Zubair.NET!

WCF Service Contract and XML Serialization

2009-08-09T07:13:00Z

I am building a Service using the WCF REST Starter Kit. This Service contains a method that accepts a complex type as input, it then deserializes the object into it’s concrete type.

Here’s how a service call looks like

using (HttpClient client = new HttpClient())
{
    RequestObject req = new RequestObject { FirstName = "John", LastName = "Doe", Email="johndoe@somecompany.com"};

    HttpContent body = HttpContentExtensions.CreateXmlSerializable<RequestObject>(req);

    HttpResponseMessage resp = client.Post("http://localhost:1575/Web/Service.svc/SendMail", body);

    Response.Write(resp.Content.ReadAsString());
}

What the above does is simply prepare a RequestObject, call a SendMail method on the service using the HttpClient, read and print the response, nothing fancy.

Here’s how the service looks like

[WebHelp(Comment = "Sample description for SendMail")]
[WebInvoke(BodyStyle = WebMessageBodyStyle.Bare, RequestFormat =
WebMessageFormat.Xml, ResponseFormat = WebMessageFormat.Xml,UriTemplate = "SendMail")]
[OperationContract]
public RequestObject SendMail(RequestObject request)
{
    return new RequestObject()
    {
        FirstName = request.FirstName, LastName = request.LastName,Email = request.Email
    }; 
}

Notice what I’m doing is preparing the same RequestObject and simply pass it as the response.

As you’d expect I’m suppose to get the following response in the browser.

- <RequestObject>
  <FirstName>John</FirstName> 
  <LastName>Doe</LastName> 
  <Email>johndoe@somecompany.com</Email> 
</RequestObject>

But the response I receive is similar to this

<RequestObject>
    <FirstName i:nil="true" />
    <LastNameName i:nil="true" />
    <Email>johndoe@somecompany.com</Email>
</RequestObject>

After a few hours of trying it occurred to me that XML Serialization is done in the alphabetical order if no ordering is specified even if the properties in the class are not in the alpha-order. (arrgh. If only I had used the Paste XML as Type as demo’ed in this screencast by Aaron Skonnard)

So to make it work I had to change the RequestObject class in both places to look like the following.

public class RequestObject
{
    public string Email { get; set; }
    public string FirstName { get; set; }
    public string LastName { get; set; }
}

VS 2010 Beta 1 and Functional UI Testing

2009-05-14T11:55:00Z

I just watched a video over at Channel9 which explains how to leverage some of the UI Testing capabilities that are going to be introduced with VS 2010 beta 1 expected next week.

Visual Studio had testing capabilities for C# code for a long but now I’m glad to see for the first time an integrated UI testing built right into VS 2010 IDE. In particular I like the option to store the tests in the database and be able to run them automatically.

See it for yourself, there is also a Mix09 video here

Return JSON objects the right way

2009-04-29T08:12:54Z

Today I experienced a weird behavior when I was passing JSON string back to a jQuery call using an Ajax-enabled WCF Service.

My code looked something like this.

     [OperationContract, WebGet(ResponseFormat = WebMessageFormat.Json, UriTemplate = "/GetJson")]

    public string GetJson()

    {

        return new JavaScriptSerializer().Serialize(MyCustomObject)

    }

The problem with above code is that the string returned is escaped and enclosed with inverted commas that for some reason was not handled properly using jQuery that looked like this.

“[{\"Id\":1,\"SomeKey\":\"SomeMoreText\"}]”

Not sure what I was missing and while there is a JsonResult action in ASP.NET MVC with a .svc there’s nothing that I could use (or may be there is).

To fix it I changed the method like this.

    [OperationContract, WebGet(ResponseFormat = WebMessageFormat.Json, UriTemplate = "/GetJson")]

    public System.IO.Stream GetJson()

    {

       byte[] resultBytes = System.Text.Encoding.UTF8.GetBytes(new JavaScriptSerializer().Serialize(MyCustomObject));

       WebOperationContext.Current.OutgoingResponse.ContentType = "application/json";

       return new MemoryStream(resultBytes); 

    }

Here’s how Json is returned.

[{"Id":1,"SomeKey":"SomeMoreText"}]

Don’t use UriTemplate = "/MethodName/Param1/{Param1}/Param2/{JsonObject} for Json input with WCF Service

2009-04-12T12:58:00Z

When building Ajax-enabled WCF service that expect a Json object as input then the following would not work

     [OperationContract, WebGet(ResponseFormat = WebMessageFormat.Json, UriTemplate = "/Methodname/jsonvariable/{jsonvariable}/param2/{param2}")]

    public void MethodName(string jsonvariable, string param2)

    {

    }

Where jsonvariable is a json object passed through jQuery (or ASP.NET Ajax) to a WCF service that looks like this

[{"Name":"za","Email":zubairdotnet@hotmail.com}]

After spending a while I figured out that the following UriTemplate should be used instead

    [OperationContract, WebGet(ResponseFormat = WebMessageFormat.Json, UriTemplate = "/Methodname/?jsonvariable={jsonvariable}&param2={param2}")]

    public void MethodName(string jsonvariable, string param2)

    {

    }

Using Regular Expressions to Rename Textbox IDs

2009-01-07T06:30:28Z

How can you use regular expression in Find and Replace in Visual Studio to use the Textbox IDs same as your Column name in the Eval statement?

Consider the following two textboxes and there are couple of textboxes like them in the form

     <cmpst:Textbox ID="txtAppNo" Text='<%#Eval("AppDate") %>' runat="server" />

    <cmpst:Textbox ID="txtAppNo" Text='<%#Eval("NIN") %>' runat="server" />

You want to convert the IDs of the above textboxes as following

    <cmpst:Textbox ID="txtAppDate" Text='<%#Eval("AppDate") %>' runat="server" />

    <cmpst:Textbox ID="txtNIN" Text='<%#Eval("NIN") %>' runat="server" />

I took me a while to get this regular expression right, so I'm posting it here for reuse, here's how

Find

    ID=\"txt(.*)\" Text=\'\<\%\#Eval\(\"{(.*)}\"\)
  

Replace

    ID="txt\1" Text='<%#Eval("\1")
  