Serialize public properties using JSON.NET - c#

I'm using JSON.NET implementation to serialize/deserialize .NET objects to JS and vice versa, all works fine until running GetWCFData() in the following:
using Newtonsoft.Json;
using Newtonsoft.Json.Converters;
public class WebLookup
{
WCFService.WCFServiceClient svc;
IsoDateTimeConverter DateConverter = new IsoDateTimeConverter();
List<WCFContract.Language> Languages { get; set; }
List<WCFContract.Group> Groups { get; set; }
List<WCFContract.User> Users { get; set; }
public WebLookup()
{
DateConverter.DateTimeFormat = "dd/MM/yyyy";
DateConverter.DateTimeStyles = System.Globalization.DateTimeStyles.AssumeLocal;
}
public string GetWCFData()
{
svc = new WCFService.WCFServiceClient();
WebLookup weblookup = new WebLookup();
weblookup.Languages = svc.GetWCFLanguages().ToList();
weblookup.Groups = svc.GetWCFGroups().ToList();
weblookup.Users = svc.GetWCFUsers().ToList();
return JsonConvert.SerializeObject(weblookup, DateConverter);
}
}
Members Languages, Groups, and Users get populated successfully when calling the WCF service but
JsonConvert.SerializeObject(lookup, DateConverter) always returns an empty JSON string to the client (web browser), this is strange as it usually works fine for me in other areas, the only difference is that here I have the populated WebLookup members declared as public properties in the class itself.

Languages, Groups and Users properties need to be declared as Public members in order to be Serialised by either JSON.NET or the built-in JavaScriptSerializer, this is not the case in your code.

Related

Strange JSON Deserialization c#

I'm having troubles with some Deserialization because I'm not receiving an object like I'm used to but an array. Lets to the code, how I've being doing it:
JSON received:
[{"gcm_regID":"fsdf2156fw62f1wfwe512g"}]
Deserialization
var result = JsonConvert.DeserializeObject<Gcm>(response);
Handlers Tried:
public class Gcm
{
public List<Gcm_reg> gcm_regID { get; set; }
}
public class Gcm_reg
{
public string gcm_regID { get; set; }
}
I've tried just the Gcm_reg as well and nothing seems to work. How can I deserialize this? By the way, I'm using the newsoft JSON.
Best regards,
IEnumerable<Gcm_reg> result = JsonConvert.DeserializeObject<IEnumerable<Gcm_reg>>(response);
You can deserialize the object as an array or IEnumerable
Object should be like
public class Gcm
{
public string gcm_regID { get; set; }
}
So Try it
var result = JsonConvert.DeserializeObject<IEnumerable<Gcm>>(response);
You can directly generate classes from Json by using link
To create same type of object
var outputList = new List<Gcm>();
//loop through this part based on number of input
var itemToAdd = new Gcm();
itemToAdd .regID = 'something';
outputList.Add(itemToAdd );
and send outputList to server.

Getting DataContractSerializer error

I'm not sure to what i'm doing wrong here but its now been a couple of days of me trying to solve this out but still no luck.
I have a model like this:
public class Event
{
public int Id {get;set;}
public string EventName {get;set;}
public DateTime StartTime{get;set;}
public DateTime FinishTime {get;set;}
}
Then i have a web Api method like this :
[HttpGet]
public IQueryable GetTimes()
{
var times = context.Events.where(x => x.EventName == "even name").Select(x => x new{
x.Id,
x.EventName,
StartTime = x.StartTime.ToShortTimeString(), // just getting time only
FinishTime = x.FinishTime.ToShortTimeString() // just getting time only
});
}
When I run my project I get the following error:
ArrayOf_x003C__x003E_f__AnonymousType0Ofintstringstringstringstringdoubledoublestring:http://schemas.datacontract.org/2004/07/'
is not expected. Consider using a DataContractResolver if you are
using DataContractSerializer or add any types not known statically to
the list of known types - for example, by using the KnownTypeAttribute
attribute or by adding them to the list of known types passed to the
serializer
I have never seen this error before and I'm not so sure on how to tackle this one.
I have also realized that when I run a test for instance if I do the following in that method:
x.Id,
x.EventName,
StartTime = "12.30", // this works fine and no error is thrown.
FinishTime = "16.30"
//also the following works fine:
x.Id,
x.EventName,
x.StartTime,
x.FinishTime, // this works fine obviously i only need the time only
How is this caused and how can I fix this?
The DataContractJsonSerializer cannot serialize anonymous types. Are you allowed to use another built-in serializer? In that case you can use the standard JSON serializer by setting your HttpConfiguration as follows:
httpConfiguration.Formatters.Clear();
httpConfiguration.Formatters.Add(new JsonMediaTypeFormatter());
You could also write a custom attribute to disable the DataContractJsonSerializer for a particular controller only:
public class UseDefaultJsonSerializerAttribute : Attribute, IControllerConfiguration
{
public void Initialize(
HttpControllerSettings controllerSettings,
HttpControllerDescriptor controllerDescriptor)
{
controllerSettings.Formatters.Clear();
controllerSettings.Formatters.Add(new JsonMediaTypeFormatter());
}
}
The problem is occurring because the DataContractSerializer on the client side ,used for deserializing the result, is expecting an array of a specific type and the server is handing out an array of an anonymous type. You need to use the same type on the server and client or 2 types that use the same Data Contract (which is how the generated proxy classes the VS creates work).
Try creating a Data Transfer Object (DTO) class to use on both client and server.
[DataContact]
public class EventDTO {
[DataMember]
public int Id { get; set; }
[DataMember]
public string EventName { get; set; }
[DataMember]
public TimeSpan StartTime { get; set; }
[DataMember]
public TimeSpan EndTime {get;set;}
}
Nowe your get method can look like
[HttpGet]
public IQueryable<EventDTO> GetTimes()
{
return context.Events.where(x => x.EventName == "even name")
.Select(x => x new EventDTO
{
Id = x.Id,
EventName = x.EventName,
StartTime = x.StartTime.TimeOfDay,
FinishTime = x.FinishTime.TimeOfDay
});
}
Make sure you use the same type for your Deserializer on the client

ServiceStack C# strongly typed client DTO

Here: Recommended ServiceStack API Structure and here: https://github.com/ServiceStack/ServiceStack/wiki/Physical-project-structure are recommendations for how to structure your projects for C# clients to reuse DTOs.
Apparently this is done by including a dll of the DTO assembly. I have searched the web for one example, just Hello World that uses a separate assembly DTO for a C# client in ServiceStack. Perhaps I should be able to break this out myself but so far it has not proven that easy.
Almost all client descriptions are for generic and non-typed JSON or other non-DTO based clients. No one appears interested in typed C# clients like I am (even the ServiceStack documentation I have found). So I thought this would be a good question even if I figure it out myself in the end.
To be clear, I have built and run the Hello World example server. I have also used a browser to attach to the server and interact with it. I have also created a client empty project that can call
JsonServiceClient client = new JsonServiceClient(myURL);
Then I tried to copy over my DTO definition without the assembly DLL as I don't have one. I get ResponseStatus is undefined.
Clearly there is something missing (it appears to be defined in ServiceStack.Interfaces.dll) and if I could create a dll of the DTO I think it would resolve all references.
Can anyone give insight into how to create the DTO assembly for the simple Hello World?
Edited to add code:
using ServiceStack.ServiceClient.Web;
namespace TestServiceStack
{
class HelloClient
{ public class HelloResponse
{
public string Result { get; set; }
public ResponseStatus ResponseStatus { get; set; } //Where Exceptions get auto-serialized
}
//Request DTO
public class Hello
{
public string Name { get; set; }
}
HelloResponse response = client.Get(new Hello { Name = "World!" });
}
}
Where the ResponceStatus is undefined.
I was able to find the missing symbol ResponseStatus by adding:
using ServiceStack.ServiceInterface.ServiceModel;
Here is the full code that built. Keep in mind that I found out something else in the process. Once this built it then failed because I was using a DTO from a .NET 4.0 environment in a .NET 3.5 environment. But that is an unrelated issue. Also note that this test code does nothing with the response, it is just an example to get the build working.
using ServiceStack.ServiceClient;
using ServiceStack.ServiceInterface;
using ServiceStack.Text;
using ServiceStack.Service;
using ServiceStack.ServiceHost;
using ServiceStack.WebHost;
using ServiceStack;
using ServiceStack.ServiceClient.Web;
using RestTestRoot; // This is the name of my DTO assembly. You will need to insert your own here.
using ServiceStack.ServiceInterface.ServiceModel;
namespace WebApplicationRoot
{
class HelloClient
{
JsonServiceClient hello_client;
//Request DTO
public class Hello
{
public string Name { get; set; }
}
//Response DTO
public class HelloResponse
{
public string Result { get; set; }
public ResponseStatus ResponseStatus { get; set; } //Where Exceptions get auto-serialized
}
//Can be called via any endpoint or format, see: http://mono.servicestack.net/ServiceStack.Hello/
public class HelloService : Service
{
public object Any(Hello request)
{
return new HelloResponse { Result = "Hello, " + request.Name };
}
}
//REST Resource DTO
[Route("/todos")]
[Route("/todos/{Ids}")]
public class Todos : IReturn<List<Todo>>
{
public long[] Ids { get; set; }
public Todos(params long[] ids)
{
this.Ids = ids;
}
}
[Route("/todos", "POST")]
[Route("/todos/{Id}", "PUT")]
public class Todo : IReturn<Todo>
{
public long Id { get; set; }
public string Content { get; set; }
public int Order { get; set; }
public bool Done { get; set; }
}
public HelloClient(){
// ServiceStack gateway = new ServiceStack.ClientGateway(
// location.protocol + "//" + location.host + '/ServiceStack.Examples.Host.Web/ServiceStack/');
hello_client = new JsonServiceClient("http://tradetree2.dnsapi.info:8080/");
hello_client.Get<HelloResponse>("/hello/MyTestWorld!");
}
}
}

Serializer ignores properties that use another serialized property

I am working on an endpoint in asp.net that serializes and returns some data, using the default serializer.
The consuming applications are transitioning between changing names for properties (in other words, some existing applications are using names like ...Vat; while newer ones are using ...Tax. I therefore need to keep both names in the response for the moment, until these changes are complete.
The return type is IList.
public class Product
{
...
public decimal PriceIncVat { get; set; }
public decimal PriceIncTax { get { return PriceIncVat; } }
public int TaxCode { get; set; }
...
}
However, when I examine the response in fiddler, only the PriceIncVat property exists in the json list of products.
I can't think of any reason why the above wouldn't work. I added TaxCode at the same time as PriceIncTax, and it is returned, so I know the code of the endpoint is up to date.
And on the client side of a newer client project we have:
public class ProductDto
{
...
public decimal PriceIncTax { get; set; }
public string TaxCode { get; set; }
...
}
Very confused here.
The serializer assumes you will need to deserialize the data some time. Hence by default only properties with a getter and a setter are considered.
When using the DataContractJsonSerializer, it's possible to turn on serialization of read-only properties using the SerializeReadOnlyTypes property (despite its rather misleading name).
Side note: Check-out the Json.NET serializer, which gives more options and better control over the (de)serialization process.

ServiceStack support for conditionally omitting fields from a REST response on a per-call basis

<TL;DR>
At a minimum, I'm looking for a way to conditionally exclude certain properties on the resource from being included in the response on a per-call basis (See fields below).
Ideally, I'd like to implement a REST service with ServiceStack that supports all the major points below.
UPDATE
While I really like ServiceStack's approach in general and would prefer to use it if possible, if it isn't particularly well suited towards these ideas I'd rather not bend over backwards bastardizing it to make it work. If that's the case, can anyone point to another c# framework that might be more appropriate? I'm actively exploring other options myself, of course.
</TD;DR>
In this talk entitled Designing REST + JSON APIs, the presenter describes his strategy for Resource References (via href property on resources) in JSON. In addition to this, he describes two query parameters (fields and expand) for controlling what data is included the response of a call to a REST service. I've been trying without success to dig into the ServiceStack framework to achieve support for fields in particular but have thus far been unsuccessful. Is this currently possible in ServiceStack? Ideally the solution would be format agnostic and would therefore work across all of ServiceStack's supported output formats. I would imagine expand would follow the same strategy.
I'll describe these features here but I think the talk at the link does a better job of explaining them.
Lets say we have an Profiles resource with the following properties: givenName, surname, gender, and favColor. The Profiles resource also includes a list of social networks the user belongs to in the socialNetworks property.
href - (42:22 in video) Every resource includes a full link to it on the REST service. A call to GET /profiles/123 would return
{
"href":"https://host/profiles/123",
"givenName":"Bob",
"surname":"Smith",
"gender":"male",
"favColor":"red",
"socialNetworks": {
"href":"https://host/socialNetworkMemberships?profileId=123"
}
}
Notice that the socialNetworks property returns an object with just the href value populated. This keeps the response short and focused while also giving the end user enough information to make further requests if desired. The href property, used across the board in this manor, makes it easy (conceptually anyway) to reuse resource data structures as children of other resources.
fields - (55:44 in video) Query string parameter that instructs the server to only include the specified properties of the desired resource in the REST response.
A normal response from GET /profiles/123 would include all the properties of the resource as seen above. When the fields query param is included in the request, only the fields specified are returned. 'GET /propfiles/123?fields=surname,favColor' would return
{
"href":"https://host/profiles/123",
"surname":"Smith",
"favColor":"red"
}
expand - (45:53 in video) Query string parameter that instructs the server to flesh out the specified child resources in the result. Using our example, if you were to call GET /profiles/123?expand=socialNetworks you might receive something like
{
"href":"https://host/profiles/123",
"givenName":"Bob",
"surname":"Smith",
"gender":"male",
"favColor":"red",
"socialNetworks": {
"href":"https://host/socialNetworkMemberships?profileId=123",
"items": [
{
"href":"https://host/socialNetworkMemberships/abcde",
"siteName":"Facebook",
"profileUrl":"http://www.facebook.com/..."
},
...
]
}
}
So...in my opinion ServiceStack's best feature is that it makes sending, receiving and handling POCOs over HTTP super easy. How you set up the POCOs and what you do in between (within the 'Service') is up to you. Does SS have opinions? Yes. Do you have to agree with them? No. (But you probably should :))
I think expanding on something like below would get you close to how you want to handle your api. Probably not the best example of ServiceStack but the ServiceStack code/requirements are barely noticeable and don't get in your way (AppHost configure not shown). You could probably do something similar in other .NET Frameworks (MVC/Web API/etc) but, in my opinion, won't look as much like straight C#/.NET code as with ServiceStack.
Request classes
[Route("/Profiles/{Id}")]
public class Profiles
{
public int? Id { get; set; }
}
[Route("/SocialNetworks/{Id}")]
public class SocialNetworks
{
public int? Id { get; set; }
}
Base Response class
public class BaseResponse
{
protected virtual string hrefPath
{
get { return ""; }
}
public string Id { get; set; }
public string href { get { return hrefPath + Id; } }
}
Classes from example
public class Profile : BaseResponse
{
protected override string hrefPath { get { return "https://host/profiles/"; } }
public string GivenName { get; set; }
public string SurName { get; set; }
public string Gender { get; set; }
public string FavColor { get; set; }
public List<BaseResponse> SocialNetworks { get; set; }
}
public class SocialNetwork: BaseResponse
{
protected override string hrefPath { get { return "https://host/socialNetworkMemberships?profileId="; }}
public string SiteName { get; set; }
public string ProfileUrl { get; set; }
}
Services
public class ProfileService : Service
{
public object Get(Profiles request)
{
var testProfile = new Profile { Id= "123", GivenName = "Bob", SurName = "Smith", Gender = "Male", FavColor = "Red",
SocialNetworks = new List<BaseResponse>
{
new SocialNetwork { Id = "abcde", SiteName = "Facebook", ProfileUrl = "http://www.facebook.com/"}
}
};
if (!String.IsNullOrEmpty(this.Request.QueryString.Get("fields")) || !String.IsNullOrEmpty(this.Request.QueryString.Get("expand")))
return ServiceHelper.BuildResponseObject<Profile>(testProfile, this.Request.QueryString);
return testProfile;
}
}
public class SocialNetworkService : Service
{
public object Get(SocialNetworks request)
{
var testSocialNetwork = new SocialNetwork
{
Id = "abcde",
SiteName = "Facebook",
ProfileUrl = "http://www.facebook.com/"
};
if (!String.IsNullOrEmpty(this.Request.QueryString.Get("fields")) || !String.IsNullOrEmpty(this.Request.QueryString.Get("expand")))
return ServiceHelper.BuildResponseObject<SocialNetwork>(testSocialNetwork, this.Request.QueryString);
return testSocialNetwork;
}
}
Reflection Helper Class
public static class ServiceHelper
{
public static object BuildResponseObject<T>(T typedObject, NameValueCollection queryString) where T: BaseResponse
{
var newObject = new ExpandoObject() as IDictionary<string, object>;
newObject.Add("href", typedObject.href);
if (!String.IsNullOrEmpty(queryString.Get("fields")))
{
foreach (var propertyName in queryString.Get("fields").Split(',').ToList())
{
//could check for 'socialNetwork' and exclude if you wanted
newObject.Add(propertyName, typedObject.GetType().GetProperty(propertyName, BindingFlags.IgnoreCase | BindingFlags.Public | BindingFlags.Instance).GetValue(typedObject, null));
}
}
if (!String.IsNullOrEmpty(queryString.Get("expand")))
{
foreach (var propertyName in queryString.Get("expand").Split(',').ToList())
{
newObject.Add(propertyName, typedObject.GetType().GetProperty(propertyName, BindingFlags.IgnoreCase | BindingFlags.Public | BindingFlags.Instance).GetValue(typedObject, null));
}
}
return newObject;
}
}
Usually you can control the serialization of your DTOs by setting the DataMember attributes. With those attributes you can control if the property should have defaults or not.
Meaning if you simply do not define the property of the object you want to return, it should not be serialized and therefore will not be shown in the resulting Json.
ServiceStack internally uses the standard DataContract...Serializer, so this should be supported
Otherwise you could also make use of dynamic objects and simply compose your object at runtime, serialize it and send it back.
Here is a very very basic example:
var seri = JsonSerializer.Create(new JsonSerializerSettings() { });
using (var textWriter = new StringWriter())
{
var writer = new JsonTextWriter(textWriter);
dynamic item = new { Id = id };
seri.Serialize(writer, item);
return textWriter.ToString();
}

Categories

Resources