All,
Will do my best to dial in but will be in a car (not driving) coming back from Virginia at the time.
On the Logical vs Physical REST bindings, instead of having logical HTTP bindings and physical bindings why not have an abstract, protocol independent, RESTful API based on the std REST operations on a resource of get current state, transfer state, modify intended state, remove state? One concrete realization of these bindings would be a mapping to HTTP GET, PUT, POST, DELETE respectively.
Some food for thought from Roy Fielding's blog 'Untangled':
"API designers, please note the following rules before calling your creation a REST API:
- A REST API should not be dependent on any single communication protocol, though its successful mapping to a given protocol may be dependent on the availability of metadata, choice of methods, etc. In general, any protocol element that uses a URI for identification must allow any URI scheme to be used for the sake of that identification. [Failure here implies that identification is not separated from interaction.]
- A REST API should not contain any changes to the communication protocols aside from filling-out or fixing the details of underspecified bits of standard protocols, such as HTTP’s PATCH method or Link header field. Workarounds for broken implementations (such as those browsers stupid enough to believe that HTML defines HTTP’s method set) should be defined separately, or at least in appendices, with an expectation that the workaround will eventually be obsolete. [Failure here implies that the resource interfaces are object-specific, not generic.]
- A REST API should spend almost all of its descriptive effort in defining the media type(s) used for representing resources and driving application state, or in defining extended relation names and/or hypertext-enabled mark-up for existing standard media types. Any effort spent describing what methods to use on what URIs of interest should be entirely defined within the scope of the processing rules for a media type (and, in most cases, already defined by existing media types). [Failure here implies that out-of-band information is driving interaction instead of hypertext.]
- A REST API must not define fixed resource names or hierarchies (an obvious coupling of client and server). Servers must have the freedom to control their own namespace. Instead, allow servers to instruct clients on how to construct appropriate URIs, such as is done in HTML forms and URI templates, by defining those instructions within media types and link relations. [Failure here implies that clients are assuming a resource structure due to out-of band information, such as a domain-specific standard, which is the data-oriented equivalent to RPC's functional coupling].
- A REST API should never have “typed” resources that are significant to the client. Specification authors may use resource types for describing server implementation behind the interface, but those types must be irrelevant and invisible to the client. The only types that are significant to a client are the current representation’s media type and standardized relation names. [ditto]
- A REST API should be entered with no prior knowledge beyond the initial URI (bookmark) and set of standardized media types that are appropriate for the intended audience (i.e., expected to be understood by any client that might use the API). From that point on, all application state transitions must be driven by client selection of server-provided choices that are present in the received representations or implied by the user’s manipulation of those representations. The transitions may be determined (or limited by) the client’s knowledge of media types and resource communication mechanisms, both of which may be improved on-the-fly (e.g., code-on-demand). [Failure here implies that out-of-band information is driving interaction instead of hypertext.]
There are probably other rules that I am forgetting, but the above are the rules related to the hypertext constraint that are most often violated within so-called REST APIs. Please try to adhere to them or choose some other buzzword for your API."
I think it's important to note that pure REST as Fielding defines it is very tied to hypertext. I think he means that it's tied to links and the ability to traverse them, but what he's said is hypertext. We probably will not have a purely REST API, but I think we should aim for as RESTful as possible given the constraints of the requirements we have already decided on for XRI and XDI.
=Bill.Barnhill
From: Drummond Reed [mailto:drummond.reed@cordance.net]
Sent: Wed 12/3/2008 8:22 PM
To: 'OASIS - XDI TC'
Subject: [xdi] Agenda: XDI TC Telecon Thursday 1-2PM PT 2008-12-04
***** NOTE THE NEW NUMBER FOR THIS TELECON ****
***** SAME AS THE NUMBER FOR THE XRI TC TELECON THAT FOLLOWS IT ******
Following is the agenda for the unofficial telecon of the XDI TC at:
Date: Thursday, 04 December 2008 USA
Time: 1:00PM - 2:00PM Pacific Time (21:00-22:00 UTC)
TO ACCESS THE AUDIO CONFERENCE:
Dial In Number: 571-434-5750
Conference ID: 5474
AGENDA
1) PROGRESS OF XRI GCS DELIMITER PROPOSAL
http://wiki.oasis-open.org/xri/XriThree/GcsDelimiter
2) NEW XRI XREF DELIMITER PROPOSAL
http://wiki.oasis-open.org/xri/XriThree/XrefDelimiter
3) LOGICAL VS. PHYSICAL REST BINDINGS
As awareness of XDI grows at the Higgins Project, there has been discussion
that the "logical REST binding" of XDI to HTTP(S) in which all messages are
POSTs does not take advantage of some of the caching and other scalability
features of "physical" REST, where GETs, PUTs, and DELETEs are used.
http://en.wikipedia.org/wiki/REST
We'll discuss whether we should define both "physical" and "logical" HTTP(S)
bindings.
---------------------------------------------------------------------
To unsubscribe from this mail list, you must leave the OASIS TC that
generates this mail. Follow this link to all your TCs in OASIS at:
https://www.oasis-open.org/apps/org/workgroup/portal/my_workgroups.php