993716 - [tarako] Lazy load Fira Sans webfonts

Status: RESOLVED FIXED

(Marketplace Graveyard :: Consumer Pages, defect, P1)

Description

[Christopher Van Wiemeersch [:cvan]]

I don't want to add Fira Sans to the appcache manifest if it's already on the device.

Unfortunately, there's a Firefox bug that fetches all font-families even when a fallback isn't necessary (bug 881924 / bug 754215).

Additionally, there are two other bugs preventing src:local from working on Firefox OS + Firefox for Android (bug 754215, bug 769194).

(See bug 991419 for details.)

If these platform bugs can't be fixed, if Fira Sans is not installed, we can add the @font-face blocks and lazy-load the fonts in. I came up with an awesome way of detecting if a font's installed: https://github.com/cvan/fontinstalled

Until then, I'm removing Fira Sans from appcache manifest.

Comment 1

[Jonathan Kew [:jfkthame]]

(In reply to Christopher Van Wiemeersch [:cvan] from comment #0)
> I don't want to add Fira Sans to the appcache manifest if it's already on
> the device.
> 
> Unfortunately, there's a Firefox bug that fetches all font-families even
> when a fallback isn't necessary (bug 881924 / bug 754215).
> 
> Additionally, there are two other bugs preventing src:local from working on
> Firefox OS + Firefox for Android (bug 754215, bug 769194).

Bug 769194 is fixed on trunk, which means src:local should work, which in turn means that you can use a @font-face rule that lists multiple sources, with src:local first, and src:url(...) following that; the url will only be downloaded if the local lookup fails.

While it would be nice to fix bug 754215 as well, that's not essential here now that you can use src:local to "shadow" the downloadable fonts.

Comment 2

[Christopher Van Wiemeersch [:cvan]]

I already fixed this:

https://github.com/mozilla/darjeeling/commit/ff9eed7
https://github.com/mozilla/darjeeling/commit/d96439a

Comment 3

[Jonathan Kew [:jfkthame]]

(In reply to Christopher Van Wiemeersch [:cvan] from comment #2)
> I already fixed this:
> 
> https://github.com/mozilla/darjeeling/commit/ff9eed7
> https://github.com/mozilla/darjeeling/commit/d96439a

I think you need to modify the src:local lookups in this commit; see comments I've added on github.