[gcs-pcs-list] more comments (plain text)

[Daniel Chudnov]

Eric Hellman wrote, on Mon, Mar 06, 2006 at 12:23:45PM -0500:
> 
> What I'm observing is that there are two types of requests made to an 
> unAPI service
> ...
> 2. request for metadata object

A quick point of information:  unAPI makes no functional distinction
between objects and metadata objects.  The same functions may refer
to requests for either, relative to the same URI, and nothing in unAPI
itself specifies which is which.


> What I'm saying is that responses to (1) should ALWAYS return xml if 
> the unAPI service is working, and I shouldn't have to care about http 
> status codes. Responses to (2) should be possible to delegate to an 
> http stack, or to a browser, or whatever.

This is worth discussing, so:

What is the benefit of an xml response on a 404, like you suggest:

  <formats>
    <uri>info:foo/bar</uri>
  </formats>

There is nothing you can do with that that a 404 doesn't already tell
you.  Indeed, if it is a restricted-access item, you will get more 
information from a 401 or 403 status code, also, than just examining
this echoed response.  Version 0 suggested echoing http status codes
into the response entity format itself; this was voted down by consensus
as the information is already present in the HTTP headers if appropriate
codes are used.

Your preference for implementing unAPI with an XML handler-centric
processing technique doesn't change the fact that the HTTP functions in
unAPI are an HTTP convention, not an XML protocol. :)

  -Dan


-- 
Daniel Chudnov
Yale Center for Medical Informatics
(203) 737-5789