UriTemplates with a Custom WCF 4.5 WebHttpBehavior

Question

I'm implementing a custom WCF REST behavior, it implements/overrides the base WebHttpBehavior but allows for REST communication using a custom serializer. The code is based on Carlos' work here.

I've got it running but the thing is we REALLY want to use the UriTemplate functionality to allow for true REST-ful URIs. Has anyone seen this done or could provide help on finding the right implementation?

We're sticking with WCF on purpose to provide REST and SOAP endpoints at the same time so moving to Web API is not an option here.

Answer 1

The problem may just be that the example is slightly outdated. Also, the implementation class, NewtonsoftJsonBehavior, is explicitly overriding and throwing an InvalidOperationException within the Validate(ServiceEndpoint endpoint) method.

Using Carlos' example, remove the validation:

public override void Validate(ServiceEndpoint endpoint)
{
    base.Validate(endpoint);

    //TODO: Stop throwing exception for default behavior.
    //BindingElementCollection elements = endpoint.Binding.CreateBindingElements();
    //WebMessageEncodingBindingElement webEncoder = elements.Find<WebMessageEncodingBindingElement>();
    //if (webEncoder == null)
    //{
    //    throw new InvalidOperationException("This behavior must be used in an endpoint with the WebHttpBinding (or a custom binding with the WebMessageEncodingBindingElement).");
    //}

    //foreach (OperationDescription operation in endpoint.Contract.Operations)
    //{
    //    this.ValidateOperation(operation);
    //}
}

Add a UriTemplate to GetPerson or other method:

[WebGet, OperationContract]
Person GetPerson();

[WebGet(UriTemplate="GetPersonByName?l={lastName}"), OperationContract(Name="GetPersonByName")]
Person GetPerson(string lastName);

Within the Service class, add a simple implementation to validate that the arguments are parsed:

public Person GetPerson(string lastName)
{
    return new Person
    {
        FirstName = "First",
        LastName = lastName, // Return the argument.
        BirthDate = new DateTime(1993, 4, 17, 2, 51, 37, 47, DateTimeKind.Local),
        Id = 0,
        Pets = new List<Pet>
        {
            new Pet { Name= "Generic Pet 1", Color = "Beige", Id = 0, Markings = "Some markings" },
            new Pet { Name= "Generic Pet 2", Color = "Gold", Id = 0, Markings = "Other markings" },
        },
    };
}

In the Program.Main() method, a call to this new URL will parse and return my query string value without any custom implementation:

[Request]
SendRequest(baseAddress + "/json/GetPersonByName?l=smith", "GET", null, null);

[Response]
{
"FirstName": "First",
"LastName": "smith",
"BirthDate": "1993-04-17T02:51:37.047-04:00",
"Pets": [
{...},
{...}
}

Answer 2

I had started going down the road of implementing my own UriTemplate parsing/matching logic, but then I stumbled upon this answer (Using Custom WCF Body Deserialization without changing URI Template Deserialization) and found it did that and more.

In order to use it, you still have to uncomment the code related to validating that a UriTemplate is not used. I also ended up reformatting the code a bit for my purposes (taking out logic to check if there was more than one parameter, since in my use case the body would always be exactly one parameter).