HTTP GET requests (was Re: SOAPAction Proposal)

* Noah Mendelsohn <Noah_Mendelsohn@lotus.com> [2001-05-04 17:16-0400]
> Just to be clear, although I am indeed intrigued regarding the possibility 
> of encoding a SOAP request in a URI, probably in conjunction with an HTTP 
> GET, it probably would be at best only sometimes be the right thing to do. 
>  In other words, an alternate HTTP binding, or maybe an option on the core 
> binding.  Also:  I saw a discussion a few weeks ago among some URI experts 
> who pointed out that long URI's are somewhere between discouraged and 
> forbidden.  I think that's really too bad based on the (0, 1, arbitray) 
> view of limits, but there it is.

The ability to do an HTTP GET request for an XMLP/SOAP message is IMO
an important issue that we have to discuss.

The axioms of the Web architecture[1] state that:

1/ In HTTP, anything which does not have side-effects must use GET.
 If I am using a service which tells me the temperature in Tokyo, I
 might want to use an HTTP GET request for this request, send my
 friends the URI so that they can get the same information, and
 get (HTTP) caching for free, since it is likely to be the same 5
 minutes later.

2/ In HTTP, GET must not have side effects.
 The situation is different if I deposit money on my account.
 Dereferencing the URI a second time will not be the same: I really
 want to have the same amount deposited again. In such a case, GET
 would not be appropriate.

I am not really sure how we would encode a SOAP request into the query
component of the URI without ending with a 2 page-long URI, as Noah
pointed out. Whether this would be an issue, I don't know. I would
appreciate a pointer on the discussion about the length of URIs.

Note that HTTP POST requests[2] can also be cached:

   Responses to this method are not cacheable, unless the response
   includes appropriate Cache-Control or Expires header fields. However,

In any case, either we find a way to do so, or we will need to talk
to Tim about this part of the Web architecture document[1].

I think that we should log this as an issue.

  1. http://www.w3.org/DesignIssues/Axioms.html#state
  2. http://www.w3.org/Protocols/rfc2616/rfc2616-sec9.html#sec9.5
-- 
Hugo Haas - W3C
mailto:hugo@w3.org - http://www.w3.org/People/Hugo/ - tel:+1-617-452-2092

Received on Monday, 7 May 2001 04:49:23 UTC