I am building some services using ServiceStack, I have a following service
public class FooRequest: IReturn<FooResponse>
{
public int FooID { get; set; }
public decimal Amount { get; set; }
public string SortColumnName { get; set; }
}
public class FooResponse
{
private List<Payment> payments;
public FooResponse()
{
payments= new List<Payment>();
}
public List<Payment> Payments
{
get { return payments; }
set { payments = value; }
}
}
public class Payment
{
public int ID { get; set; }
public string Amount { get; set; } // Amount is formatted string based on the user language
public decimal PaymentAmount{ get; set; } // this is Alias for Amount
}
From above FooResponse, I don't want to show PaymentAmount in response/metadata.
If we make it as normal variable instead of property, it won't be visible in metadata. but that should be a property for other requirement.
Is it possible in ServiceStack to restrict some properties in response DTO?
Use the IgnoreDataMember attribute on the PaymentAmount property. Last time I checked ServiceStack was using and complying to the default .NET serialization attributes.
Related
I have a web API in my Blazor project. I have a method that looks like this:
[HttpGet("selected/{userId}/{max}", Name = "GetItems")]
public IList<ItemDto> GetItems(int userId, int max)
{
IList<ItemDto> Items = _itemsDatabaseController.GetItems(userId, max);
return Items?.Count > 0 ? Items : null;
}
Then I generated client code using NSwag Studio. It all worked fine until some days ago when suddenly my API method hangs after leaving the method (after I step over return and } in debugger just nothing happens).
I read somewhere it might be a problem with JSON serialization if you have nested objects in your DTOs, which I have. But its "just" that in ItemDto I have two other objects, I dont understand why it cant serialize that (if that is the problem at all).
Any ideas why it hangs?
These are my DTO's
public class ItemDto
{
public int ItemId { get; set; }
public int CompanyId { get; set; }
public int CustomerId { get; set; }
public int UserId { get; set; }
public CustomerDto CustomerData { get; set; }
}
public class CustomerDto
{
public int CustomerId { get; set; }
public int CustomerSettingsId { get; set; }
public ObjectDto ObjectData { get; set; }
}
public class ObjectDto
{
public int ObjectId { get; set; }
public string Reference { get; set; }
public DateTime? TimeCreated { get; set; }
public DateTime? TimeUpdated { get; set; }
}
I am running on .NET Core 3.0. I have not changed the JSON serializer and it should be the default one that is used by Blazor.
In my web API when I run project to get data from the database got this error
.net core 3.1
JsonException: A possible object cycle was detected which is not supported. This can either be due to a cycle or if the object depth is larger than the maximum allowed depth of 32.
These are my codes:
my Model
public class Product
{
public int Id { get; set; }
public string Name { get; set; }
public string ProductText { get; set; }
public int ProductCategoryId { get; set; }
[JsonIgnore]
public virtual ProductCategory ProductCategory { get; set; }
}
my productCategory class is:
public class ProductCategory
{
public int Id { get; set; }
public string Name { get; set; }
public string CatText { get; set; }
public string ImagePath { get; set; }
public int Priority { get; set; }
public int Viewd { get; set; }
public string Description { get; set; }
public bool Active { get; set; }
public DateTime CreateDate { get; set; }
public DateTime ModifyDate { get; set; }
public virtual ICollection<Product> Products { get; set; }
}
my repo is
public async Task<IList<Product>> GetAllProductAsync()
{
return await _context.Products.Include(p => p.ProductCategory).ToListAsync();
}
my interface
public interface IProductRepository
{
...
Task<IList<Product>> GetAllProductAsync();
...
}
and this is my controller in api project
[Route("api/[controller]")]
[ApiController]
public class ProductsController : ControllerBase
{
private readonly IProductRepository _productRepository;
public ProductsController(IProductRepository productRepository)
{
_productRepository = productRepository;
}
[HttpGet]
public ActionResult Get()
{
return Ok(_productRepository.GetAllProduct());
}
}
When I run API project and put this URL: https://localhost:44397/api/products
I got that error,
I can't resolve it
this is happening because your data have a reference loop.
e.g
// this example creates a reference loop
var p = new Product()
{
ProductCategory = new ProductCategory()
{ products = new List<Product>() }
};
p.ProductCategory.products.Add(p); // <- this create the loop
var x = JsonSerializer.Serialize(p); // A possible object cycle was detected ...
You can not handle the reference loop situation in the new System.Text.Json yet (netcore 3.1.1) unless you completely ignore a reference and its not a good idea always. (using [JsonIgnore] attribute)
but you have two options to fix this.
you can use Newtonsoft.Json in your project instead of System.Text.Json (i linked an article for you)
Download the System.Text.Json preview package version 5.0.0-alpha.1.20071.1 from dotnet5 gallery (through Visual Studio's NuGet client):
option 1 usage:
services.AddMvc()
.AddNewtonsoftJson(
options => {
options.SerializerSettings.ReferenceLoopHandling = ReferenceLoopHandling.Ignore;
});
// if you not using .AddMvc use these methods instead
//services.AddControllers().AddNewtonsoftJson(...);
//services.AddControllersWithViews().AddNewtonsoftJson(...);
//services.AddRazorPages().AddNewtonsoftJson(...);
option 2 usage:
// for manual serializer
var options = new JsonSerializerOptions
{
ReferenceHandling = ReferenceHandling.Preserve
};
string json = JsonSerializer.Serialize(objectWithLoops, options);
// -----------------------------------------
// for asp.net core 3.1 (globaly)
services.AddMvc()
.AddJsonOptions(o => {
o.JsonSerializerOptions
.ReferenceHandling = ReferenceHandling.Preserve
});
these serializers have ReferenceLoopHandling feature.
Edit : ReferenceHandling changed to ReferenceHandler in DotNet 5
but if you decide to just ignore one reference use [JsonIgnore] on one of these properties. but it causes null result on your API response for that field even when you don't have a reference loop.
public class Product
{
public int Id { get; set; }
public string Name { get; set; }
public string ProductText { get; set; }
public int ProductCategoryId { get; set; }
// [JsonIgnore] HERE or
public virtual ProductCategory ProductCategory { get; set; }
}
public class ProductCategory
{
public int Id { get; set; }
// [JsonIgnore] or HERE
public ICollection<Product> products {get;set;}
}
.NET 5 Web API
public static void ConfigureServices(this IServiceCollection services, IConfiguration configuration)
{
services.AddControllers()
.AddJsonOptions(o => o.JsonSerializerOptions
.ReferenceHandler = ReferenceHandler.Preserve);
}
I have the same issue, my fix was to add async and await keyword since I am calling an async method on my business logic.
Here is my original code:
[HttpGet]
public IActionResult Get()
{
//This is async method and I am not using await and async feature .NET which triggers the error
var results = _repository.GetAllDataAsync();
return Ok(results);
}
To this one:
HttpGet]
public async Task<IActionResult> Get()
{
var results = await _repository.GetAllDataAsync();
return Ok(results);
}
In .Net 6, you can use System.Text.Json to initialize a startup action with AddControllersWithViews like this in Program.cs,
using System.Text.Json.Serialization;
builder.Services.AddControllersWithViews()
.AddJsonOptions(x => x.JsonSerializerOptions.ReferenceHandler = ReferenceHandler.IgnoreCycles);
also you can use AddMvc like this,
builder.Services.AddMvc()
.AddJsonOptions(x => x.JsonSerializerOptions.ReferenceHandler = ReferenceHandler.IgnoreCycles);
but quote from Ryan
asp.net core 3.0+ template use these new
methodsAddControllersWithViews,AddRazorPages,AddControllers instead of
AddMvc.
I will recommend to use the first solution.
Ensure you have [JsonIgnore] on the correct fields to avoid a circular reference.
In this case you will need
public class Product
{
public int Id { get; set; }
public string Name { get; set; }
public string ProductText { get; set; }
[JsonIgnore]
public virtual ProductCategory ProductCategory { get; set; }
}
You probably don't need the ProductCategoryId field (depends if you are using EF and code first to define your DB)
Edit - In answer to noruk
There is often confusion in connected objects and navigation properties. You can get the data you want in JSON but also define the EF structures to get the correct DB structure (foreign keys, indexes, etc).
Take this simple example. A Product (for example a T-Shirt) has many sizes or SKUs (e.g. Small, Large, etc)
public class Product
{
[Key]
[MaxLength(50)]
public string Style { get; set; }
[MaxLength(255)]
public string Description { get; set; }
public List<Sku> Skus { get; set; }
}
public class Sku
{
[Key]
[MaxLength(50)]
public string Sku { get; set; }
[MaxLength(50)]
public string Barcode { get; set; }
public string Size { get; set; }
public decimal Price { get; set; }
// One to Many for Product
[JsonIgnore]
public Product Product { get; set; }
}
Here you can serialise a Product and the JSON data will include the SKUs. This is the normal way of doing things.
However if you serialise a SKU you will NOT get it's parent product. Including the navigation property will send you into the dreaded loop and throw the "object cycle was detected" error.
I know this is limiting in some use cases but I would suggest you follow this pattern and if you want the parent object available you fetch it separately based on the child.
var parent = dbContext.SKUs.Include(p => p.Product).First(s => s.Sku == "MY SKU").Product
I fixed my API Core Net6.0 adding [JsonIgnore]:
public class SubCategoryDto
{
public int Id { get; set; }
public string Name { get; set; }
public string Image { get; set; }
public int CategoryId { get; set; }
[JsonIgnore]
public Category Category { get; set; }
}
For net core 3.1 you have to add in Startup.cs:
services.AddMvc.AddJsonOptions(o => {
o.JsonSerializerOptions.ReferenceHandler = ReferenceHandler.Preserve;
o.JsonSerializerOptions.MaxDepth = 0;
})
and import at least this package using nuget.org include prerelease:
<PackageReference Include="System.Text.Json" Version="5.0.0-rc.1.20451.14" />
following code is working for me in dotnet 5.0 :
services.AddControllersWithViews()
.AddJsonOptions(o => o.JsonSerializerOptions
.ReferenceHandler = ReferenceHandler.Preserve);
Finally fixed mine with System.Text.Json not NewtonSoft.Json using
var options = new JsonSerializerOptions()
{
MaxDepth = 0,
IgnoreNullValues = true,
IgnoreReadOnlyProperties = true
};
Using options to serialize
objstr = JsonSerializer.Serialize(obj,options);
My project built with a similar error.
Here's the code before
public class PrimaryClass {
public int PrimaryClassId
public ICollection<DependentClass> DependentClasses { get; set; }
}
public class DependentClass {
public int DependentClassId { get; set; }
public int PrimaryClassId { get; set; }
public PrimaryClass primaryClass { get; set; }
}
I took away the PrimaryClass object from the DependentClass model.
Code after
public class PrimaryClass {
public int PrimaryClassId
public ICollection<DependentClass> DependentClasses { get; set; }
}
public class DependentClass {
public int DependentClassId { get; set; }
public int PrimaryClassId { get; set; }
}
I also had to adjust the OnModelCreating method from
modelBuilder.Entity<PrimaryClass>().HasMany(p => p.DependentClasses).WithOne(d => d.primaryClass).HasForeignKey(d => d.PrimaryClassId);
to
modelBuilder.Entity<PrimaryClass>().HasMany(p => p.DependentClasses);
The DbSet query that's running is
public async Task<List<DependentClass>> GetPrimaryClassDependentClasses(PrimaryClass p)
{
return await _dbContext.DependentClass.Where(dep => dep.PrimaryClassId == p.PrimaryClassId).ToListAsync();
}
The error could have been with any of these 3 sections of code, but removing the primary object reference from the dependent class and adjusting the OnModelCreating resolved the error, I'm just not sure why that would cause a cycle.
In my case the problem was when creating the entity relationships. I linked the main entity using a foreign key inside the dependent entity like this
[ForeignKey("category_id")]
public Device_Category Device_Category { get; set; }
also I referred the dipendend entity inside the main entity as well.
public List<Device> devices { get; set; }
which created a cycle.
Dependent Entity
public class Device
{
[Key]
public int id { get; set; }
public int asset_number { get; set; }
public string brand { get; set; }
public string model_name { get; set; }
public string model_no { get; set; }
public string serial_no { get; set; }
public string os { get; set; }
public string os_version { get; set; }
public string note { get; set; }
public bool shared { get; set; }
public int week_limit { get; set; }
public bool auto_acceptance { get; set; }
public bool booking_availability { get; set; }
public bool hide_device { get; set; }
public bool last_booked_id { get; set; }
//getting the relationships category 1 to many
public int category_id { get; set; }
[ForeignKey("category_id")]
public Device_Category Device_Category { get; set; }
public List<Booking> Bookings { get; set; }
}
Main Entity
public class Device_Category
{
public int id { get; set; }
public string name { get; set; }
public List<Device> devices { get; set; }
}
}
So I commented the
public List<Device> devices { get; set; }
inside main entity (Device_Category) and problem solved
I have a Web API Controller in my Asp.Net Core Web API 2.2 project.
Messageboard model:
public class MessageBoard
{
public long Id { get; set; }
public string Name { get; set; }
public string Description { get; set; }
public ICollection<Message> Messages { get; set; }
}
Message model:
public class Message
{
public long Id { get; set; }
public string Text { get; set; }
public string User { get; set; }
public DateTime PostedDate { get; set; }
public long MessageBoardId { get; set; }
[ForeignKey("MessageBoardId")]
public MessageBoard MessageBoard { get; set; }
}
This is one of my Web API Controller actions, shortened for brevity:
[Route("api/[controller]")]
[ApiController]
public class MessageBoardsController : ControllerBase
{
// GET: api/MessageBoards
[HttpGet]
public async Task<ActionResult<IEnumerable<MessageBoard>>> GetMessageBoards()
{
return await _context.MessageBoards
.Include(i => i.Messages)
.ToListAsync();
}
}
Whenever I issue a GET request to MessageBoards, only part of the correct JSON is returned. Here is the returned JSON from accessing https://localhost:44384/api/MessageBoards/ on Postman:
[{"id":1,"name":"Test Board 2","description":"A 2nd Message board for
testing purposes.","messages":[{"id":1,"text":"Posting my first
message!","user":"Jesse","postedDate":"2019-01-01T00:00:00","messageBoardId":1
The JSON is cut-off (hence why it's an ugly block and not beautified by Postman), presumably due to the MessageBoard property on the Message model since it is the first missing JSON item.
How can I make the action correctly return the list of MessageBoards and child Messages?
I see you are using Eager Loading in your query. So add the following configuration in your Startup class to ignore cycles that it finds in the object graph and to generate JSON response properly.
public void ConfigureServices(IServiceCollection services)
{
...
services.AddMvc()
.AddJsonOptions(
options => options.SerializerSettings.ReferenceLoopHandling = Newtonsoft.Json.ReferenceLoopHandling.Ignore
);
...
}
For more details:
Related data and serialization in EF Core
The selected answer was correct in my case as well, my JSON response was getting truncated by a reference loop in my JSON response, and setting ReferenceLoopHandling.Ignore did indeed solve my issue. However, this is not the best solution in my opinion, as this maintains the circular references in your model. A better solution would use the [JsonIgnore] attribute within the model.
The issue in your model is here:
public class MessageBoard
{
public long Id { get; set; }
public string Name { get; set; }
public string Description { get; set; }
public ICollection<Message> Messages { get; set; }
}
public class Message
{
public long Id { get; set; }
public string Text { get; set; }
public string User { get; set; }
public DateTime PostedDate { get; set; }
public long MessageBoardId { get; set; }
[ForeignKey("MessageBoardId")]
public MessageBoard MessageBoard { get; set; } //This is the cause of your circular referece!!!
}
As you can see, your MessageBoard navigation property is where this response is truncated. Specifically, it will cause each Message in the json response to contain all of the MessageBoard information for each Message entry in the response. Newtonsoft does not like this. The solution is to simply [JsonIngore] the navigation properties that cause this circular reference. In your code this would be:
public class MessageBoard
{
public long Id { get; set; }
public string Name { get; set; }
public string Description { get; set; }
public ICollection<Message> Messages { get; set; }
}
public class Message
{
public long Id { get; set; }
public string Text { get; set; }
public string User { get; set; }
public DateTime PostedDate { get; set; }
public long MessageBoardId { get; set; }
[JsonIgnore]
[ForeignKey("MessageBoardId")]
public MessageBoard MessageBoard { get; set; } //fixed!!!
}
Try to create and return a DTO or a new struct/class that will not have cyclic info (MessageBoard has Message that has MessageBoard etc...)
[HttpPost]
public IHttpActionResult Post([FromBody]Stock stock)
public class Stock
{
public int DealerId { get; set; }
public int StockId { get; set; }
public long Kms { get; set; }
public DateTime MfgYear { get; set; }
}
Sample JSON request:
{
"stock":
{
"DealerId ":234,
"StockId ":123,
"Kms":12324,
"versionId":987,
"MfgYear":2010,
}
}
I need to change c# Stock class variable names i.e. from Kms to Kilometer, MfgYear to ManufacturingYear etc.
When i am posting data from postman to my Stock api, I need to have same parameters in c# as i have it in my json. Is there any way i can change this mapping that would allow me to map json Kms to C# Kilometer?
Simply use the JsonPropertyAttribute:
[JsonProperty(PropertyName = "Kms")]
public int Kilometer { get; set; }
I've created a simple .NET backend mobile azure service in C#. I have the mobile service up and running (all it's doing currently is working with your normal CRUD on a single table). The problem I'm having is that the PATCH/UPDATE will not do as it says. I can do everything else I've tried, SELECT, INSERT, DELETE, but I've been unable to update data.
When I debug into the block of code that calls UpdateAsync, the patch.GetEntity()..... always has the values NULL or zeroed out or day one datetimes, like it's not passing along the property values of what I'm trying to update. The only value I ever have is the correct id. Below I tried to strip out some of the code I have, I used some of what was in the first few tutorials on the Azure website.
I have a Data Object:
public class AdminLookupDATA: EntityData
{
public string description { get; set; }
public int lookuptype { get; set; }
public int priority { get; set; }
public bool inactive { get; set; }
public DateTime createdate { get; set; }
public DateTime editdate { get; set; }
}
I have a DTO:
public class AdminLookupDTO
{
public string id { get; set; }
public string description { get; set; }
public int lookuptype { get; set; }
public int priority { get; set; }
public bool inactive { get; set; }
public DateTime createdate { get; set; }
public DateTime editdate { get; set; }
}
I have a Model:
public class AdminLookupModel
{
public string Id { get; set; }
public string description { get; set; }
public int lookuptype { get; set; }
public int priority { get; set; }
public bool inactive { get; set; }
public DateTime createdate { get; set; }
public DateTime editdate { get; set; }
}
My PATCH inside my controller:
public Task<AdminLookupDATA> PatchAdminLookupDATA(string id, Delta<AdminLookupDATA> patch)
{
return UpdateAsync(id, patch);
}
Also, I have the same issue if I try to run the PATCH function directly from the browser in the "try it out" section, so it's something I have configured wrong within the service project itself. Any suggestions would be greatly appreciated.
Thanks,
Rob
Your property names must start with a capital letter.
Otherwise configure the CamelCasePropertyNamesContractResolver as indicated here:
http://odetocode.com/blogs/scott/archive/2013/03/25/asp-net-webapi-tip-3-camelcasing-json.aspx
code snippet
var formatters = GlobalConfiguration.Configuration.Formatters;
var jsonFormatter = formatters.JsonFormatter;
var settings = jsonFormatter.SerializerSettings;
settings.Formatting = Formatting.Indented;
settings.ContractResolver = new CamelCasePropertyNamesContractResolver();