- From: David Woolley <forums@david-woolley.me.uk>
- Date: Sun, 16 Jun 2013 12:10:02 +0100
- To: public-sustyweb@w3.org
Looking at iSkeleton Framework, linked from your wiki, I can't help but feel that it is an over-designed solution to a problem that could be better handled by proper use of the caching features in HTTP/1.1. They assume that images will be revalidated ever time, but if one cares about bandwidth, one will set up clients** and ISP proxies to revalidate only as needed and set long expiry times on the images, on the server. It can, in any case, only properly be used for cosmetic content, as its use of primary content will break the semantics of the HTML, which I believe is bad in principle, but also means that, for instance, Google Images will not work for the site. Where it is used in graphic controls, my first reaction would be to to seriously question the need for these, but if really needed, I believe that it is possible to clip part out of a larger image, client side. I think Google's Page Speed site refers to this as CSS sprites. This should remove the need to do low level manipulation of the image date in interpreted code. Possibly the most common reasons for images to fail to cache is the tendency of people to set cookies on every single resource. This has no real benefit for market research purposes, or in targeting advertising, and certainly none for the end user, but defeats caching. (It can also make sites painful if one wants to be selective in the cookies one is prepared to accept.) There is probably a whole topic about the negative effects of cookies on resource usage and their lack of benefit to consumers. One of the reasons for poor use of caching features is that HTTP setting are often managed by an IT department, whereas content authoring is normally a marketing responsibility. Also students can practice with HTML/CSS/DOM/JScript more easily than they can with setting up web servers. ** This appears to be the default in Firefox, although well hidden, and, in some versions, only available via about:config (browser.cache.check_doc_frequency=3). -- David Woolley Emails are not formal business letters, whatever businesses may want. RFC1855 says there should be an address here, but, in a world of spam, that is no longer good advice, as archive address hiding may not work.
Received on Sunday, 16 June 2013 11:10:29 UTC