[whatwg] In AppCache web apps, images from unpredictable domains won't load

Ian Hickson ian at hixie.ch
Mon Jul 20 15:20:18 PDT 2009

On Mon, 6 Jul 2009, Aaron Whyte wrote:
> When a page is loaded from an AppCache, even when online, external 
> resources such as images will not be loaded at all. If foo.com has an 
> image <img src="http://bar.com/img.png" />, then according to the steps 
> in 
> http://www.whatwg.org/specs/web-apps/current-work/multipage/offline.html#changesToNetworkingModel 
> it will fail the load for the resource.

Right; an app is intended to be self-contained, such that if it uses a 
manifest, and has been tested and shown to work (even while online), it is 
more or less guaranteed that it will work offline.

> For example, someone with an Offline Gmail client would never be able to 
> see cross-domain images in emails, even when completely online.

Good point, an app that shows uncached externally-sourced content is going 
to have trouble with the closed-sandbox model.

On Mon, 6 Jul 2009, Aaron Boodman wrote:
> I think we could fix this issue by simply changing the rules to default 
> to allowing requests, and having the author mark the url prefixes he 
> wants to blacklist from being loaded from the network.

On Mon, 6 Jul 2009, Michael Nordman wrote:
> That would work too. We'd have to introduce a new kind of 'namespace' in 
> the manifest file.

I've made it so that you can specify "*" in the online whitelist section 
to basically open it up to anything.

Ian Hickson               U+1047E                )\._.,--....,'``.    fL
http://ln.hixie.ch/       U+263A                /,   _.. \   _\  ;`._ ,.
Things that are impossible just take longer.   `._.-(,_..'--(,_..'`-.;.'

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