In HTTP, the self-description is the MIME type declared in the HTTP header. Standard MIME types (i.e., registered types) describe the type of content (image, text, XML, etc), but they typically don't provide semantic information, such as what's in the image, what's in the text, or what's in the XML.
As I indicated in an earlier response to this message, I argue that the qualified name of the root element in a SOAP Body is a much more descriptive self-description than a MIME type. You can create your own MIME types, and in fact define a MIME type for an OASIS UBL document or a private schema negotiated out of band. I haven't looked it up, but I'd guess that EDI standard documents are, in fact, registered MIME types. The probelm with creating your own MIME types is that standard web clients don't know how to process them. One of the main reasons why the Web works is that MIME types are standardized, and all web clients know what to do when they get a JPEG in response to a GET. But what are they supposed to do with a privately defined MIME type? Anne On 2/26/07, Dennis Djenfer <[EMAIL PROTECTED]> wrote:
Jan Algermissen wrote: On 25.02.2007, at 22:55, Eric Newcomer wrote: Jan, In that case I would expect WebSphere MQ to be compatible with the Web since it has a uniform interface. Correct? Messaging systems have a uniform interface[1], yes. I am not sure what you mean by 'compatible' though. Messaging systems are a different kind of architectural style than the Style of the Web is. Following one of REST's constraints doesn't make a style the REST style. The Pipe and Filter style ( e.g. Unix shells) for example employes a uniform interface, too. But that style is not the Web style either. Do massaging systems constrain the messages to be self descriptive (do they require the payload to be of standardized formats)? Message self-descriptiveness is also one of the very important one of REST's constraints. Hi Jan, It seems like you're saying that a message is self descriptive if it's standardized, right? I'm curiouse about your defintion of a self-descriptive message: Is an order message that follows a schema that has been defined by OASIS UBL self-descriptive? Is an order message that follows a schema that has been negotiated out-of band between many organizations in a specific business domain self-descriptive? Is an order message that follows a schema that has been negotiated out-of band between two organizations self-descriptive? Is an EDI message that follows a structure that has been defined by an EDI standard organization self-descriptive? // Dennis Jan [1] You can of course also abuse those to tunnel commands Eric ----- Original Message ---- From: Jan Algermissen <[EMAIL PROTECTED]> To: [email protected] Sent: Sunday, February 25, 2007 2:53:27 PM Subject: Re: [service-orientated-architecture] SOA Pizza Order Surprises Eric, your posting 'deserves' a more detailed reply, so sorry for only sending a short comment (I still have a pile of work on my desk for tonight). On 25.02.2007, at 18:23, Eric Newcomer wrote: It is just hard to believe that the lack of uniform interfaces in SOAP and WSDL is the cause of all the disconnect with the Web. The lack of a uniform interface (the plural doesn't really make sense here, does it?) is contrary to the architectural style of the Web. That is just an undebatable fact. An architecture that does not employ a uniform interface can never be of the REST style and an architecture that does not specifically constrain itself to HTTP's set of methods on all objects is necessarily disconnected from the Web. Jan (And, yes, GET /foo/lauchMissile is not HTTP's GET, it is tunneling the launchMissile invocation through GET) ------------------------------ Bored stiff? <http://us.rd.yahoo.com/evt=49935/*http://games.yahoo.com> Loosen up... Download and play hundreds of games for free<http://us.rd.yahoo.com/evt=49935/*http://games.yahoo.com> on Yahoo! Games. ------------------------------ No virus found in this incoming message. Checked by AVG Free Edition. Version: 7.5.446 / Virus Database: 268.18.4/702 - Release Date: 2007-02-25 15:16
