Re: Integrating XP Into Web Infrastructure

Perhaps I can help here, having debated this subject many times on many mail
lists over a couple of years.

The major benefit of using SOAP and XML-RPC is the compatibility you get
between various scripting and runtime environments. You could get something
similar with basic HTTP, but once you get beyond a few scalars you see the
advantages pretty clearly. It's simpler. If you didn't use XML to pass
complex structures, what would you use in its place?

I discount the concern about "companies with large and specialized servers
to sell" -- unless XP is a lot more complex than SOAP and XML-RPC, there
will be plenty of choices starting at no cost and pretty simple.

Dave


----- Original Message -----
From: "Kurt Cagle" <cagle@olywa.net>
To: "Aaron Swartz" <aswartz@upclink.com>
Cc: <xml-dist-app@w3.org>
Sent: Monday, January 08, 2001 6:07 PM
Subject: Re: Integrating XP Into Web Infrastructure


> I'd actually like to second this question. The obvious limitation of HTTP
> queries seems to revolve around datatypes, but that to me seems to be more
> an issue of system implementation -- in general, if you know the
parameters
> and their types to be passed, type becomes largely irrelevent (especially
if
> a mechanism exists for consistently converting a query string/POST request
> into an XML structure on the server side with an established schema map
> reference. To make an XML Server request through SOAP or similar
mechanisms
> I have to create an XML DOM, populate it, send it through a dedicated pipe
> function, while sending an HTTP request with query string parameters can
be
> done through a generic POST or QS method call. It's also worth pointing
out
> that XSLT has no mechanism currently for sending XML to a URI (though it
> will with XSLT1.1) but with a query string based web services interface
you
> could call a web service with a document function and incorporate the
> results directly into the processor stream.
>
> I worry that in our host to build RPC functionality through XML that we
> overlook simple solutions that do not add significantly to infrastructure
> overhead in favor of those that benefit companies with large and
specialized
> servers to sell.
>
> -- Kurt Cagle
> -- Author, XML Developer's Handbook
>
> ----- Original Message -----
> From: "Aaron Swartz" <aswartz@upclink.com>
> To: <xml-dist-app@w3.org>
> Sent: Monday, January 08, 2001 5:20 PM
> Subject: Integrating XP Into Web Infrastructure
>
>
> > I just finished reading the XP Reqs and I had a few questions about how
XP
> > would fit into the web infrastructure.
> >
> > It seems to be acknowledged a popular use of XP will be as a RPC
> mechanism.
> > However, other XML-based RPC protocols (XML-RPC, SOAP) have been
> criticized
> > because of their lack of URIs and misuse of HTTP. The major problem
seems
> to
> > be that information only available through some sort of RPC request
cannot
> > be given a URI (and thus cannot do any of the things that result from
> that).
> > Additionally, such systems use a single HTTP method (generally POST) and
> > thus muddy the semantic meaning behind an HTTP method.
> >
> > As an example, there is a SOAP stock price RPC where a SOAP envelope
> > containing a ticker symbols in responded by an XML message containing
the
> > stock price. Many argue that such a simple system should be implemented
> > using HTTP GET instead of SOAP.
> >
> > With that introduction, I have the following questions for the WG:
> >
> > 1) Do you feel that such RPC/HTTP services are "bad" and would you
> recommend
> > against their use with XP?
> >
> > 1a) If so, do you plan to structure XP in such a way that the negatives
of
> > such services are lessened?
> >
> > 2) Do you expect to preserve the semantics of HTTP requests (HEAD, GET,
> > POST, PUT) with the HTTP binding?
> >
> > 3) Do you have plans to attach a URI of some sort to an XP message? (It
> > seems that this would certainly ease use cases 805, 807 and 809
(Routing,
> > Tracking and Caching).)
> >
> > Thanks for information you can provide on this subject,
> >
> > --
> > Aaron Swartz <me@aaronsw.com>|           my.info
> >   <http://www.aaronsw.com>   |   <http://my.theinfo.org>
> > AIM: JediOfPi | ICQ: 33158237|  the future of news, today
> >
>

Received on Monday, 8 January 2001 21:54:42 UTC