PWA cache enhance

[Mister-Hope]

I think we should not cache html by default. (Only cache home page and 404)

Several reasons:

• Don't have any effect when installed.

  Homepage is the PWA entrance.
  Homepage, 404 with all js can work offline.

• Slow upgrading

  In previous versions of chrome, all requests are triggered. So pwa updates only takes seconds.

  Butas this may block other request, so staring from a Chrome version ( likely between 78 - 80), service worker request is triggered one by one.

  This means users may wait more than 1 minute to see the new content ( for v2 docs on netlify, 2 and a half minite for me with out VPN and 70s under VPN)

  And if they are just quick searching, they may not notice they are reading a historical version.

  (And it can be worse if they just close the browser before the PWA finish upgrading. If a new version lands before they open next time, they will never get an update )

  If not cache html, they can see the actual version through direct visiting and if the service work is the newest, after loading the html, everythign will then come from service worker, and no more loadtime.

  Also a refresh should be okey for users to see new contents even if they entered through homepage.

@meteorlxy WDYK?

This is the default behaviour for my v1 pwa plugin, and it works fine.

[meteorlxy]

Also noticed that the PWA updated slowly.

It would be nice if omitting other html files could work fine.

Curious about what will happen if users visit a non-cached html file (e.g. '/guide/') offline? Will it fallback to the homepage?

[Mister-Hope]

Just showing offine.

I think this can be omitted. If people installs PWA as an app, they will always start from homepage when entering it.

[Mister-Hope]

Addtional: It seems that you can configue workbox-build to provide an offine page, noticing people to go to homep age. Or just use homepage as the offine content.