- From: Mark S. Miller <erights@google.com>
- Date: Thu, 8 Dec 2011 15:00:37 -0800
On Thursday, December 8, 2011, Jonas Sicking wrote: > On Thu, Dec 8, 2011 at 9:23 AM, Mark S. Miller <erights at google.com<javascript:;>> > wrote: > > Given only that the JSONP response has a ACCESS-CONTROL-ALLOW-ORIGIN:* > > header, the API you suggest below can be fully implemented as a library. > > > > Since any response that parses as JavaScript has no same origin > protection > > anyway, rather than carve out a special case for JSONP, should we waive > > the ACCESS-CONTROL-ALLOW-ORIGIN:* requirement on responses that parse as > > JavaScript for XHR requests in general? If not, what justifies carving > out a > > special case for JSONP? > > There's two *possible* reasons to treat JSONP special. > > The weak reason would be to support existing JSONP-serving servers > which are out there already. JSONP appears to be one of the more > popular formats for HTTP-based APIs right now. > > The stronger reason is that it appears that people have a very hard > time setting http headers. While this seems surprising to me, > especially in situations like this where you already have server-side > scripts generating dynamic content, it is feedback that I get *a lot*. > > Another option would be some way to express CORS signals inline in > content. This actually existed in early CORS drafts, but only for XML > based contents which made it a lot less appealing. Especially since > the XML based content had to be served with a proper Content-Type > header which puts us back at square one. > My suggestion is that if the response parses as a JavaScript Program, this is interpreted as an inline signal, since same-origin protection for these responses make no sense. The reason why you're willing to carve out a special case for JSONP is precisely because these responses, parsing as JavaScript, are not protected by same-origin. > > / Jonas > -- Cheers, --MarkM
Received on Thursday, 8 December 2011 15:00:37 UTC