How to parse attribute in JsonConvert.DeserializeObject - json.net

We have following JSON output from an API.
We are using the following code in ASP.NET to deserialize a JSON response to a class:
var j = JsonConvert.DeserializeObject<classname>(response);
While deserializing the following JSON, we are unable to get the attribute values.
{
"User": {
"Address": {
"#CityName": "Test",
"$": "B4C99EB0-18E6-439F-882A-9E4A11E1FF75"
}
}
}
As per the above example we need to get #cityname and $ attribute values.
We need following output in the class:
#CityName : Test
$ : B4C99EB0-18E6-439F-882A-9E4A11E1FF75
I am getting the element value, but I am not able to get the attribute values.
Is there a way I can do this?

You can use the [JsonProperty] attribute to map non-standard JSON property names to properties in your class. Make your classes like this:
public class RootObject
{
public User User { get; set; }
}
public class User
{
public Address Address { get; set; }
}
public class Address
{
[JsonProperty("#CityName")]
public string CityName { get; set; }
[JsonProperty("$")]
public string Guid { get; set; }
}
Then deserialize like this:
var obj = JsonConvert.DeserializeObject<RootObject>(response);

Related

How to get API response key values in PascalCase as same as the object variable name in .net core 3.1 only for one controller or one function?

This is my Object Class
public class MyObject
{
Public string Var1 { get; set; }
Public string Var2 { get; set; }
}
This is a get function of my controller class
[HttpGet]
public IActionResult GetObjList()
{
return Ok(new GenericModel<List<MyObject>>
{
Data = myobjectList
});
}
The GenericModel contains
public class GenericModel<T>
{
public T Data { get; set; }
public string[] Errors { get; set; }
}
My expected result look like this
{
"Data": [
{
"Var1": "val1",
"Var2": "val2"
}
]
}
But I'm getting this,
{
"data": [
{
"var1": "val1",
"var2": "val2"
}
]
}
I just want to get the output key values as same as the object variables, (in PascalCase)
I tried the solutions to add "AddJsonOptions" into the Startup.cs but they did not work. And I want the response as Pascal case, only for this controller requests, not in all requests including other controllers. (Sounds odd, but I want to try it) Are there any solutions? Is is impossible?
There may be another solution but I suggest building ContentResult yourself with JsonSerializer:
[HttpGet]
public IActionResult GetObjList()
{
return this.Content(JsonSerializer.Serialize(yourResult, yourJsonOption), "application/json");
}
For Pascal Case serialization use this code in Startup.cs:
services.AddControllers().AddJsonOptions(options =>
{
options.JsonSerializerOptions.PropertyNamingPolicy= null;
);

Out-only field in JSON deserialization [duplicate]

We have some configuration files which were generated by serializing C# objects with Json.net.
We'd like to migrate one property of the serialised class away from being a simple enum property into a class property.
One easy way to do this, would be to leave the old enum property on the class, and arrange for Json.net to read this property when we load the config, but not to save it again when we next serialize the object. We'll deal with generating the new class from the old enum separately.
Is there any simple way to mark (e.g. with attributes) a property of a C# object, so that Json.net will ignore it ONLY when serializing, but attend to it when deserializing?
There are actually several fairly simple approaches you can use to achieve the result you want.
Let's assume, for example, that you have your classes currently defined like this:
class Config
{
public Fizz ObsoleteSetting { get; set; }
public Bang ReplacementSetting { get; set; }
}
enum Fizz { Alpha, Beta, Gamma }
class Bang
{
public string Value { get; set; }
}
And you want to do this:
string json = #"{ ""ObsoleteSetting"" : ""Gamma"" }";
// deserialize
Config config = JsonConvert.DeserializeObject<Config>(json);
// migrate
config.ReplacementSetting =
new Bang { Value = config.ObsoleteSetting.ToString() };
// serialize
json = JsonConvert.SerializeObject(config);
Console.WriteLine(json);
To get this:
{"ReplacementSetting":{"Value":"Gamma"}}
Approach 1: Add a ShouldSerialize method
Json.NET has the ability to conditionally serialize properties by looking for corresponding ShouldSerialize methods in the class.
To use this feature, add a boolean ShouldSerializeBlah() method to your class where Blah is replaced with the name of the property that you do not want to serialize. Make the implementation of this method always return false.
class Config
{
public Fizz ObsoleteSetting { get; set; }
public Bang ReplacementSetting { get; set; }
public bool ShouldSerializeObsoleteSetting()
{
return false;
}
}
Note: if you like this approach but you don't want to muddy up the public interface of your class by introducing a ShouldSerialize method, you can use an IContractResolver to do the same thing programmatically. See Conditional Property Serialization in the documentation.
Approach 2: Manipulate the JSON with JObjects
Instead of using JsonConvert.SerializeObject to do the serialization, load the config object into a JObject, then simply remove the unwanted property from the JSON before writing it out. It's just a couple of extra lines of code.
JObject jo = JObject.FromObject(config);
// remove the "ObsoleteSetting" JProperty from its parent
jo["ObsoleteSetting"].Parent.Remove();
json = jo.ToString();
Approach 3: Clever (ab)use of attributes
Apply a [JsonIgnore] attribute to the property that you do not want to be serialized.
Add an alternate, private property setter to the class with the same type as the original property. Make the implementation of that property set the original property.
Apply a [JsonProperty] attribute to the alternate setter, giving it the same JSON name as the original property.
Here is the revised Config class:
class Config
{
[JsonIgnore]
public Fizz ObsoleteSetting { get; set; }
[JsonProperty("ObsoleteSetting")]
private Fizz ObsoleteSettingAlternateSetter
{
// get is intentionally omitted here
set { ObsoleteSetting = value; }
}
public Bang ReplacementSetting { get; set; }
}
For any situation where it's acceptable to have your deserialization-only property be marked internal, there's a remarkably simple solution that doesn't depend on attributes at all. Simply mark the property as internal get, but public set:
public class JsonTest {
public string SomeProperty { internal get; set; }
}
This results in correct deserialization using default settings/resolvers/etc., but the property is stripped from serialized output.
I like sticking with attributes on this one, here is the method I use when needing to deserialize a property but not serialize it or vice versa.
STEP 1 - Create the custom attribute
public class JsonIgnoreSerializationAttribute : Attribute { }
STEP 2 - Create a custom Contract Reslover
class JsonPropertiesResolver : DefaultContractResolver
{
protected override List<MemberInfo> GetSerializableMembers(Type objectType)
{
//Return properties that do NOT have the JsonIgnoreSerializationAttribute
return objectType.GetProperties()
.Where(pi => !Attribute.IsDefined(pi, typeof(JsonIgnoreSerializationAttribute)))
.ToList<MemberInfo>();
}
}
STEP 3 - Add attribute where serialization is not needed but deserialization is
[JsonIgnoreSerialization]
public string Prop1 { get; set; } //Will be skipped when serialized
[JsonIgnoreSerialization]
public string Prop2 { get; set; } //Also will be skipped when serialized
public string Prop3 { get; set; } //Will not be skipped when serialized
STEP 4 - Use it
var sweet = JsonConvert.SerializeObject(myObj, new JsonSerializerSettings { ContractResolver = new JsonPropertiesResolver() });
Hope this helps! Also it's worth noting that this will also ignore the properties when Deserialization happens, when I am derserializing I just use the converter in the conventional way.
JsonConvert.DeserializeObject<MyType>(myString);
Use setter property:
[JsonProperty(nameof(IgnoreOnSerializing))]
public string IgnoreOnSerializingSetter { set { _ignoreOnSerializing = value; } }
[JsonIgnore]
private string _ignoreOnSerializing;
[JsonIgnore]
public string IgnoreOnSerializing
{
get { return this._ignoreOnSerializing; }
set { this._ignoreOnSerializing = value; }
}
Hope this help.
After i spent a quite long time searching how to flag a class property to be De-Serializable and NOT Serializable i found that there's no such thing to do that at all; so i came up with a solution that combines two different libraries or serialization techniques (System.Runtime.Serialization.Json & Newtonsoft.Json) and it worked for me like the following:
flag all your class and sub-classes as "DataContract".
flag all the properties of your class and sub-classes as "DataMember".
flag all the properties of your class and sub-classes as "JsonProperty" except those you want them not to be serialized.
now flag the properties the you do NOT want it to be serialized as "JsonIgnore".
then Serialize using "Newtonsoft.Json.JsonConvert.SerializeObject" and De-Serialize using "System.Runtime.Serialization.Json.DataContractJsonSerializer".
using System;
using System.Collections.Generic;
using Newtonsoft.Json;
using System.Runtime.Serialization;
using System.IO;
using System.Runtime.Serialization.Json;
using System.Text;
namespace LUM_Win.model
{
[DataContract]
public class User
{
public User() { }
public User(String JSONObject)
{
MemoryStream stream = new MemoryStream(Encoding.Unicode.GetBytes(JSONObject));
DataContractJsonSerializer dataContractJsonSerializer = new DataContractJsonSerializer(typeof(User));
User user = (User)dataContractJsonSerializer.ReadObject(stream);
this.ID = user.ID;
this.Country = user.Country;
this.FirstName = user.FirstName;
this.LastName = user.LastName;
this.Nickname = user.Nickname;
this.PhoneNumber = user.PhoneNumber;
this.DisplayPicture = user.DisplayPicture;
this.IsRegistred = user.IsRegistred;
this.IsConfirmed = user.IsConfirmed;
this.VerificationCode = user.VerificationCode;
this.Meetings = user.Meetings;
}
[DataMember(Name = "_id")]
[JsonProperty(PropertyName = "_id")]
public String ID { get; set; }
[DataMember(Name = "country")]
[JsonProperty(PropertyName = "country")]
public String Country { get; set; }
[DataMember(Name = "firstname")]
[JsonProperty(PropertyName = "firstname")]
public String FirstName { get; set; }
[DataMember(Name = "lastname")]
[JsonProperty(PropertyName = "lastname")]
public String LastName { get; set; }
[DataMember(Name = "nickname")]
[JsonProperty(PropertyName = "nickname")]
public String Nickname { get; set; }
[DataMember(Name = "number")]
[JsonProperty(PropertyName = "number")]
public String PhoneNumber { get; set; }
[DataMember(Name = "thumbnail")]
[JsonProperty(PropertyName = "thumbnail")]
public String DisplayPicture { get; set; }
[DataMember(Name = "registered")]
[JsonProperty(PropertyName = "registered")]
public bool IsRegistred { get; set; }
[DataMember(Name = "confirmed")]
[JsonProperty(PropertyName = "confirmed")]
public bool IsConfirmed { get; set; }
[JsonIgnore]
[DataMember(Name = "verification_code")]
public String VerificationCode { get; set; }
[JsonIgnore]
[DataMember(Name = "meeting_ids")]
public List<Meeting> Meetings { get; set; }
public String toJSONString()
{
return JsonConvert.SerializeObject(this, new JsonSerializerSettings() { NullValueHandling = NullValueHandling.Ignore });
}
}
}
Hope that helps ...
Depending on where in the application this takes place and if it's just one property, one manual way you can do this is by setting the property value to null and then on the model you can specify that the property be ignored if the value is null:
[JsonProperty(NullValueHandling = NullValue.Ignore)]
public string MyProperty { get; set; }
If you are working on an ASP.NET Core web app, you can globally set this for all properties in all models by setting this in your Startup.cs file:
public void ConfigureServices(IServiceCollection services) {
// other configuration here
services.AddMvc()
.AddJsonOptions(options => options.SerializerSettings.NullValueHandling = NullValueHandling.Ignore);
}
with reference to #ThoHo's solution, using the setter is actually all that is needed, with no additional tags.
For me I previously had a single reference Id, that I wanted to load and add to the new collection of reference Ids. By changing the definition of the reference Id to only contain a setter method, which added the value to the new collection. Json can't write the value back if the Property doesn't have a get; method.
// Old property that I want to read from Json, but never write again. No getter.
public Guid RefId { set { RefIds.Add(value); } }
// New property that will be in use from now on. Both setter and getter.
public ICollection<Guid> RefIds { get; set; }
This class is now backwards compatible with the previous version and only saves the RefIds for the new versions.
To build upon Tho Ho's answer, this can also be used for fields.
[JsonProperty(nameof(IgnoreOnSerializing))]
public string IgnoreOnSerializingSetter { set { IgnoreOnSerializing = value; } }
[JsonIgnore]
public string IgnoreOnSerializing;
If you use JsonConvert,IgnoreDataMemberAttribute is ok.My standard library not refrence Newton.Json,and I use [IgnoreDataMember] to control object serialize.
From Newton.net help document.
Is there any simple way to mark (e.g. with attributes) a property of a C# object, so that Json.net will ignore it ONLY when serializing, but attend to it when deserializing?
The easiest way I've found as of this writing is to include this logic in your IContractResolver.
Sample code from above link copied here for posterity:
public class Employee
{
public string Name { get; set; }
public Employee Manager { get; set; }
public bool ShouldSerializeManager()
{
// don't serialize the Manager property if an employee is their own manager
return (Manager != this);
}
}
public class ShouldSerializeContractResolver : DefaultContractResolver
{
public new static readonly ShouldSerializeContractResolver Instance = new ShouldSerializeContractResolver();
protected override JsonProperty CreateProperty(MemberInfo member, MemberSerialization memberSerialization)
{
JsonProperty property = base.CreateProperty(member, memberSerialization);
if (property.DeclaringType == typeof(Employee) && property.PropertyName == "Manager")
{
property.ShouldSerialize =
instance =>
{
Employee e = (Employee)instance;
return e.Manager != e;
};
}
return property;
}
}
All of the answers are good but this approach seemed like the cleanest way. I actually implemented this by looking for an attribute on the property for SkipSerialize and SkipDeserialize so you can just mark up any class you control. Great question!
Jraco11's answer is very neat. In case, if you want to use the same IContractResolver both for serialization and deserialization, then you can use the following:
public class JsonPropertiesResolver : DefaultContractResolver
{
protected override JsonProperty CreateProperty(MemberInfo member, MemberSerialization memberSerialization)
{
JsonProperty property = base.CreateProperty(member, memberSerialization);
if (member.IsDefined(typeof(JsonIgnoreSerializationAttribute)))
{
property.ShouldSerialize = instance => false;
}
return property;
}
}
thats will do the trick, create a property with set only
example 1:
https://dotnetfiddle.net/IxMXcG
[JsonProperty("disabled-protections")]
public JArray DisabledProtections { set => IsPartialResult = (value != null && value.HasValues); }
public bool IsPartialResult { get; private set; }
example 2:
private JArray _disabledProtections;
[JsonProperty("disabled-protections")]
public JArray DisabledProtections { set => _disabledProtections = value; }
public bool IsPartialResult => _disabledProtections != null && _disabledProtections.HasValues;
Use [JsonIgnore] attribute in the public property of the model class.

How to get class name in nested fluentvalidation validators

I am trying to implement a complex nested validator using FluentValidation in .Net Core. Suppose there's a failure in one of the nested validators and the error messages are available at validationResult.Errors. I was wondering if is there a way that I can access the name of the object that has the error.
Entities
Constituent
public class Constituent : BaseAuditedEntity
{
[Required]
[MaxLength(50)]
public string ClientProspectID { get; set; }
[InverseProperty("Client")]
public virtual ICollection<Solicit> Solicits { get; set; }
}
Solicit
public class Solicit: BaseAuditedEntity
{
[Required]
[ForeignKey("Client")]
public long ClientId { get; set; }
public StudyType StudyType { get; set; }
public virtual Constituent Client { get; set; }
}
Validators
ConstituentValidator and its nested SolicitValidator
public class ConstituentValidator : AbstractValidator<Constituent>
{
public ConstituentValidator()
{
RuleFor(x => x.ClientProspectID).NotEmpty().WithMessage("Invalid ClientProspectID");
RuleForEach(x => x.Solicits).SetValidator(new SolicitValidator());
}
class SolicitValidator : AbstractValidator<Solicit>
{
public SolicitValidator()
{
RuleFor(x => x.StudyType).NotEqual(StudyType.Invalid).WithMessage("Invalid StudyType");
}
}
}
Just to highlight the question, in the case of failing the validation rule, is there a way that I can find which main or nested validator has failed.
var validationResult = validator.Validate(item);
if (!validationResult.IsValid)
{
invalidData.AddRange(validationResult.Errors.Select(q => new DataImportValidationResult
{
DataImportId = dataImportData.Id,
ClientProspectID = item.ClientProspectID,
ValidationResult = q.ErrorMessage,
AttemptedValue = q.AttemptedValue.ToString(),
Field = q.PropertyName,
Category = "", //Here I need a way to find which object has failed.
}));
}
If it is not possible to access the failed object, is there a way that we can set a property in the validations rule that can be accessible in the validationResult errors?

Custom impromptuobject for json.net deserialization

I was playing around with impromptu interface over a jobject and ran into the following issue
https://code.google.com/p/impromptu-interface/issues/detail?id=17
The issue is marked as 'Won't fix' and in the comments the author says that it could be fixed by implementing a custom impromptuobject.
Anyone have a sample of such an implementation? Or know another solution to this problem?
So the problem is that JArray has GetEnumerator() defined as interface-only, which makes the method no longer duck callable by the DLR. So below I've overriden the trygetmember to check if the result is a JArray's and convert it to a JEnumerable that implements GetEnumerator() in a dlr invokable way.
public class NonRecursiveJArrayConversionDictionary : ImpromptuDictionary{
public override bool TryGetMember(GetMemberBinder binder, out object result)
{
if(base.TryGetMember(binder, out result)){
if(result is JArray){
result = ((JArray)result).AsJEnumerable();
}
return true;
}
result = null;
return false;
}
}
However, this will only work for json structures that don't have arrays more then one property deep. You'll either have modify the above to recursively check anytime anything is returned maybe with a proxy, or modify the dictionary indexer's set to check and convert when deserialized instead.
Update: Json.net verion >= 5.0.4.16101 and ImpromptuInterface >= 6.1.4 will work out of the box.
void Main()
{
ICustomer customer = Impromptu.ActLike(JObject.Parse(#"
{
Id: 1,
Name:'Test',
Location:'Somewhere',
Employees: [
{ Id:1, EmployerId:39421, Name:'Joe' },
{ Id:2, EmployerId:39421, Name:'Jane' },
]
}
"));
foreach(var employee in customer.Employees){
employee.Id.Dump();
employee.Name.Dump();
}
}
public interface ICustomer
{
int Id { get; set; }
string Name { get; set; }
string Location { get; set; }
IList<IEmployee> Employees { get; }
}
public interface IEmployee
{
int Id { get; set; }
int EmployerId { get; set; }
string Name { get; set; }
}

Web API error failed to serialize the response body

Im fairly new to ASP.NET MCV 4 as well as Mongo DB and trying to build web API.
I thought I had finally got it right but when I start the app and enter: http://localhost:50491/api/document into my browser I get this error message
The 'ObjectContent`1' type failed to serialize the response body for content type 'application/xml; charset=utf-8'.
Here is my code
This is the Document Class
public class Document
{
[BsonId]
public ObjectId DocumentID { get; set; }
public IList<string> allDocs { get; set; }
}
This is where the Connection to the DB is made:
public class MongoConnectionHelper
{
public MongoCollection<BsonDocument> collection { get; private set; }
public MongoConnectionHelper()
{
string connectionString = "mongodb://127.0.0.1";
var server = MongoServer.Create(connectionString);
if (server.State == MongoServerState.Disconnected)
{
server.Connect();
}
var conn = server.GetDatabase("cord");
collection = conn.GetCollection("Mappings");
}
Here is the ApiController Class:
public class DocumentController : ApiController
{
public readonly MongoConnectionHelper docs;
public DocumentController()
{
docs = new MongoConnectionHelper();
}
public IList<BsonDocument> getAllDocs()
{
var alldocs = (docs.collection.FindAll().ToList());
return alldocs;
}
}
I read futher on and the error message suggested:
Type 'MongoDB.Bson.BsonObjectId' with data contract name 'BsonObjectId:http://schemas.datacontract.org/2004/07/MongoDB.Bson' is not expected. Consider using a DataContractResolver 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 DataContractSerializer.
That is all good and well but how do I do that?
Either a) don't serialize your document classes over Web API, and create some DTOs meant to be serialized, or b) use something else as ID.
If you want an easy auto-generated ID, and you're OK with the fact that it will consume slightly more space, you can resort to the following "hack":
public class Document
{
public Document()
{
Id = ObjectId.GenerateNewId().ToString();
}
public string Id { get; set; }
}
This way, you'll get MongoIDs, but they'll be stored as a string.
If you need Web API2 responce in XML format , you need to handle the default Id like below
eg: ObjectId("507f191e810c19729de860ea")
Either you need to remove the Id from serialization.
[DataContract]
public class Document
{
[BsonId]
public string Id { get; set; }
[DataMember]
public string Title { get; set; } //other properties you use
}
Or You can change the Type of ID with custom logic
public class GuidIdGenerator : IIdGenerator
{
public object GenerateId(object container, object document)
{
return Guid.NewGuid();
}
public bool IsEmpty(object id)
{
return string.IsNullOrEmpty(id.ToString());
}
}
public class Document
{
[BsonId(IdGenerator = typeof(GuidIdGenerator))]
public string Id { get; set; }
public string Title { get; set; } //other properties you use
}

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