Passing MetaData between services

I’ve got some C# code that returns a Metadata object from DocMan service, and I need to use this in my custom service as a Metadata object, Visual Studio thinks that DocMan.Metadata is not the same as MyService.Metadata and also won’t allow casting between the two. I’ve noticed that the Collaboration service has its own Metadata object and so when added VS gives me one in MyService, DocMan and Collaboration.

How do I copy one Metadata object to another ?

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Greg_Griffiths

I've noticed that CollaborationService:Service:Collaboration:_SetSignature includes :

        { \
             "CreateDiscussion", "Create a discussion.", \
             { \
                 { "DiscussionInfo discussionInfo", "DiscussionInfo object holds create information for the discussion" } \
             }, \
             "DocMan.Node", "Returns the created discussion." \
         }

but when I set the following in my service, contrived example below to convey meaning, Visual Studio does not like it :

         { \
             "DoStuff", "does stuff.", \
             { \
                 { "Integer DataID", "Data ID of the Node we want to do stuff to" }, \
                 { "DocMan.MetaData", "The Cats and Atts of the Node we need to use for DoStuff" } \
             }, \
             "Boolean", "Did the stuff work ?" \
         }

my C# code looks like :

node TemplateNode = docman.getNode( auth, 1234)
metadata TemplateNodeMetaData = TemplateNode.Metadata

result = myService.DoStuff(1234, TemplateNodeMetaData)

sgrasley

Hi, Greg.

WCF proxies put each web service (and its schema) into a separate namespace, so from C#'s point of view, they are different classes. I believe the only solution is to implement code to clone the object from one namespace to the other, property by property. This is why there are different instances of OTAuthentication for each service.

There are some other solutions mentioned on the Web, but they involve linking the proxies with the implementation classes somehow, if memory serves.

JAX-WS proxies do not have this behaviour, and they use the same class for the same schema in different services, which can have its own challenges...

Thanks,

Scott

Greg_Griffiths

Scott,

Thanks for the update, we are writing a conversion function at the moment, can we ask that in the next release there is a simple method to do this a la ToString ?

sgrasley

Hi, Greg.

Unfortunately, this is a limitation with WCF itself, so it's not something that we can control.

Thanks,

Scott

Greg_Griffiths

Scott,

Thanks for the update, can you explain how the following works given the above :

CollaborationService:Service:Collaboration:_SetSignature

It appears as though a Collaboration WebService is returning a DocumentManagement WebService node, is that correct ? If so can a similar thing be done with MetaData i.e. have MyService accept a DocMan.MetaData rather than a MetaData ?

sgrasley

Hi, Greg.

Yes, the same schema is used for the Node SDO between both the Collaboration service and the DocumentManagement service. However, when Visual Studio generates a WCF Service Reference for each service, the proxies are in separate namespaces, which is why you run into difficulties passing the objects from one service to another client side. As far as the client is concerned, they are two different classes, even though they are the same structures on the server side.

JAX-WS client proxies behave differently, so the same schema in different services is represented by the same class, so you can pass a Node from Collaboration to DocumentManagement.

Again, this is a client-side limitation with WCF.

Thanks,

Scott