const id = new URL(script.src).searchParams.get('id');
      if (id) return id;
    }
  }
}

And specifically for React, if your private routes are wrapped by a component, a single useEffect hook can both disable and reenable analytics when the component is mounted and unmounted, respectively:

  useEffect(() => {
    const gtagId = findGtagId();
    if (!gtagId) return;

    window[`ga-disable-${gtagId}`] = true;
    return () => {
      window[`ga-disable-${gtagId}`] = false;
    };
  }, []);

The analytics documentation makes it sound like this approach wouldn't work since it is set after GTag has loaded, but in practice, it does seem to work fine for SPAs.

Aside: the approach that I thought would work...

function gtag(){dataLayer.push(arguments);}
// does not work
gtag('set', { 'send_page_view': false });

... does not work. In this case, I believe it is because history change events cause the page view events to be sent, and that process doesn't appear to check this setting prior to collection.