[css3-images] Indicating it's optional to retrieve a url specified in background-image (or font-face)

Jason Grigsby and Guy Podjarny have each done research into the page
weight of responsive designs and have found that at smaller
resolutions page weight doesn't currently decrease for many sites.

The page weight is generally going to be an issue for phones, tablets
etc due to their limited memory, processor speed etc. but it's at the
network level where I think it really becomes an issue especially when
connected via a lower throughput cellular network.

I've been researching various means of detecting whether someone is
connected via a cellular network and during this process came to the
conclusion that perhaps what we need is a way of indicating external
resources can be optional i.e. at lower throughputs the UA can choose
not to download them, but can use them if they are already cached.

Background images and font-face are the obvious candidates for an
optional property e.g.

   background-image: image('wavy.png') optional;

Not quite sure whether this works though:

    background-image: image('wavy.svg', 'wavy.png' , 'wavy.gif') optional;

Also not sure whether a single optional property is the right way to
go, or at what throughput level it actually would kick in but I'd be
really interested in others thoughts.

Cheers

Andy

Received on Wednesday, 4 July 2012 20:00:51 UTC