Automapper error: Expressions mapping from methods not supported yet - automapper

Any idea what might cause the error "Expressions mapping from methods not supported yet." when trying to map two objects? I cannot find any reference to this error anywhere.
EDITED---
I have more information. I have a property in my DTO declared as:
public LookupItem RegionType { get; set; }
However, when I invoke the mapping, it generates the error, "Expressions mapping from methods not supported yet.".
However, if I change the string in the property name "Type" to anything else like "Typeo" or "ASDF", the mapping succeeds. In other words, if change the property name to "RegionTypeo". Am I breaking any convention rules here? There seems to be something wrong with including the string "Type" in my property name.
Below is the generated error:
Result Message:
Test method Rep.Tests.PlanServiceTest.GetBuildings threw exception:
System.NotImplementedException: Expressions mapping from methods not supported yet.
Result StackTrace:
at AutoMapper.PropertyMap.ResolveExpression(Type currentType, Expression instanceParameter)
at AutoMapper.QueryableExtensions.Extensions.CreateMemberBindings(IMappingEngine mappingEngine, Type typeIn, TypeMap typeMap, Expression instanceParameter)
at AutoMapper.QueryableExtensions.Extensions.CreateMapExpression(IMappingEngine mappingEngine, Type typeIn, Type typeOut, Expression instanceParameter)
at AutoMapper.QueryableExtensions.Extensions.CreateMapExpression(IMappingEngine mappingEngine, Type typeIn, Type typeOut)
at AutoMapper.QueryableExtensions.Extensions.<>c__DisplayClass12.<CreateMapExpression>b__0(TypePair tp)
at System.Collections.Concurrent.ConcurrentDictionary2.GetOrAdd(TKey key, Func2 valueFactory)
at AutoMapper.Internal.DictionaryFactoryOverride.ConcurrentDictionaryImpl2.GetOrAdd(TKey key, Func2 valueFactory)
at AutoMapper.QueryableExtensions.Extensions.CreateMapExpression[TSource,TDestination](IMappingEngine mappingEngine)
at AutoMapper.QueryableExtensions.ProjectionExpression1.ToTResult
at Rep.Services.PlanService.GetBuildings() in c:\Dev\REP\Rep\Services\PlanService.cs:line 369
at Rep.Tests.PlanServiceTest.GetBuildings() in c:\Dev\REP\Rep.Tests\PlanServiceTest.cs:line 50

Based on the source code, you can see that the exception is thrown when you try mapping functions on your objects:
public ExpressionResolutionResult ResolveExpression(Type currentType, Expression instanceParameter)
{
Expression currentChild = instanceParameter;
Type currentChildType = currentType;
foreach (var resolver in GetSourceValueResolvers())
{
var getter = resolver as IMemberGetter;
if (getter != null)
{
var memberInfo = getter.MemberInfo;
var propertyInfo = memberInfo as PropertyInfo;
if (propertyInfo != null)
{
currentChild = Expression.Property(currentChild, propertyInfo);
currentChildType = propertyInfo.PropertyType;
}
else
{
throw new NotImplementedException("Expressions mapping from methods not supported yet.");
}
}
else
{
var oldParameter = CustomExpression.Parameters.Single();
var newParameter = instanceParameter;
var converter = new ConversionVisitor(newParameter, oldParameter);
currentChild = converter.Visit(CustomExpression.Body);
currentChildType = currentChild.Type;
}
}
return new ExpressionResolutionResult(currentChild, currentChildType);
}
Based on OP clarification, I cannot reproduce the problem with the following:
public class Class1
{
public string StringType { get; set; }
public Func<Class1> FuncType { get; set; }
public Class1 Class1Type { get; set; }
}
public class Class2
{
public string StringType { get; set; }
public Func<Class1> FuncType { get; set; }
public Class1 Class1Type { get; set; }
}
/* ... */
AutoMapper.Mapper.CreateMap<Class1, Class2>();
var c1 = new Class1() { Class1Type = new Class1(), FuncType = () => new Class1(), StringType = "Class1" };
var c2 = AutoMapper.Mapper.Map<Class1, Class2>(new Class1());

Related

inherited class AutoMapper.AutoMapperMappingException

I am new at automapper and it is a very good stuff easy to use, but now I have a problem with it. Trying to convert my derived class to base and it gives me
AutoMapper.AutoMapperMappingException
Missing type map configuration or unsupported mapping.
Mapping types: ClientEventDb -> EventId
Database.ClientEventDb -> EventId
Destination path: ClientEvent
Source value:
Event:Login
Automapper wants to convert ClientEventDb to EventId? I don't understand why. EventId is an enum...
Please help me I have run out of ideas.
Here is the code which I run:
ClientEventDb[] edbl;
using (var context = new DbEntities())
{
edbl=context.Events.Take(1000).ToArray();
}
Mapper.CreateMap<ClientEventDb, ClientEvent>();
Console.WriteLine("hello");
return edbl.Select(edb => Mapper.Map<ClientEvent>(edb)).ToArray();
Here are my classes
[Table("events", Schema = "public")]
public class ClientEventDb : ClientEvent
{
public ClientEventDb(string userName, EventId happening, object userObject = null)
: base(userName, happening, userObject)
{
}
public ClientEventDb()
{
}
}
[ProtoContract]
[Table("events", Schema = "public")]
public class ClientEvent : ClientEventBase
{
[ProtoMember(1)]
[Column("username")]
public string UserName { get; private set; }
[ProtoMember(2)]
[Column("time")]
public DateTime DateTime { get; private set; }
[ProtoMember(3)]
[Key]
[Column("id")]
[DatabaseGenerated(DatabaseGeneratedOption.Identity)]
public string Id { get; private set; }
[ProtoMember(4)]
[Column("data")]
public byte[] UserObject { get; set; }
public ClientEvent(string userName,EventId happening, object userObject=null) : base(happening)
{
UserName = userName;
DateTime = DateTime.Now;
//UserObject = null;
if (userObject!=null) throw new NotImplementedException();
}
public ClientEvent()
{
}
protected ClientEvent Clone()
{
return (ClientEvent)MemberwiseClone();
}
}
[ProtoContract]
[ProtoInclude(10, typeof(ClientEvent))]
public class ClientEventBase
{
[Column("eventid")]
[ProtoMember(1)]
public int EventIdValue { get; set; } //must be public because of entity framework
[NotMapped]
public EventId EventId
{
get { return (EventId) EventIdValue; }
set { EventIdValue = (int) value; }
}
public ClientEventBase(EventId eventId)
{
EventId = eventId;
}
public ClientEventBase()
{
}
public override string ToString()
{
return String.Format("Event:{0}",EventId);
}
}
public enum EventId
{
Login = 1,
Logout,
ExitApplication,
}
UPDATE
bugfix: ClientEvent [Key] attribute moved to id property
Solution was this (thx to stuartd):
ClientEventDb[] edbl;
using (var context = new DbEntities())
{
edbl=context.Events.ToArray();
}
Mapper.CreateMap<ClientEventDb, ClientEvent>().ConstructUsing((ClientEventDb src) => new ClientEvent());
return edbl.Select(Mapper.Map<ClientEvent>).ToArray();
AutoMapper is confused as its made to map between similar properties in different classes, you are using it incorrectly - you just need to go from the derived class to the base which does not require AutoMapper. You could use this to do what you need....
ClientEventDb[] edbl;
using (var context = new DbEntities())
{
edbl=context.Events.Take(1000).ToArray();
}
return edbl.Cast<ClientEvent>().ToList();
I'd be looking at why you even feel you need a derived ClientEventDb though - understand we dont have the whole picture here but it seems to do nothing in addition to what the base class already does.
The issue is that ClientEvent has two constructors but you have not told AutoMapper which to use.
If you want it to use your constructor with parameters, change your mapping code to this and it will work:
Mapper.CreateMap<ClientEventDb, ClientEvent>()
.ConstructUsing(src => new ClientEvent(src.UserName, src.EventId));
Or to make AutoMapper use the default constructor:
Mapper.CreateMap<ClientEventDb, ClientEvent>()
.ConstructUsing((ClientEventDb src) => new ClientEvent());

C#, What's the proper syntax for calling an Expression<Func<T-in, T-out>> from within another lambda expression?

I'm working in Entity Framework 5 and having problems creating an expression to use inside a method.
I believe the problem is that normally I would call the expression in a lambda expression such as dbContext.Counties.Select(GetLargeCities()), but in the code I am working with, I am projecting the Counties entity into a view model called CountyWithCities. Where I would normally call the expression, I have a singleton c and don't know how to call the expression there.
The reason I want to accomplish this using an expression is because I want the GetCountiesWithCities method to hit the database once, with Entity Framework constructing a complex graph for all the objects in the result.
For some reason the code below is producing the error `The name 'GetLargeCities' does not exist in the current context."
public class CountyWithCities // this is a view model
{
public int CountyID { get; set; }
public string CountyName { get; set; }
public IEnumerable<City> Cities { get; set; }
}
public class City // this is an entity
{
public int CityID { get; set; }
public string CityName { get; set; }
public int Population { get; set; }
}
public IEnumerable<CountyWithCities> GetCountiesWithCities(int StateID)
{
return dbContext.States
.Where(s => s.StateID = StateID)
.Select(s => s.Counties)
.Select(c => new CountyWithCities
{
CountyID = c.CountyID,
CountyName = c.CountyName,
Cities = GetLargeCities(c) // How do I call the expression here?
});
}
public Expression<Func<County, IEnumerable<City>>> GetLargeCities = county =>
county.Cities.Where(city => city.Population > 50000);
Thanks!
I normally do this with an extension method.
public static IQueriable<City> LargeCities(this IQueriable<County> counties){
return counties
.SelectMany(county=>county.Cities.Where(c=>c.Population > 50000));
}
usage:
dbContext.Counties.LargeCities()
public IEnumerable<CountyWithCities> GetCountiesWithCities(int StateID)
{
return dbContext.States
.Where(s => s.StateID = StateID)
.Select(s => s.Counties)
.LargeCities()
.GroupBy(c=>c.County)
.Select(c => new CountyWithCities
{
CountyID = g.Key.CountyID,
CountyName = g.Key.CountyName,
Cities = g.AsQueriable() // i cant remember the exact syntax here but you need the list from the group
});
}

Automapper Guid to string mapping fails with NullReferenceException if used with Queryable Extensions

I'm having a problem with one of my mappings that I can't seem to resolve.
Here is the model:
public class Order
{
public virtual Guid Id { get; set; }
public virtual Client Client { get; set; }
}
public class Client
{
public virtual Guid Id { get; set; }
public virtual string Name { get; set; }
public virtual string Code { get; set; }
}
Here is the class I'm mapping to:
public class OrderDto
{
public string Id { get; set; }
public string ClientCode { get; set; }
}
Mapping and the test:
public class AutomapperTest
{
public AutomapperTest()
{
Mapper.Initialize(cfg => cfg.CreateMap<Order, OrderDto>()
.ForMember(dto => dto.Id, conf => conf.MapFrom(p => p.Id))
.ForMember(dto => dto.ClientCode, conf => conf.MapFrom(p => p.Client.Code)));
Mapper.AssertConfigurationIsValid();
}
[Fact]
public void MappingTest()
{
Client client = new Client { Id = Guid.NewGuid(), Code = "CTS" };
Order order = new Order { Id = Guid.NewGuid(), Client = client };
List<Order> orders = new List<Order> { order };
List<OrderDto> list = orders.AsQueryable().Project().To<OrderDto>().ToList();
}
}
Test fails with a NullReferenceException on an attempt to project the list of OrderDto objects. Here is the exception, which comes from Automapper:
System.NullReferenceException
Object reference not set to an instance of an object.
at AutoMapper.QueryableExtensions.Extensions.CreateMapExpression(IMappingEngine mappingEngine, Type typeIn, Type typeOut) in QueryableExtensions.cs: line 50
at AutoMapper.QueryableExtensions.Extensions.CreateMapExpression(IMappingEngine mappingEngine, Type typeIn, Type typeOut) in QueryableExtensions.cs: line 136
at AutoMapper.QueryableExtensions.Extensions.<>c__DisplayClass1`2.<CreateMapExpression>b__0(TypePair tp) in QueryableExtensions.cs: line 24
at System.Collections.Concurrent.ConcurrentDictionary`2.GetOrAdd(TKey key, Func`2 valueFactory)
at AutoMapper.Internal.DictionaryFactoryOverride.ConcurrentDictionaryImpl`2.GetOrAdd(TKey key, Func`2 valueFactory) in ConcurrentDictionaryFactory.cs: line 37
at AutoMapper.QueryableExtensions.Extensions.CreateMapExpression(IMappingEngine mappingEngine) in QueryableExtensions.cs: line 21
at AutoMapper.QueryableExtensions.ProjectionExpression`1.To() in QueryableExtensions.cs: line 251
at AutoMapperIssue.AutomapperTest.MappingTest() in Class1.cs: line 47
Mapping works just fine if Queryable Extension is not used:
List<OrderDto> dtos = Mapper.Map<List<Order>, List<OrderDto>>(orders);
Am I missing something?
Just an update:
I'm using it with NHibernate, getting identical exception.
var fromDb = Session.Query<Order>().Project().To<OrderDto>().ToList();
Seems like it chokes on Guid to string conversion. If i comment the Id field out, it works fine for both NHibernate and collection.AsQueryable().
private static LambdaExpression CreateMapExpression(IMappingEngine mappingEngine, Type typeIn, Type typeOut)
{
var typeMap = mappingEngine.ConfigurationProvider.FindTypeMapFor(typeIn, typeOut);
...
foreach (var propertyMap in typeMap.GetPropertyMaps().Where(pm => pm.CanResolveValue()))
{
...
}
}
it fails on foreach since typeMap is null. typeIn = System.Guid typeOut = System.String
In version 3.1.1 need to reference both dlls:
AutoMapper and AitoMapper.Net4
In version 3.2.1 still an issue
It appears to be a legit limitation. Here is the author's explanation

Using a custom type discriminator to tell JSON.net which type of a class hierarchy to deserialize

Suppose I have the following class hierarchy:
public abstract class Organization
{
/* properties related to all organizations */
}
public sealed class Company : Organization
{
/* properties related to companies */
}
public sealed class NonProfitOrganization : Organization
{
/* properties related to non profit organizations */
}
Is it possible to have json.net use property (say "type" or "discriminator") to determine which type the object when it deserializes the organization? For example, the following should deserialize an instance of Company.
{
"type": "company"
/* other properties related to companies */
}
And the following should deserialize an instance of NonProfitOrganization.
{
"type": "non-profit"
/* other properties related to non profit */
}
When I call the following:
Organization organization = JsonConvert.DeserializeObject<Organization>(payload);
where payload is the above JSON snippets. I had a look at setting the "TypeNameHandling" on properties or classes but it serializes the whole .NET type, which isn't "portable" between the client and server when the classes are defined in different namespaces and assemblies.
I'd rather define the type is a neutral manner which clients written in any language can use to determine the actual type of the object type being serialized.
In case you are still looking, here is an example: http://james.newtonking.com/archive/2011/11/19/json-net-4-0-release-4-bug-fixes.aspx
This will allow you to create a table based mapping:
public class TypeNameSerializationBinder : SerializationBinder
{
public TypeNameSerializationBinder(Dictionary<Type, string> typeNames = null)
{
if (typeNames != null)
{
foreach (var typeName in typeNames)
{
Map(typeName.Key, typeName.Value);
}
}
}
readonly Dictionary<Type, string> typeToName = new Dictionary<Type, string>();
readonly Dictionary<string, Type> nameToType = new Dictionary<string, Type>(StringComparer.OrdinalIgnoreCase);
public void Map(Type type, string name)
{
this.typeToName.Add(type, name);
this.nameToType.Add(name, type);
}
public override void BindToName(Type serializedType, out string assemblyName, out string typeName)
{
var name = typeToName.Get(serializedType);
if (name != null)
{
assemblyName = null;
typeName = name;
}
else
{
assemblyName = serializedType.Assembly.FullName;
typeName = serializedType.FullName;
}
}
public override Type BindToType(string assemblyName, string typeName)
{
if (assemblyName == null)
{
var type = this.nameToType.Get(typeName);
if (type != null)
{
return type;
}
}
return Type.GetType(string.Format("{0}, {1}", typeName, assemblyName), true);
}
}
The code has a slight defect in that if a type name mapping is attempted where the type is unique but the name is already used, the Map method will throw an exception after the type-to-name mapping is already added leaving the table in an inconsistent state.
To take eulerfx's answer further; I wanted to apply DisplayName attribute to a class and have that automatically become the type name used; to that end:
public class DisplayNameSerializationBinder : DefaultSerializationBinder
{
private Dictionary<string, Type> _nameToType;
private Dictionary<Type, string> _typeToName;
public DisplayNameSerializationBinder()
{
var customDisplayNameTypes =
this.GetType()
.Assembly
//concat with references if desired
.GetTypes()
.Where(x => x
.GetCustomAttributes(false)
.Any(y => y is DisplayNameAttribute));
_nameToType = customDisplayNameTypes.ToDictionary(
t => t.GetCustomAttributes(false).OfType<DisplayNameAttribute>().First().DisplayName,
t => t);
_typeToName = _nameToType.ToDictionary(
t => t.Value,
t => t.Key);
}
public override void BindToName(Type serializedType, out string assemblyName, out string typeName)
{
if (false == _typeToName.ContainsKey(serializedType))
{
base.BindToName(serializedType, out assemblyName, out typeName);
return;
}
var name = _typeToName[serializedType];
assemblyName = null;
typeName = name;
}
public override Type BindToType(string assemblyName, string typeName)
{
if (_nameToType.ContainsKey(typeName))
return _nameToType[typeName];
return base.BindToType(assemblyName, typeName);
}
}
and usage example:
public class Parameter
{
public string Name { get; set; }
};
[DisplayName("bool")]
public class BooleanParameter : Parameter
{
}
[DisplayName("string")]
public class StringParameter : Parameter
{
public int MinLength { get; set; }
public int MaxLength { get; set; }
}
[DisplayName("number")]
public class NumberParameter : Parameter
{
public double Min { get; set; }
public double Max { get; set; }
public string Unit { get; set; }
}
[DisplayName("enum")]
public class EnumParameter : Parameter
{
public string[] Values { get; set; }
}
internal class Program
{
private static void Main(string[] args)
{
var parameters = new Parameter[]
{
new BooleanParameter() {Name = "alive"},
new StringParameter() {Name = "name", MinLength = 0, MaxLength = 10},
new NumberParameter() {Name = "age", Min = 0, Max = 120},
new EnumParameter() {Name = "status", Values = new[] {"Single", "Married"}}
};
JsonConvert.DefaultSettings = () => new JsonSerializerSettings
{
Binder = new DisplayNameSerializationBinder(),
TypeNameHandling = TypeNameHandling.Auto,
NullValueHandling = NullValueHandling.Ignore,
DefaultValueHandling = DefaultValueHandling.Ignore,
Formatting = Formatting.Indented,
ContractResolver = new CamelCasePropertyNamesContractResolver()
};
var json = JsonConvert.SerializeObject(parameters);
var loadedParams = JsonConvert.DeserializeObject<Parameter[]>(json);
Console.WriteLine(JsonConvert.SerializeObject(loadedParams));
}
}
output:
[
{
"$type": "bool",
"name": "alive"
},
{
"$type": "string",
"maxLength": 10,
"name": "name"
},
{
"$type": "number",
"max": 120.0,
"name": "age"
},
{
"$type": "enum",
"values": [
"Single",
"Married"
],
"name": "status"
}
]
I've written purely declarative solution with ability to specify custom discriminator field, and provide scoped name handling per base class (as opposed to usecure global JsonSerializationSettings, especially on different Web-Api when we do not have ability to specify custom JsonSerializationSettings).
using System;
using Newtonsoft.Json;
using Newtonsoft.Json.Linq;
using System.Reflection;
using System.Linq;
using System.Collections.Generic;
// Discriminated Json Converter (JsonSubtypes) implementation for .NET
//
// MIT License
//
// Copyright (c) 2016 Anatoly Ressin
// Permission is hereby granted, free of charge, to any person obtaining a
// copy of this software and associated documentation files (the "Software"),
// to deal in the Software without restriction, including without limitation
// the rights to use, copy, modify, merge, publish, distribute, sublicense,
// and/or sell copies of the Software, and to permit persons to whom the
// Software is furnished to do so, subject to the following conditions:
//
// The above copyright notice and this permission notice shall be included in
// all copies or substantial portions of the Software.
//
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
// OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
// FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
// DEALINGS IN THE SOFTWARE.
////////////////////// USAGE ////////////////////////////////////////////////////////////////////////////////
[JsonConverter(typeof(JsonSubtypes))] // Discriminated base class SHOULD NOT be abstract
public class ShapeBase {
[JsonTag, JsonProperty("#type")] // it SHOULD contain a property marked with [JsonTag]
public string Type {get;set;} // only one [JsonTag] annotation allowed per discriminated class
// it COULD contain other properties, however this is NOT RECOMMENDED
// Rationale: instances of this class will be created at deserialization
// only for tag sniffing, and then thrown away.
}
public abstract class Shape: ShapeBase { // If you want abstract parent - extend the root
public abstract double GetArea(); // with needed abstract stuff, then use this class everywhere (see DEMO below)
}
[JsonSubtype("circle")] // Every final class-case SHOULD be marked with [JsonSubtype(tagValue)]
public class Circle: Shape { // Two disctinct variant classes MUST have distinct tagValues
[JsonProperty("super-radius")] // You CAN use any Json-related annotation as well
public double Radius { get; set; }
public override double GetArea() {
return Radius * Radius * Math.PI;
}
}
[JsonSubtype("rectangle")]
public class Rectangle: Shape {
public double Height { get; set; }
public double Width { get; set; }
public override double GetArea() {
return Width * Height;
}
}
[JsonSubtype("group")]
public class Group: Shape {
[JsonProperty("shapes")]
public List<Shape> Items { get; set; }
public override double GetArea() {
return Items.Select(item => item.GetArea()).Sum();
}
}
// Every final class-case SHOULD be registered with JsonSubtypes.register(typeof(YourConcreteClass))
// either manually or with auto-register capability:
// You can auto-register all classes marked with [JsonSubtype(tag)] in given Assembly
// using JsonSubtypes.autoRegister(yourAssembly)
////////////////// DEMO /////////////////////////////////////////////////////////////////////////////////
public class Program
{
public static void Main()
{
JsonSubtypes.autoRegister(Assembly.GetExecutingAssembly());
Shape original = new Group() {
Items = new List<Shape> {
new Circle() { Radius = 5 },
new Rectangle() { Height = 10, Width = 20 }
}
};
string str = JsonConvert.SerializeObject(original);
Console.WriteLine(str);
var copy = JsonConvert.DeserializeObject(str,typeof(Shape)) as Shape;
// Note: we can deserialize object using any class from the hierarchy.
// Under the hood, anyway, it will be deserialized using the top-most
// base class annotated with [JsonConverter(typeof(JsonSubtypes))].
// Thus, only soft-casts ("as"-style) are safe here.
Console.WriteLine("original.area = {0}, copy.area = {1}", original.GetArea(), copy.GetArea());
}
}
//////////////////////// IMPLEMENTATION //////////////////////////////////////////////////////////////////
public class JsonSubtypeClashException: Exception {
public string TagValue { get; private set;}
public Type RootType { get; private set; }
public Type OldType { get; private set; }
public Type NewType { get; private set; }
public JsonSubtypeClashException(Type rootType, string tagValue, Type oldType, Type newType): base(
String.Format(
"JsonSubtype Clash for {0}[tag={1}]: oldType = {2}, newType = {3}",
rootType.FullName,
tagValue,
oldType.FullName,
newType.FullName
)
) {
TagValue = tagValue;
RootType = rootType;
OldType = oldType;
NewType = newType;
}
}
public class JsonSubtypeNoRootException: Exception {
public Type SubType { get; private set; }
public JsonSubtypeNoRootException(Type subType): base(
String.Format(
"{0} should be inherited from the class with the [JsonConverter(typeof(JsonSubtypes))] attribute",
subType.FullName
)
) {
SubType = subType;
}
}
public class JsonSubtypeNoTagException: Exception {
public Type SubType { get; private set; }
public JsonSubtypeNoTagException(Type subType): base(
String.Format(
#"{0} should have [JsonSubtype(""..."")] attribute",
subType.FullName
)
) {
SubType = subType;
}
}
public class JsonSubtypeNotRegisteredException: Exception {
public Type Root { get; private set; }
public string TagValue { get; private set; }
public JsonSubtypeNotRegisteredException(Type root, string tagValue): base(
String.Format(
#"Unknown tag={1} for class {0}",
root.FullName,
tagValue
)
) {
Root = root;
TagValue = tagValue;
}
}
[AttributeUsage(AttributeTargets.Class)]
public class JsonSubtypeAttribute: Attribute {
private string tagValue;
public JsonSubtypeAttribute(string tagValue) {
this.tagValue = tagValue;
}
public string TagValue {
get {
return tagValue;
}
}
}
public static class JsonSubtypesExtension {
public static bool TryGetAttribute<T>(this Type t, out T attribute) where T: Attribute {
attribute = t.GetCustomAttributes(typeof(T), false).Cast<T>().FirstOrDefault();
return attribute != null;
}
private static Dictionary<Type, PropertyInfo> tagProperties = new Dictionary<Type, PropertyInfo>();
public static bool TryGetTagProperty(this Type t, out PropertyInfo tagProperty) {
if (!tagProperties.TryGetValue(t, out tagProperty)) {
JsonConverterAttribute conv;
if (t.TryGetAttribute(out conv) && conv.ConverterType == typeof(JsonSubtypes)) {
var props = (from prop in t.GetProperties() where prop.GetCustomAttribute(typeof(JsonTagAttribute)) != null select prop).ToArray();
if (props.Length == 0) throw new Exception("No tag");
if (props.Length > 1) throw new Exception("Multiple tags");
tagProperty = props[0];
} else {
tagProperty = null;
}
tagProperties[t] = tagProperty;
}
return tagProperty != null;
}
public static bool TryGetTagValue(this Type t, out string tagValue) {
JsonSubtypeAttribute subtype;
if (t.TryGetAttribute(out subtype)) {
tagValue = subtype.TagValue;
return true;
} else {
tagValue = null;
return false;
}
}
public static bool TryGetJsonRoot(this Type t, out Type root, out PropertyInfo tagProperty) {
root = t;
do {
if (root.TryGetTagProperty(out tagProperty)) {
return true;
}
root = root.BaseType;
} while (t != null);
return false;
}
}
public class JsonTagAttribute: Attribute {
}
public class JsonTagInfo {
public PropertyInfo Property { get; set; }
public string Value { get; set; }
}
public class JsonRootInfo {
public PropertyInfo Property { get; set; }
public Type Root { get; set; }
}
public abstract class DefaultJsonConverter: JsonConverter {
[ThreadStatic]
private static bool silentWrite;
[ThreadStatic]
private static bool silentRead;
public sealed override bool CanWrite {
get {
var canWrite = !silentWrite;
silentWrite = false;
return canWrite;
}
}
public sealed override bool CanRead {
get {
var canRead = !silentRead;
silentRead = false;
return canRead;
}
}
protected void _WriteJson(JsonWriter writer, Object value, JsonSerializer serializer) {
silentWrite = true;
serializer.Serialize(writer, value);
}
protected Object _ReadJson(JsonReader reader, Type objectType, Object existingValue, JsonSerializer serializer) {
silentRead = true;
return serializer.Deserialize(reader, objectType);
}
}
public class JsonSubtypes: DefaultJsonConverter {
private static Dictionary<Type, Dictionary<string, Type>> implementations = new Dictionary<Type, Dictionary<string, Type>>();
private static Dictionary<Type, JsonTagInfo> tags = new Dictionary<Type, JsonTagInfo>();
private static Dictionary<Type, JsonRootInfo> roots = new Dictionary<Type, JsonRootInfo>();
public static void register(Type newType) {
PropertyInfo tagProperty;
Type root;
if (newType.TryGetJsonRoot(out root, out tagProperty)) {
for(var t = newType; t != root; t = t.BaseType) {
roots[t] = new JsonRootInfo() {
Property = tagProperty,
Root = root
};
}
roots[root] = new JsonRootInfo() {
Property = tagProperty,
Root = root
};
Dictionary<string, Type> implementationMap;
if (!implementations.TryGetValue(root, out implementationMap)) {
implementationMap = new Dictionary<string, Type>();
implementations[root] = implementationMap;
}
JsonSubtypeAttribute attr;
if (!newType.TryGetAttribute(out attr)) {
throw new JsonSubtypeNoTagException(newType);
}
var tagValue = attr.TagValue;
Type oldType;
if (implementationMap.TryGetValue(tagValue, out oldType)) {
throw new JsonSubtypeClashException(root, tagValue, oldType, newType);
}
implementationMap[tagValue] = newType;
tags[newType] = new JsonTagInfo() {
Property = tagProperty,
Value = tagValue
};
} else {
throw new JsonSubtypeNoRootException(newType);
}
}
public static void autoRegister(Assembly assembly) {
foreach(var type in assembly.GetTypes().Where(type => type.GetCustomAttribute<JsonSubtypeAttribute>() != null)) {
register(type);
}
}
public override bool CanConvert(Type t) {
return true;
}
public static T EnsureTag<T>(T value) {
JsonTagInfo tagInfo;
if (tags.TryGetValue(value.GetType(), out tagInfo)) {
tagInfo.Property.SetValue(value, tagInfo.Value);
}
return value;
}
public override void WriteJson(JsonWriter writer, Object value, JsonSerializer serializer) {
_WriteJson(writer, EnsureTag(value), serializer);
}
public override Object ReadJson(JsonReader reader, Type objectType, Object existingValue, JsonSerializer serializer) {
JsonTagInfo tagInfo;
if (tags.TryGetValue(objectType, out tagInfo)) {
return _ReadJson(reader, objectType, existingValue, serializer);
} else {
JsonRootInfo rootInfo;
if (roots.TryGetValue(objectType, out rootInfo)) {
JToken t = JToken.ReadFrom(reader);
var stub = _ReadJson(t.CreateReader(), rootInfo.Root, existingValue, serializer);
var tagValue = rootInfo.Property.GetValue(stub) as string;
var implementationMap = implementations[rootInfo.Root];
Type implementation;
if (implementationMap.TryGetValue(tagValue, out implementation)) {
return ReadJson(t.CreateReader(), implementation, null, serializer);
} else {
throw new JsonSubtypeNotRegisteredException(rootInfo.Root, tagValue);
}
} else {
return _ReadJson(reader, objectType, existingValue, serializer);
}
}
}
public static T Deserialize<T>(string s) where T: class {
return JsonConvert.DeserializeObject(s, typeof(T)) as T;
}
public static string Serialize<T>(T value) where T: class {
return JsonConvert.SerializeObject(value);
}
}
output:
{"shapes":[{"super-radius":5.0,"#type":"circle"},{"Height":10.0,"Width":20.0,"#type":"rectangle"}],"#type":"group"}
original.area = 278.539816339745, copy.area = 278.539816339745
You can grab it here:
https://dotnetfiddle.net/ELcvnk
With another JsonSubtypes converter implementation.
Usage:
[JsonConverter(typeof(JsonSubtypes), "Sound")]
[JsonSubtypes.KnownSubType(typeof(Dog), "Bark")]
[JsonSubtypes.KnownSubType(typeof(Cat), "Meow")]
public class Animal
{
public virtual string Sound { get; }
public string Color { get; set; }
}
public class Dog : Animal
{
public override string Sound { get; } = "Bark";
public string Breed { get; set; }
}
public class Cat : Animal
{
public override string Sound { get; } = "Meow";
public bool Declawed { get; set; }
}
[TestMethod]
public void Demo()
{
var input = #"{""Sound"":""Bark"",""Breed"":""Jack Russell Terrier""}"
var animal = JsonConvert.DeserializeObject<Animal>(input);
Assert.AreEqual("Jack Russell Terrier", (animal as Dog)?.Breed);
}
the converter implementation can be directly downloaded from the repository: JsonSubtypes.cs and is also availble as a nuget package
Use this JsonKnownTypes, it's very similar way to use, add couple of attribute:
[JsonConverter(typeof(JsonKnownTypeConverter<Organization>))]
[JsonDiscriminator(Name = "discriminator")]
[JsonKnownType(typeof(Company), "company")]
[JsonKnownType(typeof(NonProfitOrganization), "non-profit")]
public abstract class Organization
{
/* properties related to all organizations */
}
public sealed class Company : Organization
{
/* properties related to companies */
}
public sealed class NonProfitOrganization : Organization
{
/* properties related to non profit organizations */
}
And serialize:
var json = JsonConvert.SerializeObject(youObject)
Output json:
{..., "discriminator":"non-profit"} //if object was NonProfitOrganization
Deserialization:
var organization = JsonConvert.DeserializeObject<Organization>(payload);

how to confige an abstract class with structure map

is there any problem with this kinda registration via structure map??
static public class ContainerBootstrapper
{
static public void BootstrapDefaultContainer(bool test = false)
{
StructureMap.ObjectFactory.Initialize(x =>
{
x.Scan(p =>
{
p.AssemblyContainingType<IPropertyType>();
p.AddAllTypesOf<IPropertyType>();
// p.AddAllTypesOf<IPropertyType>().NameBy(c => c.Name);
});
});
}
public interface IPropertyType : IIdentityObject, IPriority
{
string PropertyName { get; set; }
ObjectType ObjectType { get; }
string DisplayName { get; set; }
IEntityType EntityType { get; set; }
IList<IPropertyRuleObject> RuleObjects { get; set; }
void AddRuleObject(IPropertyRuleObject ruleObject);
}
public abstract class PropertyTypeBase : PersistentObject, IPropertyType
{
public PropertyTypeBase()
{
}
public PropertyTypeBase(string propertyName, string displayName)
{
PropertyName = propertyName;
DisplayName = displayName;
}
....
}
public class StringType : PropertyTypeBase
{
private ObjectType _objectType;
public StringType()
{
_objectType = new ObjectType(typeof(string));
}
public StringType(string propertyName, string displayName)
: base()
{
PropertyName = propertyName;
DisplayName = displayName;
}
public override ObjectType ObjectType
{
get { return _objectType; }
}
}
when ContainerBootstrapper.BootstrapDefaultContainer(); execute I see this line of error:
StructureMap Exception Code: 200
Could not find an Instance named "StringType" for PluginType Azarakhsh.Domain.Core.AdaptiveObjectModel.Interface.IPropertyType
the calling code:
public IPropertyType GetPropertyType(IIdentityObject identityObject, string name)
{
string[] Properties = name.Split('.');
object Result = identityObject;
foreach (var Property in Properties)
Result = Result.GetType().GetProperty(Property).PropertyType.Name;
IPropertyType propertyType = StructureMap.ObjectFactory.GetNamedInstance<IPropertyType> (Result + "Type");
if (propertyType==null)
throw new Exception("Property type not found");
return propertyType;
}
what is the problem?
You are trying to get a named instance, but from what I can see of the code you have provided, you dont name your instances. The line of code that name your instances is commented out.
But even if you would just use the ObjectFactory.GetInstance<IPropertyType>(); here, you would have got an error because structuremap dont know what constructor to use. There are several solutions to theis problem.
Change your design so you only have one constructor
Mark your default constructor with the [DefaultConstructor] attribute, then it will work.
You can register it with objectFactory manually with something like this:
x.For().Use().Ctor("propertyName").Is("someValue").Ctor("displayName").Is("someValue");
You can write a custom registrationconvention as described here

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