Communication between Rails and WCF
I am currently working on a WCF application that consumes a Rails REST Service. The problem is when I do a update or remove request, Rails does not return XML, only the following header:
HTTP/1.1 200 OK
Date: Wed, 13 Jan 2010 13:56:25 GMT
Server: Apache/2.2.14 (Debian)
X-Powered-By: Phusion Passenger (mod_rails/mod_rack) 2.2.7
X-Runtime: 20
Cache-Control: private, max-age=0, must-revalidate
Set-Cookie: _Shop-R+Server_session=BAh7BzoPc2Vzc2lvbl9pZCIlODY0NmZlZjQyZTg1OTcyNTE0ZTRlN2NkNTcyZDVmYTEiCmZsYXNoSUM6J0FjdGlvbkNvbnRyb2xsZXI6OkZsYXNoOjpGbGFzaEhhc2h7BjoLbm90aWNlIidDdXN0b21lciB3YXMgc3VjY2Vzc2Z1bGx5IHVwZGF0ZWQuBjoKQHVzZWR7BjsHRg%3D%3D--88d0f739a开发者_如何学C64ea3a92e3a034d73365393dcfeee1e; path=/; HttpOnly
Content-Length: 1
Status: 200
Content-Type: application/xml; charset=utf-8
This is to be expected and correct as far as I know. However when calling the following service request from WCF we get a ProtocolException (InnerException: XMLException Unexpected end of file).
[ServiceContract]
[XmlSerializerFormat]
public interface ICustomerService
{
[OperationContract]
[WebGet(
BodyStyle = WebMessageBodyStyle.Bare,
ResponseFormat = WebMessageFormat.Xml,
UriTemplate = "customers/{id}.xml")]
Customer GetCustomer(string id);
[OperationContract]
[WebInvoke(
BodyStyle = WebMessageBodyStyle.Bare,
UriTemplate = "customers/{id}.xml",
Method = "PUT")]
void UpdateCustomer(string id, Customer newCustomer);
[OperationContract]
[WebInvoke(
BodyStyle = WebMessageBodyStyle.Bare,
ResponseFormat = WebMessageFormat.Xml,
UriTemplate = "customers.xml",
Method = "POST")]
Customer CreateCustomer(Customer newCustomer);
[OperationContract]
[WebInvoke(
BodyStyle = WebMessageBodyStyle.Bare,
UriTemplate = "customers/{id}.xml",
Method = "DELETE")]
void DeleteCustomer(string id);
}
The GetCustomer and CreateCustomer methods work without a problem, UpdateCustomer and DestroyCustomer throw the exception. We suspect this is because XML is expected as a response.
Does anybody have any experience with Rails and WCF and knows a solution/workaround for this problem?
For completeness here are the exception details:
ProtocolException {"There is a problem with the XML that was received from the network. See inner exception for more details."}
XMLException (InnerException) {"Unexpected end of file."} StackTrace:
at System.Xml.EncodingStreamWrapper.ProcessBuffer(Byte[] buffer, Int32 offset, Int32 count, Encoding encoding)
at System.Xml.XmlUTF8TextReader.SetInput(Byte[] buffer, Int32 offset, Int32 count, Encoding encoding, XmlDictionaryReaderQuotas quotas, OnXmlDictionaryReaderClose onClose)
at System.Xml.XmlDictionaryReader.CreateTextReader(Byte[] buffer, Int32 offset, Int32 count, Encoding encoding, XmlDictionaryReaderQuotas quotas, OnXmlDictionaryReaderClose onClose)
at System.ServiceModel.Channels.TextMessageEncoderFactory.TextMessageEncoder.UTF8BufferedMessageData.TakeXmlReader()
at System.ServiceModel.Channels.BufferedMessageData.GetMessageReader()
at System.ServiceModel.Channels.BufferedMessage..ctor(IBufferedMessageData messageData, RecycledMessageState recycledMessageState, Boolean[] understoodHeaders)
at System.ServiceModel.Channels.TextMessageEncoderFactory.TextMessageEncoder.ReadMessage(ArraySegment`1 buffer, BufferManager bufferManager, String contentType)
at System.ServiceModel.Channels.WebMessageEncoderFactory.WebMessageEncoder.ReadMessage(ArraySegment`1 buffer, BufferManager bufferManager, String contentType)
at System.ServiceModel.Channels.HttpInput.DecodeBufferedMessage(ArraySegment`1 buffer, Stream inputStream)
Content-Length: 1
Content-Type: application/xml; charset=utf-8
Is not a valid XML response.
I've already found it, thanks to "Darin Dimitrov" and "Nate Bross". They were right that WCF expects XML when you set the content-type to application/xml. I've changed the content-type to text/plain (in rails) and it works.
Change the following in your rails formatting:
format.xml { head :ok }
to
format.xml { head :ok, :content_type => 'text/plain' }
Go download the REST Starter Kit Preview 2 and take a look at the Microsoft.Http namespace. Using this library doing the POST to the Rails interface is as easy as this:
var client = new HttpClient("http://railsinterface.com");
var content = HttpContent.CreateXmlSerializable<Customer>(customer);
var response = client.Post("customers.xml",content);
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