Unable to call RESTful web services methods

Question

Hello, I'm trying to dive into the RESTful web services world and have started with the following template:

[ServiceContract]
[AspNetCompatibilityRequirements(RequirementsMode = AspNetCompatibilityRequirementsMode.Allowed)]
[ServiceBehavior(InstanceContextMode = InstanceContextMode.PerCall)]
public class Test {
   // TODO: Implement the collection resource that will contain the SampleItem instances

   [WebGet(UriTemplate = ""), OperationContract]
   public List<SampleItem> GetCollection() {
     // TODO: Replace the current implementation to return a collection of SampleItem instances
     return new List<SampleItem>() {new SampleItem() {Id = 1, StringValue = "Hello"}};
   }

   [WebInvoke(UriTemplate = "", Method = "POST"), OperationContract]
   public SampleItem Create(SampleItem instance) {
     // TODO: Add the new instance of SampleItem to the collection
      throw new NotImplementedException();
   }

   [WebGet(UriTemplate = "{id}"), OperationContract]
   public SampleItem Get(string id) {
      // TODO: Return the instance of SampleItem with the given id
      throw new NotImplementedException();
   }

   [WebInvoke(UriTemplate = "{id}", Method = "PUT"), OperationContract]
   public SampleItem Update(string id, SampleItem instance) {
      return new SampleItem {
               Id = 99,
               StringValue = "Done"
             };
   }

   [WebInvoke(UriTemplate = "{id}", Method = "DELETE"), OperationContract]
   public void Delete(string id) {
      // TODO: Remove the instance of SampleItem with the given id from the collection
      throw new NotImplementedException();
   }
}

I am able to perform the GET operation but I am unable to perform PUT, POST or DELETE requests.

Can anyone explain me how to perform these operations and how to create the correct URLs?

Best regards

Alessandro

Answer 1

As far as I know, WebInvoke only supports GET and POST at this time. I use POST to perform PUT and DELETE action instead.

Answer 2

Could you please write me an example on how to write the request for this method? [WebInvoke(UriTemplate = "", Method = "POST"), OperationContract] public SampleItem Create(SampleItem instance)....

I cannot write a request for it and get the response.

Best regards

Alessandro

Answer 3

EDIT - Updated in response to your answer:

URL is "http://localhost/test/Test.svc/MethodName"
postData is the data you want to pass as a parameter.

In your case, it looks like you're trying to pass a type. Remember this is being posted in a URL. Break the values of the type into parameters.

Example: "http://localhost/test/Test.svc/Create?id=123456&stringValue=newSampleItem"

You'll need to change the Operation Contract to accept an int and a string instead of a SampleItem.

    [WebInvoke(UriTemplate = "Create?id={x}&stringValue={y}", Method = "POST"), OperationContract]
    public SampleItem Create(int id, string stringValue)
    {
       // Create and return the Sample Item. 
    }

Let me know how it goes.

Patrick.

Hi Alex, This is what I use to post to a Restful service...

// Create the request
WebRequest request; 
request = WebRequest.Create(url + postData); 
request.Method = "POST";  

byte[] byteArray = Encoding.UTF8.GetBytes(postData); 
request.ContentType = "application/x-www-form-urlencoded"; 
request.ContentLength = byteArray.Length;

// Get the request stream. 
Stream dataStream = request.GetRequestStream(); 

// Write the data to the request stream. 
dataStream.Write(byteArray, 0, byteArray.Length); 

// Close the Stream object. 
dataStream.Close();

// Process the response
Stream responseStream; 
responseStream = request.GetResponse().GetResponseStream();

StreamReader objReader = new StreamReader(responseStream); 

StringBuilder sb = new StringBuilder(); 
string sLine = ""; 
int i = 0; 

while (sLine != null) 
{
    i++;
    sLine = objReader.ReadLine();
    sb.Append(sLine);
}

responseStream.Close();


string responseXML = sb.ToString()

Good Luck,

Patrick

Answer 4

Hello Patrick, what do you mean with "url + postData". Suppose that my service url is http://localhost/test/Test.svc/

How is my post data formed supposing that my SampleItem is made like that:

public class SampleItem {
        public int Id { get; set; }
        public string StringValue { get; set; }
}

Sorry for the stupid questions.

Alessandro