Just to be a little more explicit...
> > 3) Are these files always needed when offering a web service via SOAP? You are never required to provide a WSDL file. But if you want to "offer" this service (and by "offer" I assume that you intend to make it avilable to a variety of clients) then you need to provide technical information to these clients about how to use the service. A WSDL file provides a complete technical description of your web service. It describes - what the web service does (the operations that the service supports, and the messages (including type information) that must be exchanged for each operation) - how to communicate with the service (which protocol(s) it supports, whether you're using RPC style or document style, and how the messages are encoded) - where to find the service (it's access point) If you don't provide a WSDL file, then you'll need to provide this technical specification in some other way (perhaps a written document describing how to use the service or perhaps via a telephone conversation.) The advantage of providing a WSDL file is that most SOAP toolkits now have the ability to generate a client interface from the WSDL file. Otherwise clients will have to construct these interfaces by hand. Most SOAP toolkits (Systinet WASP, .NET, IBM WSTK, Apache Java2WSDL, etc.) now provide tools to generate WSDL from your server code. You usually don't need to write the WSDL by hand. If you're using a tool that doesn't generate WSDL, then I recommend that you use a WSDL editor tool such as Omniopera (www.omniopera.com) to help you write it. Then look at lots of sample WSDL files to guide you. The biggest source or errors in WSDL files come from errors in namespace usage. As a best practice, always qualify all of your element names. Keep these thoughts in mind: - your default namespace should be the WSDL namespace (the namespace that defines the <definitions>, <types>, <message>, <portType>, <operation>, <service>, and <port> elements. Any element or attribute that you use that's not in this namespace needs to be qualified. - your target namespace is not the same as your default namespace. To reference elements defined in your WSDL file, you should define a tns: namespace that points to your target namespace. Regards, Anne Thomas Manes CTO, Systinet www.systinet.com
