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I am working with ASP.NET MVC 5 Web Api. I want consult all my users.
I wrote api/users and I receive this:
"The 'ObjectContent`1' type failed to serialize the response body for content type 'application/json; charset=utf-8'"
In WebApiConfig, already I added these lines:
HttpConfiguration config = new HttpConfiguration();
config.Formatters.XmlFormatter.SupportedMediaTypes.Remove(appXmlType);
config.Formatters.JsonFormatter.SerializerSettings.ReferenceLoopHandling = Newtonsoft.Json.ReferenceLoopHandling.Ignore;
But it still doesn't work.
My function for return data is this:
public IEnumerable<User> GetAll()
{
using (Database db = new Database())
{
return db.Users.ToList();
}
}
If you are working with EF, besides adding the code below on Global.asax
GlobalConfiguration.Configuration.Formatters.JsonFormatter.SerializerSettings
.ReferenceLoopHandling = Newtonsoft.Json.ReferenceLoopHandling.Ignore;
GlobalConfiguration.Configuration.Formatters
.Remove(GlobalConfiguration.Configuration.Formatters.XmlFormatter);
Dont`t forget to import
using System.Data.Entity;
Then you can return your own EF Models
Simple as that!
When it comes to returning data back to the consumer from Web Api (or any other web service for that matter), I highly recommend not passing back entities that come from a database. It is much more reliable and maintainable to use Models in which you have control of what the data looks like and not the database. That way you don't have to mess around with the formatters so much in the WebApiConfig. You can just create a UserModel that has child Models as properties and get rid of the reference loops in the return objects. That makes the serializer much happier.
Also, it isn't necessary to remove formatters or supported media types typically if you are just specifying the "Accepts" header in the request. Playing around with that stuff can sometimes make things more confusing.
Example:
public class UserModel {
public string Name {get;set;}
public string Age {get;set;}
// Other properties here that do not reference another UserModel class.
}
Given right answer is one way to go, however it is an overkill when you can fix it by one config settings.
Better to use it in the dbcontext constructor
public DbContext() // dbcontext constructor
: base("name=ConnectionStringNameFromWebConfig")
{
this.Configuration.LazyLoadingEnabled = false;
this.Configuration.ProxyCreationEnabled = false;
}
Asp.Net Web API Error: The 'ObjectContent`1' type failed to serialize the response body for content type 'application/xml; charset=utf-8'
Add this code to global.asax below on Application_Start:
Update from .Ignore to .Serialize . It must work.
GlobalConfiguration.Configuration.Formatters.JsonFormatter.SerializerSettings.ReferenceLoopHandling = Newtonsoft.Json.ReferenceLoopHandling.Serialize;
GlobalConfiguration.Configuration.Formatters.Remove(GlobalConfiguration.Configuration.Formatters.XmlFormatter);
public class UserController : ApiController
{
Database db = new Database();
// construction
public UserController()
{
// Add the following code
// problem will be solved
db.Configuration.ProxyCreationEnabled = false;
}
public IEnumerable<User> GetAll()
{
return db.Users.ToList();
}
}
I resolved it using this code to WebApiConfig.cs file
var json = config.Formatters.JsonFormatter;
json.SerializerSettings.PreserveReferencesHandling = Newtonsoft.Json.PreserveReferencesHandling.Objects;
config.Formatters.Remove(config.Formatters.XmlFormatter);
I don't like this code:
foreach(var user in db.Users)
As an alternative, one might do something like this, which worked for me:
var listOfUsers = db.Users.Select(r => new UserModel
{
userModel.FirstName = r.FirstName;
userModel.LastName = r.LastName;
});
return listOfUsers.ToList();
However, I ended up using Lucas Roselli's solution.
Update: Simplified by returning an anonymous object:
var listOfUsers = db.Users.Select(r => new
{
FirstName = r.FirstName;
LastName = r.LastName;
});
return listOfUsers.ToList();
Adding this in your Application_Start() method of Global.asax file should solve the problem
protected void Application_Start()
{
GlobalConfiguration.Configuration.Formatters.JsonFormatter.SerializerSettings
.ReferenceLoopHandling = Newtonsoft.Json.ReferenceLoopHandling.Ignore;
GlobalConfiguration.Configuration.Formatters
.Remove(GlobalConfiguration.Configuration.Formatters.XmlFormatter);
// ...
}
METHOD 2: [Not recommended]
If you are working with EntityFramework, you can disable proxy in your DbContext class constructor. NOTE: this code wll be removed if you update the model
public class MyDbContext : DbContext
{
public MyDbContext()
{
this.Configuration.ProxyCreationEnabled = false;
}
}
There's also this scenario that generate same error:
In case of the return being a List<dynamic> to web api method
Example:
public HttpResponseMessage Get()
{
var item = new List<dynamic> { new TestClass { Name = "Ale", Age = 30 } };
return Request.CreateResponse(HttpStatusCode.OK, item);
}
public class TestClass
{
public string Name { get; set; }
public int Age { get; set; }
}
So, for this scenario use the [KnownTypeAttribute] in the return class (all of them) like this:
[KnownTypeAttribute(typeof(TestClass))]
public class TestClass
{
public string Name { get; set; }
public int Age { get; set; }
}
This works for me!
My personal favorite: Just add the code below to App_Start/WebApiConfig.cs. This will return json instead of XML by default and also prevent the error you had. No need to edit Global.asax to remove XmlFormatter etc.
The 'ObjectContent`1' type failed to serialize the response body for content type 'application/xml; charset=utf-8
config.Formatters.JsonFormatter.SupportedMediaTypes.Add(new MediaTypeHeaderValue("text/html"));
Just put following lines in global.asax:
GlobalConfiguration.Configuration.Formatters.JsonFormatter.SerializerSettings.ReferenceLoopHandling = Newtonsoft.Json.ReferenceLoopHandling.Ignore;
GlobalConfiguration.Configuration.Formatters.Remove(GlobalConfiguration.Configuration.Formatters.XmlFormatter);
Import
using System.Data.Entity;
Use AutoMapper...
public IEnumerable<User> GetAll()
{
using (Database db = new Database())
{
var users = AutoMapper.Mapper.DynamicMap<List<User>>(db.Users);
return users;
}
}
Use the following namespace:
using System.Web.OData;
Instead of :
using System.Web.Http.OData;
It worked for me
Add the below line
this.Configuration.ProxyCreationEnabled = false;
Two way to use ProxyCreationEnabled as false.
Add it inside of DBContext Constructor
public ProductEntities() : base("name=ProductEntities")
{
this.Configuration.ProxyCreationEnabled = false;
}
OR
Add the line inside of Get method
public IEnumerable<Brand_Details> Get()
{
using (ProductEntities obj = new ProductEntities())
{
this.Configuration.ProxyCreationEnabled = false;
return obj.Brand_Details.ToList();
}
}
Use [Serializable] for class:
Example:
[Serializable]
public class UserModel {
public string Name {get;set;}
public string Age {get;set;}
}
It worked for me!
Solution that worked for me:
Use [DataContract] for class and [DataMember] attributes for each property to serialize. This is enough to get Json result (for ex. from fiddler).
To get xml serialization write in Global.asax this code:
var xml = GlobalConfiguration.Configuration.Formatters.XmlFormatter;
xml.UseXmlSerializer = true;
Read this article, it helped me to understand serialization:
https://www.asp.net/web-api/overview/formats-and-model-binding/json-and-xml-serialization
To add to jensendp's answer:
I would pass the entity to a user created model and use the values from that entity to set the values in your newly created model. For example:
public class UserInformation {
public string Name { get; set; }
public int Age { get; set; }
public UserInformation(UserEntity user) {
this.Name = user.name;
this.Age = user.age;
}
}
Then change your return type to: IEnumerable<UserInformation>
While all these answers above are correct, one may want to check the InnerException > ExceptionMessage.
If it says something like this "The ObjectContext instance has been disposed and can no longer be used for operations that require a connection.". This could be an issue because of default behavior of the EF.
By assigning LazyLoadingEnabled = false in your DbContext constructor will do the trick.
public class MyDbContext : DbContext
{
public MyDbContext()
{
this.Configuration.LazyLoadingEnabled = false;
}
}
For more detailed reading about EagerLoading and LazyLoading behavior of EF refer this MSDN Article.
In my case I have had similar error message:
The 'ObjectContent`1' type failed to serialize the response body for
content type 'application/xml; charset=utf-8'.
But when I dig deeper in it, the issue was:
Type 'name.SomeSubRootType'
with data contract name
'SomeSubRootType://schemas.datacontract.org/2004/07/WhatEverService'
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.
The way I solved by adding KnownType.
[KnownType(typeof(SomeSubRootType))]
public partial class SomeRootStructureType
This was solved inspired from this answer.
Reference: https://msdn.microsoft.com/en-us/library/ms730167(v=vs.100).aspx
I basically add one line which they are
entities.Configuration.ProxyCreationEnabled = false;
to UsersController.cs
using System;
using System.Collections.Generic;
using System.Linq;
using System.Net;
using System.Net.Http;
using System.Web.Http;
using UserDataAccess;
namespace SBPMS.Controllers
{
public class UsersController : ApiController
{
public IEnumerable<User> Get() {
using (SBPMSystemEntities entities = new SBPMSystemEntities()) {
entities.Configuration.ProxyCreationEnabled = false;
return entities.Users.ToList();
}
}
public User Get(int id) {
using (SBPMSystemEntities entities = new SBPMSystemEntities()) {
entities.Configuration.ProxyCreationEnabled = false;
return entities.Users.FirstOrDefault(e => e.user_ID == id);
}
}
}
}
You will have to define Serializer Formatter within WebApiConfig.cs available in App_Start Folder like
Adding config.Formatters.Remove(config.Formatters.XmlFormatter);
// which will provide you data in JSON Format
Adding config.Formatters.Remove(config.Formatters.JsonFormatter);
// which will provide you data in XML Format
Another case where I received this error was when my database query returned a null value but my user/view model type was set as non-nullable. For example, changing my UserModel field from int to int? resolved.
This also happens when the Response-Type is not public!
I returned an internal class as I used Visual Studio to generate me the type.
internal class --> public class
Visual Studio 2017 or 2019 is totally unthoughtful on this, because Visual Studio itself requires the output to be in json format, while Visual Studio's default format is "XmlFormat" (config.Formatters.XmlFormatter).
Visual Studio should do this automatically instead of giving developers so much trouble.
To correct this problem, go to the WebApiConfig.cs file, and add
var json = config.Formatters.JsonFormatter;
json.SerializerSettings.PreserveReferencesHandling = Newtonsoft.Json.PreserveReferencesHandling.Objects;
config.Formatters.Remove(config.Formatters.XmlFormatter);
after "config.MapHttpAttributeRoutes();" in the Register(HttpConfiguration config) method. This would allow your project to produce json output.
In my case I solved recreating the database.
I made some changes in a model and launching Update-Database in Package Manager Console I got the following Error:
"The ALTER TABLE statement conflicted with the FOREIGN KEY constraint "FK_dbo.Activities_dbo.Projects_ProjectId". The conflict occurred in database "TrackEmAllContext-20190530144302", table "dbo.Projects", column 'Id'."
In case: If adding code to WebApiConfig.cs or Global.asax.cs doesn't work for you:
.ToList();
Add .ToList() function.
I tried out every solution but following worked for me:
var allShops = context.shops.Where(s => s.city_id == id)**.ToList()**;
return allShops;
I hope, it helps.
in my case, it was fixed when I removed the virtual keyword before my navigation properties,
I mean the reference tables.
so I changed
public virtual MembershipType MembershipType { get; set; }
to:
public MembershipType MembershipType { get; set; }
I've got a pretty basic ASP.NET Core 2 Web App (no razor views, just MvcCore with json responses).
I'm trying to do a pretty simple GET request in Postman and my Controller Action isn't binding the query string parameters to my custom POCO.
here is a sample url which postman tries to hit: http://localhost:51459/orders?Query=iphone&MinimumPrice=22
public class OrderQuery
{
public string Query { get; set; }
public decimal? MinimumPrice { get; set; }
public decimal? MaximumPrice { get; set; }
}
[Route("orders")]
public class OrdersController : ControllerBase
{
[HttpGet("")]
public async Task<ActionResult> GetOrdersAsync(OrderQuery query)
{
// query.Query is null.
// all the properties of query are null.
}
}
Now I can step through the method (i.e. breakpoint is hit), so the route does get 'found' and 'handled'.
Secondly, I've also tried sprinkling [FromQuery] attributes on the properties in the POCO.
Lastly, I've tried changing the case in the request but I thought model biding is case insensitive.
Can anyone see what I'm doing wrong? Is there a particular middleware I should check to see if I've wired up/not wired up?
OMG # me :(
So the variable name in the method signature is query and the (string) querystring key is also query.
The model binding was getting confused with which query do I mean? The property of the OrderQuery class? Or trying to set the string to actual method variable, which it cannot do.
Solution: renamed the entire signature to: public async Task<ActionResult> GetOrdersAsync(OrderQuery orderQuery)
** Note the method signature variable name change **
Doh! :)
TL;DR; Don't name the POCO variable name to a form/querystring/route key.
I was working on ASP.NET MVC web API, I'm having this error:
The 'ObjectContent`1' type failed to serialize the response body for content type 'application/xml; charset=utf-8'.
My controller is:
public Employee GetEmployees()
{
Employee employees = db.Employees.First();
return employees;
}
why I m getting this error?
For me this was a problem with circular referencing.
The accepted answer did not work for me because it only changes the behaviour of the JSON formatter, but I was getting XML when I called the service from the browser.
To fix this, I switched off XML and forced only JSON to be returned.
In the Global.asax file, put the following lines at the top of your Application_Start method:
GlobalConfiguration.Configuration.Formatters.JsonFormatter.SerializerSettings.ReferenceLoopHandling = Newtonsoft.Json.ReferenceLoopHandling.Ignore;
GlobalConfiguration.Configuration.Formatters.Remove(GlobalConfiguration.Configuration.Formatters.XmlFormatter);
Now only JSON results will be returned. If you need XML results, you will need to find a different solution.
in your global.asax file, in the Application_start() method add this line:
GlobalConfiguration.Configuration.Formatters.JsonFormatter.SerializerSettings.ReferenceLoopHandling = Newtonsoft.Json.ReferenceLoopHandling.Ignore;
I hope that helps you!
I got the same problem. And I solved it. I put the default constructor to the DTO class.
Ex:
public class User
{
public User()
{
}
}
Hope it work with you!
Put this in constructor. Hope this solve the problem:
public MyController()
{
db.Configuration.ProxyCreationEnabled = false;
}
I found two solutions to this. The first and easiest to implement is to change any IEnumerables, ICollections to a type of List. The WebAPI can serialize this objects, it however cannot serialize interface types.
public class Store
{
[StringLength(5)]
public string Zip5 { get; set; }
public virtual List<StoreReport> StoreReports { get; set; } //use a list here
}
The other option is to not use the native JSON serializer and run this override in the Register method of the WebApi Config:
var json = config.Formatters.JsonFormatter;
json.SerializerSettings.PreserveReferencesHandling = Newtonsoft.Json.PreserveReferencesHandling.Objects;
config.Formatters.Remove(config.Formatters.XmlFormatter);
Solution is simple.
After LINQ query add .ToList() (or ToDictionary if need).
It will do eager loading than lazy loading of the data
**
this bug occur when calling from request web api/wcf/... from client side, but as side effect, you will need to include depending relations by include keyword.
**
public CustomerPortalContext()
: base("Name=CustomerPortalContext")
{
base.Configuration.ProxyCreationEnabled = false;
}
If you are working with EF, besides adding the code below on Global.asax
GlobalConfiguration.Configuration.Formatters.JsonFormatter.SerializerSettings.ReferenceLoopHandling = Newtonsoft.Json.ReferenceLoopHandling.Ignore;
GlobalConfiguration.Configuration.Formatters.Remove(GlobalConfiguration.Configuration.Formatters.XmlFormatter);
Dont`t forget to import
using System.Data.Entity;
Then you can return your own EF Models
please check the web api documentation for this problem, Handling Circular Object References
Regards
If you use web api with Entity Framework, a solution can be
Failed to serialize the response in Web API with Json
Basically, you need to create a model corresponding to each EF model, this removes dependencies between classes and allow easy serialization.
Code: (taken from the referenced link)
Create a UserModel
public class UserModel
{
public string FirstName { get; set; }
public string LastName { get; set; }
}
Change my method GetAll()
public IEnumerable<UserModel> GetAll()
{
using (Database db = new Database ())
{
List<UserModel> listOfUsers = new List<UserModel>();
UserModel userModel = new UserModel();
foreach(var user in db.Users)
{
userModel.FirstName = user.FirstName;
userModel.LastName = user.LastName;
listOfUsers.Add(userModel);
}
IEnumerable<UserModel> users = listOfUsers;
return users;
}
}
Default Entity 6 use XML to apis, in your project, find the file "Global.asax" File and add this line:
GlobalConfiguration.Configuration.Formatters.Remove(GlobalConfiguration.Configuration.Formatters.XmlFormatter);
This line remove the XML Formatter.
but if you found this problem with other entities/classes, you have to create a new DTO for each class, and if you have a lot of them, you can find a problem, also I think that create a DTO only for solving this problem is no the best way...
Did you try this?
var json = GlobalConfiguration.Configuration.Formatters.JsonFormatter;
json.SerializerSettings.PreserveReferencesHandling =
Newtonsoft.Json.PreserveReferencesHandling.All;
Regards
hmmm, Following may help.
I was getting the same exception, and in my case I was passing the actual poco entity created for entity code first. Since, it contains relation with other entities, I just created the viewmapper/dto entity on top of it to return.
It works fine now.
Poco Entity:
public class Tag
{
public int Id{get;set;}
public string Title{get;set;}
public IList<Location> Locations{get;set;}
}
ViewMapper/Dto
public class TagResultsViewMapper
{
public int Id{get;set;}
public string Title{get;set;}
//just remove the following relationship
//public IList<Location> Locations{get;set;}
}
Your question is quite similar to mine. You must not return data from database directly. For this, you must create Model and associate data you want show.
In my example, There are data about User that Json couldn't serialize, I had create a userModel and, in my API, I return userModel instead User from database.
The logic of convert or associate data between User and UserModel must be in API.
Failed to serialize the response in Web API with Json
This was the specific error I was getting back from my odata Web API call:
The 'ObjectContent`1' type failed to serialize the response
body for content type 'application/json; odata.metadata=minimal'.
I finally figured out that my dbContext class had a poorly formatted table name being assigned in onModelCreating.. so the SqlClient was dying looking for a table that didn't exist in my db!!
I have an MVC solution that contains a ServiceStack API alongside an MVC UI that makes calls to the API services. Some of those services are AutoQuery GET endpoints, and I'm running into a problem where the ServiceStack service picks up posted form values or unrelated querystring values and throws argument errors when I call the services.
I've tried a number of ways of calling the services:
using (var fooSvc = new HostContext.ResolveService<FooService>(HttpContext))
{
var foos = (QueryResponse<Foo>)fooSvc.Get(new Foos());
// Do stuff here
}
No dice. Posted form values screw it up and I get a System.FormatException saying Input string was not in a correct format on this line in my service:
var q = AutoQuery.CreateQuery(request, Request.GetRequestParams());
So I tried:
var foos = (QueryResponse<Foo>)HostContext.ServiceController.Execute(new Foos());
In this case, I get a System.NotImplementedException saying it couldn't find a Post(Foos) or Any(Foos) (the call in question is a GET).
I'm sure I'm missing something simply. Mythz, got another rescue for me?
EDIT: I hand-typed that code...the initial block had AutoQuery when I meant QueryResponse...
EDIT 2: Here is the general structure of my AutoQuery services. These are all GET on the service because those endpoints also need to support POST to create a resource. For example, I might have the URI at http:/service.com/api/users and want to be able to GET with AutoQuery or POST to create a new user.
[Authenticate]
public class UsersService : Service
{
public IAutoQuery AutoQuery { get; set; }
public object Get(Users request)
{
var q = AutoQuery.CreateQuery(request, Request.GetRequestParams());
// Here I add some other conditions to the query object to filter results based on the user's role, etc.
return AutoQuery.Execute(request, q);
}
[RequiredRole("Admin")]
public object Post(CreateUser request)
{
var user = request.ConvertTo<User>();
Db.Save(user);
return user;
}
}
When you call a Service you're just calling a method directly on the target instance. What does the method returns? It's unlikely it's AutoQuery<Foo> since it's not a valid type in ServiceStack:
var foos = (AutoQuery<Foo>)fooSvc.Get(new Foos());
If you're getting a FormatException check the QueryString param that's causing it. Something in the Request is incompatible with the AutoQuery field.
Did you create the method yourself because AutoQuery generates services using the Any method so that it can be called by any verb. If it's a Custom Service change it to Any.
Otherwise you can Execute the method with the current HTTP Request with:
var foos = (QueryResponse<Foo>)HostContext.ServiceController
.Execute(new Foos(), HttpContext.ToRequest());
You can also override what Verb that gets executed with:
var req = HttpContext.ToRequest();
req.Items[Keywords.InvokeVerb] = "GET";
var foos = (QueryResponse<Foo>)HostContext.ServiceController
.Execute(new Foos(), req);
Custom AutoQuery Implementation
If you have conflicted fields trying to forward the request I would just change them to use fields that don't conflict with AutoQuery request. But if you still want to continue using the conflicted fields you can create a
Custom AutoQuery Implementation that removes it from the AutoQuery services instead, e.g:
public class UsersService : Service
{
public IAutoQuery AutoQuery { get; set; }
public object Any(Users request)
{
Dictionary<string, string> args = Request.GetRequestParams();
args.Remove("OrganizationId");// E.g remove conflicted fields
var q = AutoQuery.CreateQuery(request, args);
return AutoQuery.Execute(request, q);
}
}
When using a FindOne() using MongoDB and C#, is there a way to ignore fields not found in the object?
EG, example model.
public class UserModel
{
public ObjectId id { get; set; }
public string Email { get; set; }
}
Now we also store a password in the MongoDB collection, but do not want to bind it to out object above. When we do a Get like so,
var query = Query<UserModel>.EQ(e => e.Email, model.Email);
var entity = usersCollection.FindOne(query);
We get the following error
Element 'Password' does not match any field or property of class
Is there anyway to tell Mongo to ignore fields it cant match with the models?
Yes. Just decorate your UserModel class with the BsonIgnoreExtraElements attribute:
[BsonIgnoreExtraElements]
public class UserModel
{
public ObjectId id { get; set; }
public string Email { get; set; }
}
As the name suggests, the driver would ignore any extra fields instead of throwing an exception. More information here - Ignoring Extra Elements.
Yet Another possible solution, is to register a convention for this.
This way, we do not have to annotate all classes with [BsonIgnoreExtraElements].
Somewhere when creating the mongo client, setup the following:
var pack = new ConventionPack();
pack.Add(new IgnoreExtraElementsConvention(true));
ConventionRegistry.Register("My Solution Conventions", pack, t => true);
Yes. Another way (instead of editing you model class) is to use RegisterClassMap with SetIgnoreExtraElements.
In your case just add this code when you initialize your driver:
BsonClassMap.RegisterClassMap<UserModel>(cm =>
{
cm.AutoMap();
cm.SetIgnoreExtraElements(true);
});
You can read more about ignoring extra elements using class mapping here - Ignoring Extra Elements.