RE: [uddi-spec] V4 Discussion Item - approach to defining data structures and interfaces

From
"Uon Qiegen, Dlaus"
Date
2003-03-20T14:27:20+00:00
ID
4B8422D300DD314CA8F52F2F4A7F268401253624@dewdfx12
Thread
RE: [uddi-spec] V4 Discussion Item - approach to defining data structures and interfaces
Title: Message

Actually, I am not sure if I got John's idea.

Is it 
all about the general V3 approach to include as many syntactical restrictions in 
the UDDI XML schemas?

The 
example Matthew is talking about is one of several occurences in the UDDI API 
XML schema where we specified an OR logic with XML schema. Since XML schema 
directly only supports XOR logic with its "choice" feature, we were forced to 
use an implicit OR logic (one or more description elements OR one 
overviewURL element in the example).

 

There 
are many issues w.r.t. "complete" XML schema support in tools/frameworks but I 
don't know how a separation of the syntactical restrictions from the UDDI 
schemas (and perhaps a textual specification instead) would help the mapping to 
programming interfaces.

 

Claus

 

-----Original Message-----
From: Matthew Dovey 
[mailto:] 
Sent: Mittwoch, 19. M酺z 2003 
13:52
To: John Colgrave; 

Subject: RE: [uddi-spec] V4 Discussion 
Item - approach to defining data structures and interfaces

> I think the time is approaching when programming 
interfaces for UDDI will

> be

> able to be generated automatically from the UDDI 
WSDL descriptions.  I

> think

> we should take this into account when designing and 
describing the UDDI

> data

> structures and programming 
interfaces.

 

I'd support this.

 

I had (naively) assumed that it would have 
been possible to generate the programming interfaces for UDDI from the WSDL 
(naively assuming that this was supposed to be one of the benfits of WSDL!). 
Certainly as the interface becomes more complicated, I'd argue that this is 
essential if we want to see take up of UDDI.

 

In practice, I've find it difficult to 
generate the API's using the existing published WSDL and the Axis java based 
toolkit. A major problem has been unsupported XML Schema types in the Axis 
toolkits. At the last attempt Axis 1.1 beta I think that there was one 
unsupported type which I had to hack around. The problem at the moment (although 
I've not tried the latest Axis 1.1 Rc2 yet) is when we hit structures of the 
form

 

 

The Axis toolkit would generate code of 
the form

 

String description[];

String overviewURL;

String overviewURL;

 

(the first overviewURL being from the 
first part of the choice within the sequence, and the second from the second 
part of the choice).

 

I can't speak for other toolkits (so this 
may be a peculiarity of Axis) or for the recent 1.1 RC2. In some of the other 
WebService work, I've been involved with we have gone out of the way to make 
sure that ther structures are such that the WSDL does pass through as many 
toolkits as possible (in some cases at the expense of concise XML in the opinion 
of some of the designers).

 

Matthew