Dynamic invocation of web services?

[Generic Usenet Account]

Most of the open source web-service products that I am reading about seem to require generation of client stub and server implementation ancestor classes from the WSDL file. The client application links in with the stubs. Like CORBA SII, the client operates on a proxy (albeit a "service proxy" and not an "object proxy") in its address space.

This approach seems to limit the scope of web services. Is there an equivalent of CORBA DII for web services? I believe the UDDI standard allows clients to invoke services without having compile-time knowledge of the service description. Is this correct? Also, are there any open source web-service products that support this capability?

Thanks in advance.

Bhat

 

[Zahid Faizal]

Most of the open source web-service products that I am reading about seem to require generation of client stub and server implementation ancestor classes from the WSDL file. The client application links in with the stubs. Like CORBA SII, the client operates on a proxy (albeit a "service proxy" and not an "object proxy") in its address space.

This approach seems to limit the scope of web services. Is there an equivalent of CORBA DII for web services? I believe the UDDI standard allows clients to invoke services without having compile-time knowledge of the service description. Is this correct? Also, are there any open source web-service products that support this capability?

Thanks in advance.

Bhat

The web-services specifications do not preclude the possibility of "dynamically" discovering the description of a service and then binding to it, although hardly any of the C++ products that I have looked at support that capability.

Having said that, I must admit that I feel that the whole notion of "dynamically" discovering the description of a service and then binding to it is, like CORBA DII, a pipe-dream. Yeah, you can make it work in some "toy" applications, but the feasibility of this approach, in the real world, is questionable. Many times I wish that DII and dynamic service description discovery were merely described as the means towards reducing integration time and effort. Remember, unless you have the "business logic" to process a response from a service/interface regarding which you had no compile time knowledge, you cannot get very far and all you can come up with is a "Toy Story".

--ZF