- From: Clemm, Geoff <gclemm@Rational.Com>
- Date: Fri, 25 Feb 2000 09:16:51 -0500
- To: w3c-dist-auth@w3.org
Every concept is referenceable, so your definition would make the term "resource" a synonym for the term "concept". This makes the term "resource" useless, since the term "concept" is well defined, and adding a synonym for it does not buy us anything. An alternative definition is that a resource is a function that can be associated with a URI, where the input to this function is a method name, a request URI, a list of headers, and a request body, and the output is a list of headers and a response body. (I pretty much copied this definition from one of your earlier posts, so I make no claim of originality here). In this alternative definition, all sorts of concepts are not resources ... in particular, a method name is not a resource, a header is not a resource, a request or response body is not a resource, and a URI is not a resource. I believe this alternative definition is far more useful for defining a binding protocol. I'm willing to use some other term for this alternative concept, if it is important to reserve "resource" as a synonym for "concept", but my impression is that this alternative definition is the more commonly accepted one. Cheers, Geoff > -----Original Message----- > From: Roy T. Fielding [mailto:fielding@kiwi.ICS.UCI.EDU] > Sent: Friday, February 25, 2000 12:17 AM > To: Clemm, Geoff > Cc: Slein, Judith A; w3c-dist-auth@w3.org > Subject: Re: Qualities of URLs and resources > > > >There are some concepts that explicitly are not resources, > >e.g. the concept of a "URI" or the concept of a "property". > > Nope. If the concept is referenceable, it is a resource. If you ask > me for the URL that I was using to represent my home page in 1994, > you are referring to a URI as a resource in itself. All properties > are resources -- DAV just defines a different way of accessing them > than the old HTTP interface. The only reason it did so is because > some people felt that adding direct access to properties was better > than paying for one round trip. > > >Like URI's and properties, a binding is not > >something that is identified by a URI, and is not something > >to which you can apply requests. Instead, a binding > >is just a term we use to talk about how a collection > >resource behaves, e.g. if at time T, a collection resource has a > >binding named "foo" to a resource with DAV:resourceid "xxx", then > >this is just a shorthand for saying that a > >depth:1 PROPFIND at time T on any URL that is mapped to that > collection > >will return a DAV:response with a DAV:href whose value is > >"<that URL>/foo" and with a DAV:resourceid whose value is "xxx". > > > >In other words, all URI's that are mapped to that collection at time > >T will have a member named foo, and the DAV:resourceid of that member > >will be "xxx". > > For any concept X, it is possible to create an identifier namespace > obeying the requirements of RFC 2396 such that concept X is > unambiguously > identified within the scope of the namespace's usage. It is therefore > possible to identify any concept with a URI, which makes it a > resource. > > BTW, DAV:resourceid is an abomination. It breaks the implementation > abstraction that is at the core of the Web interface. Telling server > implementors to reveal that information is wrong and is completely > unnecessary to define the protocol. > > ....Roy >
Received on Friday, 25 February 2000 09:29:17 UTC