The analytics.js script doesn't load offline

[philipwalton]

Library Affected:
sw-google-offline-analytics

This library currently stores the analytics.js script in cache, but due to CORS restrictions, the script fails to load for offline requests (except in cases where it's already in the browser's HTTP cache).

A short term fix is to have users host the analytics.js script themselves. In the longer term, it'd be nice to either add CORS support to analytics.js or change the way <script> tags handle opaque responses in service worker cache.

I'm looking into the long-term solutions.

[addyosmani]

A short term fix is to have users host the analytics.js script themselves.

Are there any gotchas to them self-hosting?

[philipwalton]

No big gotchas; here are the primary downsides I see:

• When you self-host you don't get updates/bug fixes.
• When you self-host you miss out on the fact that visitors to your site likely already have the analytics.js script in their cache (since it's used on so many sites on the internet).

[jeffposnick]

On further investigation, it is actually working when served from the cache, as <script> resources don't require CORS.