I am using Refit 6.1.15 in a Xamarin forms project. My code works exactly as expected on Android, but on iOS, I get a "The type initializer for 'System.Text.Json.JsonSerializer' threw an exception." when I execute my api.
I am using Microsoft.Extensions for DI - my configuration of my service in my Startup.cs class looks like this:
services.AddRefitClient<IAuthorizeApi>()
.ConfigureHttpClient(c => c.BaseAddress = new Uri(BaseAddress))
.AddTransientHttpErrorPolicy(builder => builder.WaitAndRetryAsync(new[]
{
TimeSpan.FromSeconds(1),
TimeSpan.FromSeconds(5),
TimeSpan.FromSeconds(15)
}));
My IAuthorizeAPI looks like this:
using System;
using System.Threading.Tasks;
using CivicMobile.Models;
namespace CivicMobile.Services
{
public interface IAuthorizeApi
{
[Post("/v1/DataStage/UserAuthentication/Authenticate?companyCode={queryParms.companyCode}&username={queryParms.username}&password={queryParms.password}&deviceIdentifier={queryParms.deviceIdentifier}")]
[QueryUriFormat(UriFormat.Unescaped)]
Task<ApiResponse<AuthResponse>> Login(Authorize queryParms);
}
My call that throws the error (in my ViewModel) is:
var authToken = await _authenticateService.Login(queryParms);
The return value for the Login (wrapped in ApiResponse) looks like this:
namespace CivicMobile.Models
{
public class AuthResponse
{
[AliasAs("access_token")]
public string AccessToken { get; set; }
[AliasAs("token_type")]
public string TokenType { get; set; }
[AliasAs("expires_in")]
public int ExpiresIn { get; set; }
[AliasAs("userName")]
public string Username { get; set; }
[AliasAs("userIdentifier")]
public string UserIdentifier { get; set; }
[AliasAs(".issued")]
public string IssuedAt { get; set; }
[AliasAs(".expires")]
public string ExpiresAt { get; set; }
}
I have replaced [AliasAs()] with [JsonPropertyName()] but the results are the same.
This error ONLY occurs on iOS - not on Android. Any suggestions?
Add the following code in your iOS(.csproj ):
<ItemGroup>
<PackageReference Include="System.Memory" Version="4.5.4">
<IncludeAssets>none</IncludeAssets>
</PackageReference>
<PackageReference Include="System.Buffers" Version="4.5.1">
< IncludeAssets>none</IncludeAssets>
</PackageReference>
</ItemGroup>
I took refit out of my DI Container and the problem went away entirely. No other changes in my code at all. I will try another DI system as I prefer to use DI in this app and refit.
Another update - I had AddHttpClient as well as the AddRefitClient in my ConfigureServices method. It was actually dead code (as I migrated to Refit but never got rid of dead code). That caused my POST to return a proper ApiResponse object with Content that was deserialized properly. So back to what I had planned in the beginning - thanks for your suggestion - it was helpful on another issue (a very large dataset returning - different Api).
Related
I'm working on a new project that uses CosmosDB and Entity Framework Core (via the Microsoft.EntityFrameworkCore.Cosmos NuGet package, version 5.0.7; the project itself is .NET Core 5). I'm new to both, and running into an issue I can't sort out.
In short, I need to save a complex object to the database. It's a big model that will have multiple collections of classes underneath it, each with their own properties and some with collections underneath them as well. I'm trying to configure EF with OwnsOne and OwnsMany to store these child objects underneath the top-level one. The code compiles, and will save to the database so long as all the owned objects are left empty. But whenever I put anything into an owned object, either with OwnsOne or OwnsMany, I get a pair of NullReferenceExceptions.
I've tried to strip my code down to the very basics. Here's how it currently looks.
Owner and owned classes:
public class Questionnaire
{
// Constructors
private Questionnaire() { }
public Questionnaire(Guid id)
{
Test = "Test property.";
TV = new TestQ();
Id = id;
}
public Guid Id { get; set; }
public string Test { get; set; }
public TestQ TV { get; set; }
// Public Methods
public void AddForm(Form f)
{
// not currently using this method
//Forms.Add(f);
}
}
public class TestQ
{
public TestQ()
{
TestValue = "test ownsone value";
}
public string TestValue { get; set; }
}
DbContext:
public class QuestionnaireDbContext : DbContext
{
public DbSet<Questionnaire> Questionnaires { get; set; }
public QuestionnaireDbContext(DbContextOptions<QuestionnaireDbContext> options) : base(options) { }
protected override void OnModelCreating(ModelBuilder modelBuilder)
{
modelBuilder.HasDefaultContainer(nameof(Questionnaires));
modelBuilder.Entity<Questionnaire>().HasKey(q => q.Id);
modelBuilder.Entity<Questionnaire>().OwnsOne(q => q.TV);
}
}
And the code from the service that calls the dbContext (note that this is based on a generic service that I didn't set up originally). The actual exceptions are thrown here.
public virtual TEntity Add(TEntity entity)
{
_context.Entry(entity).State = EntityState.Added;
_context.SaveChanges();
return entity;
}
Ultimately I need this to work with OwnsMany and a collection, but I figured it might be simpler to get it working with OwnsOne first. The key thing to note here is that if I comment out the line
TV = new TestQ();
in the Questionnaire class, the model persists correctly into CosmosDB. It's only when I actually instantiate an owned entity that I get the NullReferenceExceptions.
Any advice would be much appreciated! Thank you!
Well, I'm not sure why this is the case, but the issue turned out to be with how we were adding the document. Using this generic code:
public virtual async Task<TEntity> Add(TEntity entity)
{
_context.Entry(entity).State = EntityState.Added;
await _context.SaveChanges();
return entity;
}
was the issue. It works just fine if I use the actual QuestionnaireDbContext class like so:
context.Add(questionnaire);
await context.SaveChangesAsync();
I'm using a C# 9.0 record type as a binding model for a .NET 5.0 Web API project. Some of the properties are required.
I'm using the record positional syntax, but am receiving errors.
public record Mail(
System.Guid? Id,
[property: Required]
string From,
[property: Required]
string[] Tos,
[property: Required]
string Subject,
string[]? Ccs,
string[]? Bccs,
[property: Required]
Content[] Contents,
Attachment[]? Attachments
);
This is then exposed as the binding model for my Index action:
public async Task<ActionResult> Index(Service.Models.Mail mailRequest)
{
…
}
Whenever I try to make a request, however, I receive the following error:
Record type 'Service.Models.Mail' has validation metadata defined on property 'Contents' that will be ignored. 'Contents' is a parameter in the record primary constructor and validation metadata must be associated with the constructor parameter.
I tried removing the attribute on the Contents property, but it then fails for the next (prior) property. I tried using [param: …] instead of [property: …], as well as mixing them, but keep getting the same kind of error.
I looked around the web, and haven't found any suggestion of handling annotations differently for C# 9 records. I did my best, but I'm out of ideas—outside of converting my records to POCOs.
I gave up using Positional constructor, and with the verbose full declaration of the properties, it works.
public record Mail
{
public System.Guid? Id { get; init; }
[Required]
public string From { get; init; }
[Required]
public string[] Tos { get; init; }
[Required]
public string Subject { get; init; }
public string[]? Ccs { get; init; }
public string[]? Bccs { get; init; }
[Required]
public Content[] Contents { get; init; }
public Attachment[]? Attachments { get; init; }
public Status? Status { get; init; }
public Mail(Guid? id, string #from, string[] tos, string subject, string[]? ccs, string[]? bccs, Content[] contents, Attachment[]? attachments, Status status)
{
Id = id;
From = #from;
Tos = tos;
Subject = subject;
Ccs = ccs;
Bccs = bccs;
Contents = contents;
Attachments = attachments;
Status = status;
}
}
Try using only [Required] (instead of [property: Required]), for some reason worked for me
For me it started to work by adding the [ApiController] attribute to the controller.
I found something similar on ASP.NET Core Razor pages getting:
InvalidOperationException: Record type 'WebApplication1.Pages.LoginModelNRTB+InputModel' has validation metadata defined on property 'PasswordB' that will be ignored. 'PasswordB' is a parameter in the record primary constructor and validation metadata must be associated with the constructor parameter.
from
Microsoft.AspNetCore.Mvc.ModelBinding.ModelMetadata.ThrowIfRecordTypeHasValidationOnProperties()
After some digging, I found: https://github.com/dotnet/aspnetcore/blob/main/src/Mvc/Mvc.Core/src/ModelBinding/Validation/DefaultComplexObjectValidationStrategy.cs
So maybe as you've done, the verbose declaration is the way forward.
Positional record attributes in ASP.NET Core background
How do I target attributes for a record class? more background
Using FluentValidation and keeping properties with the full declaration seems to work perfectly in my case. I highly recommend trying this highly polished alternative validation library instead of using the pretty old standard data annotations
public record LoginViewModel
{
public string Mail { get; init; }
public string Password { get; init; }
public bool IsPersistent { get; init; }
}
public class LoginValidator : AbstractValidator<LoginViewModel>
{
public LoginValidator()
{
RuleFor(l => l.Mail).NotEmpty().EmailAddress();
RuleFor(l => l.Password).NotEmpty();
}
}
I am trying to use ASP.Net OData v4 (e.g. ODataController) to allow access where the key is a string. 95% of the examples out there use an integer as a key and the couple of posts I've found that discuss the steps to use a string as the key aren't working for me.
In all cases, I am trying to access my resource with the following URL:
/api/ContactTypes('Agency')
Optimistically, I started with just changing the type of the key from int to key:
public SingleResult<ContactType> Get([FromODataUri] string key)
But I get a 404 response. Changing the URL to an integer, /api/ContactTypes(1) does "work" in that it routes to the correct method and that the key is a string type, but obviously, that doesn't help me. This is the scenario described in this post: How to get ASP.Net Web API and OData to bind a string value as a key? except that that post implies that accessing the URL the way I am should work (and also is for OData v3).
After further searching, I found this article: https://blogs.msdn.microsoft.com/davidhardin/2014/12/17/web-api-odata-v4-lessons-learned/ which basically says that you have to decorate the Get method with an explicit routing:
[ODataRoute("({key})")]
public SingleResult<ContactType> Get([FromODataUri] string key)
If I do that alone, though, I get "The path template '({key})' on the action 'Get' in controller 'ContactTypes' is not a valid OData path template. Empty segment encountered in request URL. Please make sure that a valid request URL is specified."
The comments in this post (https://damienbod.com/2014/06/16/web-api-and-odata-v4-crud-and-actions-part-3/) suggest that I need to decorate the Controller with an ODataRoutePrefix:
[ODataRoutePrefix("ContactTypes")]
public class ContactTypesController : ODataController
That seems counter-intuitive since I do not have anything ASP.Net should be confusing. My controller name is already following convention and I have no Web API controllers that could be confusing it.
Regardless, it does seem to "fix" the issue in that the error goes away, but then I am right back at square one (e.g. only integer values can be passed in the URL).
What am I missing?
Full controller code:
[Authorize]
[ODataRoutePrefix("ContactTypes")]
public class ContactTypesController : ODataController
{
PolicyContext _Db;
public ContactTypesController(PolicyContext db)
{
if (db == null)
throw new ArgumentNullException("db");
this._Db = db;
}
public ContactTypesController() : this(new PolicyContext())
{
}
protected override void Dispose(bool disposing)
{
_Db.Dispose();
base.Dispose(disposing);
}
[EnableQuery]
[ODataRoute()]
public IQueryable<ContactType> Get(ODataQueryOptions options)
{
return _Db.ContactType;
}
[EnableQuery]
[ODataRoute("({key})")]
public SingleResult<ContactType> Get([FromODataUri] string key)
{
IQueryable<ContactType> result = _Db.ContactType.Where(p => p.ContactTypeKey == key);
return SingleResult.Create(result);
}
Full WebApiConfig:
public static void Register(HttpConfiguration config)
{
// Web API configuration and services
// Web API routes
config.MapHttpAttributeRoutes();
builder.EntitySet<ContactType>("ContactTypes");
config.MapODataServiceRoute(
routeName: "ODataRoute",
routePrefix: "api",
model: builder.GetEdmModel()
);
}
1.If in your EdmModel, the string property is key, then no ODataRoute is need, for example:
public class Product
{
public string Id { get; set; }
public string Name { get; set; }
public double Price { get; set; }
}
ConventionModelBuilder will use property named "Id" as the key, or you should specify it's a key like:
public class Product
{
[Key]
public string StringKey { get; set; }
public string Name { get; set; }
public double Price { get; set; }
}
Then the call like localhost\api\Products('test') should just go to
public SingleResult<Product> GetProduct([FromODataUri]string key)
2.If you already have a int as a key, but you want use string as another key, then you should try this feature: http://odata.github.io/WebApi/#04-17-Alternate-Key , and you can call like:
localhost\api\Products(StringKey='test')
I am currently working on a Web API project with a Database-First method using Entity Framework (which I know is not the most stable of platforms yet), but I am running into something very strange.
When the GET method within my APIController tries to return all records in a DbSet with a LINQ Include() method involved such as this, it will return a 500 error:
// GET api/Casinos
public IEnumerable<casino> Getcasinos()
{
var casinos = db.casinos.Include(c => c.city).Include(c => c.state);
return casinos.AsEnumerable();
}
Yet, this method works fine, and returns my data from within my database:
// GET api/States
public IEnumerable<state> Getstates()
{
return db.states.AsEnumerable();
}
So I have proved in other instances that if it returns the entities without LINQ queries, it works great, yet when there is an Include method used upon the DbContext, it fails.
Of course, trying to find this error is impossible, even with Fiddler, Chrome/Firefox dev tools, and adding in GlobalConfiguration.Configuration.IncludeErrorDetailPolicy = IncludeErrorDetailPolicy.Always;
If anyone has resolved this, it would be nice to know a nice resolution so I can start returning my data! Thanks!:)
P.S. I am using SQL Server 2012
This is happening due to error in serialization (Json/XML). The problem is you are directly trying to transmit your Models over the wire. As an example, see this:
public class Casino
{
public int ID { get; set; }
public string Name { get; set; }
public virtual City City { get; set; }
}
public class State
{
public int ID { get; set; }
public string Name { get; set; }
[XmlIgnore]
[IgnoreDataMember]
public virtual ICollection<City> Cities { get; set; }
}
public class City
{
public int ID { get; set; }
public string Name { get; set; }
public virtual State State { get; set; }
[XmlIgnore]
[IgnoreDataMember]
public virtual ICollection<Casino> Casinos { get; set; }
}
public class Context : DbContext
{
public Context()
: base("Casino")
{
}
public DbSet<Casino> Casinos { get; set; }
public DbSet<State> States { get; set; }
public DbSet<City> Cities { get; set; }
}
Pay attention to the XmlIgnore and IgnoreDataMember. You need to restrict avoiding serialization so it doesn't happen in circular manner. Further, the above model will still not work because it has virtual. Remove virtual from everywhere namely City, Cities, Casinos and State and then it would work but that would be inefficient.
To sum up: Use DTOs and only send data that you really want to send instead of directly sending your models.
Hope this helps!
I had same problem in ASP.Net Core Web Api and made it working with this solution:
Add Microsoft.AspNetCore.Mvc.NewtonsoftJson nuget package to web api project.
and in Startup.cs class in ConfigureServices method add this code:
services.AddControllersWithViews().AddNewtonsoftJson(options =>
options.SerializerSettings.ReferenceLoopHandling = Newtonsoft.Json.ReferenceLoopHandling.Ignore
);
I am really struggling deserializing a PHP json encoded string in ASP.NET.
I am using nusoap and CakePHP 1.3 on the PHP side and mvc.net 4.0 on the web service side and everything was working well. However, I couldn’t figure out how to pass a complex array as one parameter of the webservice, so I had the idea of serializing it as json and passing a simple string. So far so good...
But I cannot for the life of me de-serialize the json_encoded string in ASP.NET [well, I’ve been trying for the last two hours at least ;)]
Here is what I have so far:
The PHP sends an array of products (product id as a GUID - sent as a string then converted on the web service side) and the number of products:
$args['products'] = json_encode($booking['Booking']['prs_products']);
This is received ok by the webservice as the following json string (products):
[{"BookingProducts":{"id":"2884f556-67ed-4eb8-98ca-a99dc27a2665","quantity":2}},{"BookingProducts":{"id":"f57854ba-0a9b-400b-bea0-bafdcb179b01","quantity":2}},{"BookingProducts":{"id":"7ff81128-c33c-4e6c-a33c-3ca40ccfb5d0","quantity":2}}]
I then try and populate a BookingProducts List<>. The BookingProducts class is as follows:
public class BookingProducts
{
public String id { get; set; }
public int quantity { get; set; }
public BookingProducts()
{
}
public BookingProducts(string id, int quantity)
{
this.id = id;
this.quantity = quantity;
}
}
I have tried both the [System.Web.Script.Serialization][2] and Newtonsoft.Json libraries as follows, but without success:
List<BookingProducts> productsList = new List<BookingProducts>();
try
{
productsList = JsonConvert.DeserializeObject<List<BookingProducts>>((products));
}
catch (Newtonsoft.Json.JsonSerializationException)
{
productsList = new JavaScriptSerializer().Deserialize<List<BookingProducts>>(products);
}
In both cases I get a list of empty products (or a serialization exception).
Hopefully someone has done this before, or can spot an obvious mistake!
What you really have here is a list of objects containing BookingProducts object. In order to deserialize it, you need to have something like this for your entity:
public class BookingProductsWrapper
{
public class BookingProductsInner
{
public string id { get; set; }
public int quantity { get; set; }
}
public BookingProductsInner BookingProducts { get; set; }
}
Now you can deserialize it using JavaScriptSerializer (for example):
System.Web.Script.Serialization.JavaScriptSerializer jsSerializer = new System.Web.Script.Serialization.JavaScriptSerializer();
List<BookingProductsWrapper> productsList = jsSerializer.Deserialize<List<BookingProductsWrapper>>(products);
That will do the trick.