I have a WebAPI server that has a Hub that replies to Subscribe requests by publishing an Dictionary<long, List<SpecialParam>> object.
The list of SpecialParam contains items of type SpecialParamA & SpecialParamB which both inherit SpecialParam.
When I try to capture the publish on the client:
hubProxy.On<Dictionary<long, List<SpecialParam>>>(hubMethod, res =>
{
DoStuff();
});
The DoStuff() method isn't called. If I change the publish return value to string, and change the proxy to receive a string value, the DoStuff() method is called. Therefore, the problem is with the deserialization of the SpecialParam Item.
I tried configuring on the server-side:
var serializer = JsonSerializer.Create();
serializer.TypeNameHandling = TypeNameHandling.All;
var hubConfig = new HubConfiguration();
hubConfig.Resolver.Register(typeof(JsonSerializer), () => serializer);
GlobalHost.DependencyResolver.Register(typeof(JsonSerializer), () => serializer);
But it didn't help.
I also tried adding to the client:
HubConnection hubConnection = new HubConnection(hubPath);
hubConnection.JsonSerializer.TypeNameHandling = Newtonsoft.Json.TypeNameHandling.Auto;
hubProxy = hubConnection.CreateHubProxy(hubName);
hubProxy.JsonSerializer.TypeNameHandling = Newtonsoft.Json.TypeNameHandling.Auto;
And it also didn't help.
In other solutions I found that people defined a new IParameterResolver, but it is only called when the server receives the input to the hub method, and not when the output is published from the hub.
Please help!
UPDATE
Here is what I caught with fidler:
{"$type":"Microsoft.AspNet.SignalR.Hubs.HubResponse, Microsoft.AspNet.SignalR.Core","I":"0"}
This is what the server replies to the client.
UPDATE 2
I'm still trying to figure out how to receive it already deserialized as Dictionary<long, List<SpecialParam>>.
I solved it by setting in the service:
public static void ConfigureApp(IAppBuilder appBuilder)
{
...
var service = (JsonSerializer)GlobalHost.DependencyResolver.GetService(typeof(Newtonsoft.Json.JsonSerializer));
service.TypeNameHandling = TypeNameHandling.All;
...
}
and removing the expected type in the client:
hubProxy.On(hubMethod, res =>
{
DoStuff();
});
I get the response in json form and I deserialize it with:
var serializer = new JsonSerializer();
serializer.TypeNameHandling = TypeNameHandling.All;
JObject jObject = resp as JObject;
var specialParams = jObject.ToObject<Dictionary<long, List<SpecialParam>>>(serializer);
I still don't know how to make my client receive it already deserialized.
Related
We have scenario where external API returns either User XML or Error XML based on whether request succeed or failed.
At the moment I'm passing User POCO to the restsharp and works fine. But if it fails, this object is NULL. And we won't know why it failed unless we parse the Error XML manually.
Is there a way to workaround this?
e.g.
var restClient = new RestClient(baseURL);
var request = new RestRequest(uri);
request.Method = Method.POST;
var response = restClient.Execute<User>(request);
On execution of above method the API can return Error xml object. How do I get Error object on fail and User on success?
This is possible, although the code is a little ugly. RestSharp allows you to specify your own XML deserializer, so we'll need to do that in order to make this work.
First, though, you need a data type that can store either an Error or a User (I made it generic so it works for more than just Users):
public class Result<T>
{
public T Data { get; set; }
public Error Error { get; set; }
}
So the idea is, now when you execute the request, you ask RestSharp for a Result<User> instead of just a User, i.e.:
var result = client.Execute<Result<User>>(request);
Now here's the magic required to deserialize as either an Error or a User. It's a custom deserializer that inherits from RestSharp's XmlDeserializer. Warning: this code is not tested at all, but it can hopefully point you in the right direction.
public class XmlResultDeserializer : XmlDeserializer
{
public override T Deserialize<T>(IRestResponse response)
{
if (!typeof(T).IsGenericType || typeof(T).GetGenericTypeDefinition() != typeof(Result<>))
return base.Deserialize<T>(response);
// Determine whether the response contains an error or normal data.
var doc = XDocument.Parse(response.Content);
var result = Activator.CreateInstance<T>();
if (doc.Root != null && doc.Root.Name == "Error")
{
// It's an error
var error = base.Deserialize<Error>(response);
var errorProperty = result.GetType().GetProperty("Error");
errorProperty.SetValue(result, error);
}
else
{
// It's just normal data
var innerType = typeof(T).GetGenericArguments()[0];
var deserializeMethod = typeof(XmlDeserializer)
.GetMethod("Deserialize", new[] { typeof(IRestResponse) })
.MakeGenericMethod(innerType);
var data = deserializeMethod.Invoke(this, new object[] { response });
var dataProperty = result.GetType().GetProperty("Data");
dataProperty.SetValue(result, data);
}
return result;
}
}
Then you would wire it all up like this:
var restClient = new RestClient(baseURL);
client.AddHandler("application/xml", new XmlResultDeserializer());
var request = new RestRequest(uri);
request.Method = Method.POST;
var result = restClient.Execute<Result<User>>(request);
if (response.Data.Data != null)
{
var user = response.Data.Data;
// Do something with the user...
}
else if (response.Data.Error != null)
{
var error = response.Data.Error;
// Handle error...
}
Here's my scenario:
I'm sending an Azure ServiceBus Queue message from Node.js using the node azure sdk like so:
var message = {
body: JSON.stringify({ foo: 'Bar' })
};
serviceBusService.sendQueueMessage('myQueue', message, function (error) {
if (!error) {
console.log('msessage sent');
}
});
I have a c# worker role that is listening to the Queue:
QueueClient Client = QueueClient.CreateFromConnectionString(connStr, QueueName);
Client.OnMessage((receivedMessage) =>
{
var body = receivedMessage.GetBody<string>();
});
When the GetBody method gets executed, i get the following error:
There was an error deserializing the object of type System.String. The input source is not correctly formatted
After some digging around, i found THIS article that helped me get a solution:
Client.OnMessage((receivedMessage) =>
{
var bodyJson = new StreamReader(receivedMessage.GetBody<Stream>(), Encoding.UTF8).ReadToEnd();
var myMessage = JsonConvert.DeserializeObject<MyMessage>(bodyJson);
});
If anyone has faced this issue and found a better solution, please let me know!
Thanks!
To anyone who found this question if they were getting this error from sending the message using Service Bus Explorer (like me).
Make sure you specify the correct message type in the drop down:
Thanks for the update, I was doing the reverse and this helped me. I thought I'd add to your solution for completeness. The DeserializeObject method needs the "MyMessage" class defining. In your original post, your JSON is:
{ foo: 'Bar' }
If we drop that into json2csharp (json2csharp.com) we now have the class required to complete your solution:
public class MyMessage
{
public string foo { get; set; }
}
Of course, the dependency is having Newtonsoft.Json package added to your Visual Studio solution:
Install-Package Newtonsoft.Json -Pre
Using the nuget package: Microsoft.Azure.ServiceBus
The following info is contained inside as as comment:
If a message is only being sent and received using this Microsoft.Azure.ServiceBus
client library, then the below extension methods are not relevant and should not be used.
If this client library will be used to receive messages that were sent using both WindowsAzure.Messaging client library and this (Microsoft.Azure.ServiceBus) library, then the Users need to add a User property Microsoft.Azure.ServiceBus.Message.UserProperties while sending the message. On receiving the message, this property can be examined to determine if the message was from WindowsAzure.Messaging client library and if so use the message.GetBody() extension method to get the actual body associated with the message.
---------------------------------------------- Scenarios to
use the GetBody Extension method: ----------------------------------------------
If message was constructed using the WindowsAzure.Messaging client library as
follows:
var message1 = new BrokeredMessage("contoso"); // Sending a plain string var
message2 = new BrokeredMessage(sampleObject); // Sending an actual customer object
var message3 = new BrokeredMessage(Encoding.UTF8.GetBytes("contoso")); // Sending
a UTF8 encoded byte array object await messageSender.SendAsync(message1); await
messageSender.SendAsync(message2); await messageSender.SendAsync(message3);
Then retrieve the original objects using this client library as follows: (By
default Microsoft.Azure.ServiceBus.InteropExtensions.DataContractBinarySerializer
will be used to deserialize and retrieve the body. If a serializer other than
that was used, pass in the serializer explicitly.)
var message1 = await messageReceiver.ReceiveAsync(); var returnedData1 = message1.GetBody();
var message2 = await messageReceiver.ReceiveAsync(); var returnedData2 = message1.GetBody();
var message3 = await messageReceiver.ReceiveAsync(); var returnedData3Bytes =
message1.GetBody(); Console.WriteLine($"Message3 String: {Encoding.UTF8.GetString(returnedData3Bytes)}");
------------------------------------------------- Scenarios to NOT use the GetBody
Extension method: ------------------------------------------------- If message
was sent using the WindowsAzure.Messaging client library as follows: var message4
= new BrokeredMessage(new MemoryStream(Encoding.UTF8.GetBytes("contoso"))); await
messageSender.SendAsync(message4); Then retrieve the original objects using this
client library as follows: var message4 = await messageReceiver.ReceiveAsync();
string returned = Encoding.UTF8.GetString(message4.Body); // Since message was
sent as Stream, no deserialization required here.
May it help you
With the latest Service Bus client libraries (.NET, JS, Java, Python), you can send message(s) using the JS library like this:
const serviceBusClient = new ServiceBusClient("<connectionstring>");
const sender = serviceBusClient.createSender("<queuename>");
await sender.sendMessages([{
body: {
title: "hello"
}
}]);
Note that .sendMessages takes a list as an input, even if you're just sending one message.
And get the body of the received message using .NET library like this:
await using var client = new ServiceBusClient("<connectionstring>");
ServiceBusReceiver receiver = client.CreateReceiver("<queuename>");
ServiceBusReceivedMessage receivedMessage = await receiver.ReceiveMessageAsync();
string body = receivedMessage.Body.ToString();
Console.WriteLine(body); //prints {"title":"hello"}
I'm migrating a web service to ASP.NET Web Api 2, and hitting trouble at almost the first hurdle.
I want to do this:
public class SomeController : ApiController
{
[Route("some\url")]
public object Get()
{
return { Message = "Hello" };
}
}
And be able to ask the service for either "application/json" or "application/xml" (or indeed any other potential format, such as Message Pack), and get a serialized response. But it seems it only works for JSON.
I've read this and seen the documentation which states clearly that the framework cannot handle serialization of anonymous types into XML (seriously) and that the solution is to not use XML (seriously).
When I attempt to call this and request XML as response type, I get
The 'ObjectContent`1' type failed to serialize the response body for content type 'application/xml; charset=utf-8'.
I'm not removing support for clients wanting to ask for XML - but I genuinely can't find a work around for this - what can I do?
Edit
I've added these:
System.Web.Http.GlobalConfiguration.Configuration.Formatters.XmlFormatter.SupportedMediaTypes.Clear();
config.Formatters.Insert(0, new System.Net.Http.Formatting.JsonMediaTypeFormatter());
config.Formatters.Insert(0, new System.Net.Http.Formatting.XmlMediaTypeFormatter());
as per Dalorzo's answer, but it made no difference.
For clarification, the service works absolutely fine when I call it using an accept header of application/json, but bombs when I call it with an accept header of application/xml.
You have 3 options:
Create a class with a proper name and return the object instead of an anonymous type.
Or if you want to return the anonymous instance, you should remove XML formatter, because anonymous types are not supported by XML Formatter
Create your own formatter inheriting from MediaTypeFormatter or BufferedMediaTypeFormatter
You can do it by following code :
public HttpResponseMessage GetTestData()
{
var testdata = (from u in context.TestRepository.Get().ToList()
select
new Message
{
msgText = u.msgText
});
return ActionContext.Request.CreateResponse(HttpStatusCode.OK, testdata);
}
// This Code Is Used To Change Contents In Api
public HttpResponseMessage GetAllcarDetails( string formate)
{
CarModel ST = new CarModel();
CarModel ST1 = new CarModel();
List<CarModel> li = new List<CarModel>();
ST.CarName = "Maruti Waganor";
ST.CarPrice = 400000;
ST.CarModeles = "VXI";
ST.CarColor = "Brown";
ST1.CarName = "Maruti Swift";
ST1.CarPrice = 500000;
ST1.CarModeles = "VXI";
ST1.CarColor = "RED";
li.Add(ST);
li.Add(ST1);
// return li;
this.Request.Headers.Accept.Add(
new MediaTypeWithQualityHeaderValue("application/xml"));
//For Json Use "application/json"
IContentNegotiator negotiator =
this.Configuration.Services.GetContentNegotiator();
ContentNegotiationResult result = negotiator.Negotiate(
typeof(List<CarModel>), this.Request, this.Configuration.Formatters);
if (result == null) {
var response = new HttpResponseMessage(HttpStatusCode.NotAcceptable);
throw new HttpResponseException(response);
}
return new HttpResponseMessage() {
Content = new ObjectContent<List<CarModel>>(
li, // What we are serializing
result.Formatter, // The media formatter
result.MediaType.MediaType // The MIME type
)
};
}
Please browse your API route on Chrome. Chrome, by default shows output in XML format. If that doesn't happen, it means that your service is preventing XML format using media formatting.
And in that case, you should search your WebApiConfig. If nothing is present there, add this file to your project
using System.Net.Http.Formatting;
using System.Collections.Generic;
using System.Net.Http;
using System;
using System.Linq;
using System.Net.Http.Headers;
namespace ExampleApp.Infrastructure
{
public class CustomNegotiator : DefaultContentNegotiator
{
public override ContentNegotiationResult Negotiate(Type type, HttpRequestMessage request, IEnumerable<MediaTypeFormatter> formatters)
{
if(request.Headers.UserAgent.Where(x=>x.Product!=null&& x.Product.Name.ToLower().Equals("chrome")).Count() > 0)
{
return new ContentNegotiationResult(new JsonMediaTypeFormatter(), new MediaTypeHeaderValue("application/xml"));
}
else
{
return base.Negotiate(type, request, formatters);
}
}
}
}
and, in WebApiConfig.cs, add:
config.Services.Replace(typeof(IContentNegotiator), new CustomNegotiator());
in asp web api i have this controller that respond to ajax request and send back json data:
public IEnumerable<PersonaleDTO> GetPersonale()
{
var n = (from p in db.Personale
select new PersonaleDTO { Id = p.Id, Nome = p.Nome, Cognome = p.Cognome Cellulare = p.Cellulare, Email = p.Email, Attivo = (bool)p.Attivo }).ToList();
return n;
}
This method return seven object and it's correct.
Now when i receive back the data in the json format i see that i receive also and $id member along with the id, Nome, Cognome...
What is the $id variable? How can remove this from the json response?
Try this code in WebApiConfig
var json = config.Formatters.JsonFormatter;
json.SerializerSettings.PreserveReferencesHandling = Newtonsoft.Json.PreserveReferencesHandling.None;
Edit : If for some reason you're using a custom ContractResolver then as per this post
The custom ContractResolver setting overrides the PreserveReferencesHandling setting.
In your implementation of DefaultContractResolver/IContractResolver, add this;
public override JsonContract ResolveContract(Type type) {
var contract = base.ResolveContract(type);
contract.IsReference = false;
return contract;
}
This behaves similarly to the PreserveReferencesHandling.None setting without a custom ContractResolver.
I'm trying to use custom media type formatters to implement (part of the) versioning for a Web API service. This works fine with standard Web API controller methods. The service also uses SignalR to notify connected clients of certain changes. Below the relevant code of the Hub:
public void BroadCastAnalyzerGroupRemoved(string groupId)
{
hubContext.Clients.All.AnalyzerGroupRemoved(
new AnalyzerGroupRemovedMessage()
{
AnalyzerGroupId = groupId
});
}
Without use of custom media type formatters this worked fine. When removing all formatters from the HttpConfiguration and adding only my custom ones like below, the code above throws the following exception:
Microsoft.CSharp.RuntimeBinder.RuntimeBinderException occurred
_HResult=-2146233088
_message='Microsoft.AspNet.SignalR.Hubs.ClientProxy' does not contain a definition for 'AnalyzerGroupRemoved'
HResult=-2146233088
IsTransient=false
Message='Microsoft.AspNet.SignalR.Hubs.ClientProxy' does not contain a definition for 'AnalyzerGroupRemoved'
Source=Microsoft.CSharp
StackTrace:
at Microsoft.CSharp.RuntimeBinder.RuntimeBinderController.SubmitError(CError pError)
InnerException:
The code used to configure formatters looks like this:
config.Formatters.Clear();
var formatters = container.Resolve<IEnumerable<MediaTypeFormatter>>();
formatters.ForEach(f => config.Formatters.Add(f));
Where the container object is an Autofac container that contains all the custom media type formatters.
I've verified that the media type formatter for the AnalyzerGroupRemovedMessage is created and added to the container.
Do I need to add some code to the registration at the client side?
The code to register currently looks like this:
[Test]
public async Task TestRemovingAGroupNotifiesClients()
{
var hubConnection = new HubConnection(uriBuilder.SignalRHubUri, useDefaultUrl: false);
hubConnection.Error += ex => { throw new Exception("Exception from hubConnection",ex); };
hubConnection.TraceLevel = TraceLevels.All;
hubConnection.TraceWriter = new DebugTextWriter();
var proxy = hubConnection.CreateHubProxy("AnalyzerGroupsHub");
const string groupId = "138";
var eventWasRecieved = new AutoResetEvent(false);
string groupIdRecieved = null;
proxy.On<AnalyzerGroupRemovedMessage>("AnalyzerGroupRemoved", message =>
{
groupIdRecieved = message.AnalyzerGroupId;
eventWasRecieved.Set();
});
hubConnection.Start().Wait();
var removeResult = await RequestHelper.InvokeWebRequest(
uriBuilder.AnalyzerGroupUri(groupId),
HttpMethod.Delete);
Assert.AreEqual(HttpStatusCode.NoContent, removeResult.StatusCode);
var waitResult = eventWasRecieved.WaitOne(TimeSpan.FromSeconds(1));
Assert.IsTrue(waitResult);
Assert.AreEqual(groupId, groupIdRecieved);
}
I was unable to find any information on the internet regarding this topic, any pointers to resources would also be very much appreciated.