On 20 September 2010 01:40, Roger Hågensen <[email protected]> wrote: > > > It would be better to define this as explicitly indicating which resources > are NOT valid any longer, > with most sites/web applications this would only be a select few links.
> I like the idea though as it'll allow a page to tell the browser that "Oh > BTW! If you happen to have this link cached, it was last updated on ...... > You might wanna re-check that if you got a older copy, despite what the > cache copy's expire is." > These extra attributes hopefully allow both kinds of validation; both "still valid despite being apparently invalid" and "now invalid, despite being apparently valid." In the first case it functions as a performance optimisation (a conditional-GET request that would result in a 304 is saved), and in the second case it actually prevents a page from rendering using an old resource (that it would not have validated). > Some thought need to be given to this though. This will only be same domain > right? If not then it could be partly used for a DoS. (if a popular site is > compromised and changed to link to a ridiculous amount files on other sites > it could get nasty right?) > I'm not sure I understand what you're saying, but my first reading suggests that this isn't a problem. These proposed attributes will only cause extra network requests in one case, that of a <link> to a cached resource which is still valid, but the <link> contains etags/last-modified which suggests it needs to be validated. Isn't this incredibly minor compared to all the other ways a resource can reference & include other pages? - Gavin
