I have two WCF services I am adding reference to in my application. Both these services have an object called X, which is the same object.
The problem is after adding the references in my application, I am getting two different objects, with the same exact structure, but with different namespace.
This prevents me from casting between them and forces me to create two different objects, one for each service.
Please notice I don’t want to use dll’s.
Please notice I don’t want to use dll’s.
You'll have to. When you generate a WCF proxy, you have the option to reuse types from referenced assemblies. This have to be assemblies containing the types also used by the service. See also How to: Configure a Service to Reuse Existing Types.
Of course as #Franck pointed out in a comment, it's possible to intervene in the serialization process. You can also use a tool like AutoMapper.
More interesting is your actual problem: why don't you want to use a DLL reference? Did you try that but do you for example wish to deploy a single-file application, then merge the assembly in your executable.
Related
Can a web service use other classes that I have in a project or should it be standalone and use only it's own methods?
Thanks !
Does a web service can use other classes that I have in the project ?
YES it can. You can also return your custom class object, after serialization. Its very unusual that you would see webservice interacting with primitive types only (internally).
You can create instances of other classes and use them to perform work.
Any class in the same project or a referenced project should be usable, subject to the usual access modifiers.
You'll either need to include a using statement. Following example assumes you want to use SomeClass which resides in MyAssembly.SomeLibrary:-
using MyAssembly.SomeLibrary;
// in code block somewhere
var thing = new SomeClass();
or fully qualify the name of the class.
var thing = new MyAssembly.SomeLibrary.SomeClass();
It sounds like you are asking in terms of best practice rather than "is this technically possible". The answer depends on the class you want to use I suppose, but in general it is acceptable to use any other classes or libraries you want in a web service as this will not affect the client being able to consume the service (i.e. using LibraryA on the service side does not mean client 1 has to also have LibraryA installed to use your service).
It is possible to reuse those classes service side (in Visual Studio this is done by ticking the "Reuse types in referenced assemblies" box when you configure a service reference and then adding a reference to the appropriate project / dll), but I would generally advise against it as it can confuse matters - not all clients will have access to those dlls when consuming your service.
This is probably a real simple one. I wished to create some code inside a [DataContract] class which is used to communicate information between a WCF service and consuming application.
I created a new Portable Class Library project and created inside it my [DataContract] class. It's really simple - it has a few easy attributes (strings mostly). I added a reference to the DLL in my WCF service and republished it. I then deleted the service reference from my consumer project and re-added it. It adds fine, no problems there.
The problem comes when I want to actually use it. See, the type is called 'Eval'. Some of the WCF methods return this 'Eval' type. So I have this serialized version of 'Eval' in the Reference.cs file within my service reference. Obviously this doesn't contain the method I'm looking for since it's just the serialized version. I can add the dll to the client project as well, but then I have two different Eval objects in two namespaces, and only the one from reference.cs is valid to be returned from the service calls.
So how do I ... erm... merge the two? So as the Eval objects that come back from the WCF service calls also have access to the method in question?
Thanks for reading, and stay safe on those roads.
When generating service reference you can specify what classes should be reused and what classes should be generated from service
I have a client app consuming a WCF service that is accepting and returning some complex type parameters. these complex types are held in a separate assembly that both the client app and the WCF service are referencing..
the problem is that when I add the service reference in the client app, the generated reference class builds its own versions of the complex parameter types and hence I cant pass in the types from the assembly that the original types are defined.
not sure if that is at all understandable..
question is.. am I going to have to write some sort of reflective deep copy routine to effectively build up the service reference generated classes from the original types?
or is there a better option
any help as ever very happily received
nat
When you are adding a service reference to code, select Advanced and you'll see an option Reuse types in referenced assemblies. If you ensure that is checked, and the reference is added to the project, WCF won't generate the proxy types and use the referenced types instead.
If you've already added the service reference, reference your shared types first, and then right-click the Service Reference, and select Configure Service Reference to get it to regenerate the client code using your referenced types.
Nope, you can do it: see my question here:
WCF Service Reference generates its own contract interface, won't reuse mine
You can have a shared assembly with interfaces, types, and both the service and client(s) can reference it :)
The 'reuse referenced types..' option does cover complex types, but the answer above also covers reusing the interface type, which IMO is far better option and not covered by that VS option.
Unless I've misunderstood, by checking "Reuse types in referenced assemblies" in the Advanced settings within Add Service Reference, any data contracts which match those in a referenced assembly will be reused and not regenerated.
Consider the following Visual Studio project structure
ProjectA.csproj
AClass.cs
ProjectB.csproj
References
ProjectA
Web References
AWebService
AWebService.csproj
References
ProjectA
ReturnAClassViaWebService.asmx
The issue occurs when ProjectB adds the web reference to AWebService and automatically generates all the proxy code for accessing AWebService including a new implementation of AClass. Since all of our other code needs to use the AClass defined in ProjectA, we're forced to convert the AWebService.AClass returned from the service into something we can use.
We're currently considering two solutions, neither of which are ideal.
Manually editing the generated Reference.cs to remove new definitions of AClass
Serializing AWebService.AClass to a stream then deserializing to ProjectA.AClass
Does anyone have any better solutions? This seems like something common enough for other developers to have experienced it.
Ideally we would like to have the proxy code generated in ProjectB to reference ProjectA.AClass rather than generating a whole new implementation.
Our environment is VS 2008 using .NET 2.0.
I have had the same problem that you are describing and I have tried both of the options you specify without being entirely happy about either of them.
The reason we both have this issue is at least partly because the shared-library-between-consumer-and-provider-of-a-web-service-solution is in violation of accepted patterns and practices for web service design. On the consumer side, it should be sufficient to know the interface published in the WSDL.
Still, if you are prepared to accept a tight coupling between your web service provider and web service consumer and you know for certain that your current client will never be replaced by a different client (which might not be capable of referencing the shared library), then I understand why the proposed solution seems like a neat way to structure your app. IMPORTANT NOTE: Can we really honestly answer yes to both of these questions? Probably not.
To recap:
The issue appears when you have classes (e.g. a strongly typed dataset) defined in some sort of shared library (used on both client and server).
Some of your shared classes are used in the interface defined by your web service.
When the web reference is added there are proxy classes defined (for your shared classes) within the web reference namespace.
Due to the different namespaces the proxy class and its actual counterpart in the shared library are incompatible.
Here are four solutions that can be tried if you want to go ahead with the shared library setup:
Don't. Use the proxy class on the client side. This is how it is intendend to be done. It works fine unless you simultaneously want to leverage aspects of the shared library that are not exposed by the web service WSDL.
Implement or use a provided copy/duplication feature of the class (e.g. you could try to Merge() one strongly typed dataset into another). A Cast is obviosuly not possible, and the copy option is usually not a very good solution either since it tends to have undesirable side-effects. E.g. When you Merge a dataset into another, all the rows in the target dataset will be labeled as 'changed'. This could be resurrected with AcceptChanges(), but what if a couple of the received rows were actually changed.
Serialize everything - except for elementary data types - into strings (and back again on the consumer side). Loss of type safety is one important weakness of this approach.
Remove the explicit declaration of the shared class in Reference.cs and strip the namespace from the shared class wherever it is mentioned within Reference.cs. This is probably the best option. You get what you really wanted. The shared class is returned by the web service. The only irritating drawback with this solution is that your modifications to the reference.cs file is lost whenever you update your web reference. Trust me: It can be seriously annoying.
Here is a link to a similar discussion:
You can reuse existing referenced types between the client and service by clicking on the 'Advanced' button on the 'Add Service Reference' form. Make sure the 'Reuse types in referenced assemblies' checkbox is checked and when the service client is generated it should reuse all types from project A.
In past versions this has not always worked correctly and I've had to explicitly select the shared type assemblies by selecting the 'Reuse types in specified referenced assemblies' option and then checking the appropriate assemblies in the list box. However, I just tested this with VS 2008 SP1 and it appears to work as expected. Obviously, you need to make sure that the types that are being used by the service and client projects are both from project A.
Hope that this helps.
We encountered a similar problem with one of our projects. Because we had several dependencies, we ended up creating a circular reference because project 1 required objects from project 2, but project 2 could not be build before project 3, which relied on project 1 to be build.
To solve this problem, we extracted all the public standalone classes from both projects and placed them inside a single librarie. In the end we created something like this:
Framework.Objects
Framework.Interface
Framework.Implementation
WebService
The WebService would be linked to all projects in our case, whereas external parties would only be linking to the objects and interface classes to work with. The actuall implementation was coupled at runtime through reflection.
Hope this helps
In my client, I'm trying to declare an entity type from the service....
MyService.MyClass myClass = new MyService.MyClass();
....
MyClass isn't available.
The assembly MyClass is within is referenced by MyService. What am I missing?
Generally, to preserve the service boundary, you work with mex-generated proxy classes at the client; these are structure only, so don't have any methods etc (just properties), and may even have different names (and almost certainly a different namespace).
However; if this .NET to .NET, you can get WCF (via either svcutil or the IDE) to re-use types in existing assemblies. Via the IDE it does this automatically (by default - you can disable it) if you have a reference to a dll containing matching types. At the command line, you use /r IIRC.
From the client's perspective, the service is just the interface, the client doesn't have access to the guts of the server. The types you might need should be exposed as part of a contract externally (like in a seperate assembly).
You probably want to Add Service Reference. Note that the generated class will have a slightly differnt name/namespace to your server implementation.