RE: [xml-dev] What Does SOAP/WS Do that A REST System Can't?

["Dare Obasanjo" <dareo@microsoft.com>]

> -----Original Message-----
> From: Mark Baker [mailto:distobj@acm.org] 
> Sent: Thursday, March 31, 2005 7:34 AM
> To: xml-dev@lists.xml.org
> Subject: Re: [xml-dev] What Does SOAP/WS Do that A REST System Can't?
> 
> To keep it simple, I'll just focus on GET.  The "verify", 
> "check", and "determine" actions you mention above all seem 
> to map well to it.
> 
> Using SOA, with separate "verify", "check", and "determine" 
> operations, in order to get the resulting data from those 
> actions in the hands of a single client component, that 
> component has to be developed with support for all three 
> operations.  If a new "get me data"-like operation is added, 
> which isn't "verify", "check", or "determine", then that 
> client needs to be upgraded to support it too.
> 
> Using the uniform interface, a client need only support the 
> GET operation in order to retrieve data from all services, 
> past, present, and future.

I think I finally understand this. Let's use RSS feeds as an example. So
all the data we'll consider is in the RSS format. In an SOA model I'd
have a getSearchResults() service to get RSS feeds from Feedster, a
getRecentBlogPosts() service to get RSS feeds from the average blog and
a getRecentNews() service to get RSS feeds from a news site which
clients can support. If later on a a new service shows up (e.g.
getRecentBookmarks() to get RSS feeds from del.icio.us) then the client
has to be upgraded. 

However, since on the Web we actually use HTTP GET for fetching RSS
feeds, the fact that some new use of RSS shows up doesn't mean people
like me have to rewrite clients to support them [modulo supporting
extensions to RSS]. 

It took a while to figure what the uniform interface argument was about
but now I think I get it. 

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