- From: Kornel Lesinski <kornel@geekhood.net>
- Date: Tue, 31 Jul 2007 20:51:15 +0100
- To: "Philip Ronan" <philronan@blueyonder.co.uk>
- Cc: "public-html@w3.org" <public-html@w3.org>
On Tue, 31 Jul 2007 18:22:41 +0100, Philip Ronan <philronan@blueyonder.co.uk> wrote: > (1) A web page providing instructions on how to download an image might > contain the following: You could use Content-Disposition header and simply link to an image. > (2) A web page that contains a few characters of Japanese will not > display correctly IMHO a better approach would be to embed a custom font that contains these characters and set it as last alternative in CSS. > (3) A website with user-selectable CSS stylesheets could use a cookie to > store the client's preferred style and set this stylesheet as the > default stylesheet for subsequent page views. I think this would be better solved if UAs simply remembered user's choice of alternate stylesheet. However for this and similar customizations, you could use HTML5's client-side storage: http://www.whatwg.org/specs/web-apps/current-work/multipage/section-storage.html > According to the HTTP specification (RFC2616), content that varies in > this way should include a Vary header. So in case (1), the server should > flag the page with the HTTP header "Vary: User-Agent". Unfortunately, > this would make it almost pointless caching the content Although Vary header doesn't work, it's not the only possible way. You can use Cache-control: private to avoid polluting public caches with customized pages and use E-tag for cache validation of different versions. > <OBJECT selector="User-Agent" match="Macintosh"> > Click on the image while holding down the <B>Control</B> key, The problem is, there are a lot more platforms and browsers than average webmaster could even name (including "Macintosh-that-supports-right-mouse-button" ;) and it would be nearly impossible to support them all in that way. A different, platform-agnostic approach would be easier for webmasters and better for users of OS/browser combinations that aren't in top 2. If instructions for saving an image were important, it could be <img for-saving> or <help show="how-to-save-an-image">. -- regards, Kornel Lesinski
Received on Tuesday, 31 July 2007 19:51:35 UTC