[whatwg] Enhancement request: change EventSource to allow cross-domain access

Per-Erik Brodin per-erik.brodin at ericsson.com
Sat Jun 18 15:25:57 PDT 2011

On 2011-06-17 21:57, Ian Hickson wrote:
> On Wed, 1 Jun 2011, ilya goberman wrote:
>> Can EventSource be enhanced to support cross-domain requests via
>> "Access-Control-Allow-Origin" header, just like it is already done for
>> XHR? See
>> http://en.wikipedia.org/wiki/XMLHttpRequest#Cross-domain_requests.
> Done.

Great news!
The same-origin check in step 4 under "When the EventSource() 
constructor is invoked .." is still present.

According to the CORS specification, a request is not to be terminated 
even when the resource sharing check fails. However, when using CORS 
with EventSource I think it may be justified since the response is 
typically not returned right away.

The Cache-Control request header used with EventSource is not in the 
list of simple request headers and a preflight request is not really an 
option here in my opinion.


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