Raw HTTP POST with WCF

(From an interesting thread in the MSDN forums…)

WCF does not support raw HTTP requests with the content-type ‘application/x-www-form-urlencoded’ (which is the content-type the browser sends when you hit ‘submit’ in a <form> element) out of the box unless you treat the request body as a Stream.

This makes sense if you consider that the same principle applies when returning data, as you can see here in the Picture Services sample, both the GetDocumentation() and GetPicture() operations return a Stream with data; all you need to do is set the content-type properly and you’re good to go.

I’ve created a little sample that shows how to POST data from a HTML form and parse it in WCF with a little help from the System.Web namespace.

Consider the following service contract:

[ServiceContract]
public interface ISampleService
{
    [OperationContract]
    [WebInvoke(UriTemplate = "invoke")]
    void DoWork(Stream input);
}

Sample HTML form:

ie_form

HTML source:

<form method="post" action="Service.svc/invoke">
    <label for="firstName">First Name</label>: <input type="text" name="firstName" value="" />
    <br /><br />
    <label for="lastName">Last Name</label>: <input type="text" name="lastName" value="" />
    <p><input type="submit" /></p>
</form>

Here’s how you read the input Stream:

public void DoWork(Stream input)
{
    StreamReader sr = new StreamReader(input);
    string s = sr.ReadToEnd();
    sr.Dispose();
    NameValueCollection qs = HttpUtility.ParseQueryString(s);
    string firstName = qs["firstName"];
    string lastName = qs["lastName"];
    // Do work here
}

I’ve attached the full sample.

Hope this helps

  • http://www.phindme.net Michael Krauklis

    Thanks Edgardo! Your post helped me to do exactly what I was looking to do, with the added benefit of having direct access to the request stream. Kudos!

  • pandu

    Thank you very much, good post helped me in implementing oAuth.

  • http://www.geeks.ltd.uk/ geeks

    Hey, that was interesting,

    Thanks for writing about it

  • Col

    Thanks, been thrashing around on this for half a day, you’ve provided a good clear example. I was going down the route of writing a WCF interceptor…..

  • http://myfreakinname.blogspot.com rufwork

    1 virtual beer. Thank you very much.

    Was trying to get an ExtJS JsonStore to send raw parameters to a WCF service. Catch-22 was that WCF doesn’t accept raw params, and JsonStore seems to like to throw POSTs only (by default) when loading data. And this breaks the deadlock. Very nice.

  • http://mjac.co.uk/ Michael Clark

    Thanks for this article, it was the most useful I found while figuring out how to generate a PDF with WCF. I took the input from the NameValueCollection and converted from JSON to a DataContract annotated object.

    private ReportSourceData getReportSourceDataFromPost(Stream reportPost)
    {
    StreamReader streamReader = new StreamReader(reportPost);
    string rawPostData = streamReader.ReadToEnd();
    streamReader.Dispose();

    NameValueCollection queryString = HttpUtility.ParseQueryString(rawPostData, Encoding.UTF8);
    string reportSourceDataJson = queryString[“reportSourceData”];
    byte[] reportJsonBytes = Encoding.UTF8.GetBytes(reportSourceDataJson);

    DataContractJsonSerializer jsonSerializer = new DataContractJsonSerializer(typeof(ReportSourceData));

    return (ReportSourceData)jsonSerializer.ReadObject(new MemoryStream(reportJsonBytes));
    }

  • Dmitriy

    Thanks for the great and clear example!