Related
I recently started learning Unit Testing and now have the requirement write unit tests using Xunit and Moq for dot net core application.
I can write some very basic but when it comes to write them for complex classes , I am kind of stuck.
Below is the class I will be writing tests for.
public class AgeCategoryRequestHandler : IInventoryRequestHandler<InventoryRequest, HandlerResult>
{
private readonly IRepositoryResolver _repositoryResolver;
Hotels.HBSI.Logging.ILogger logger;
public AgeCategoryRequestHandler(IRepositoryResolver repositoryResolver, Hotels.HBSI.Logging.ILogger iLogger)
{
_repositoryResolver = repositoryResolver;
logger = iLogger;
}
public async Task<HandlerResult> Run(InventoryRequest inventoryRequest)
{
var result = await ProcessRequest(inventoryRequest);
return CreateResponse(inventoryRequest, result);
}
private async Task<int> ProcessRequest(InventoryRequest inventoryRequest)
{
logger.Info("AgeCategory requesthandler processrequest start");
var repository = _repositoryResolver.ResolveEstabAgeCategory();
if (repository is not null)
{
return await repository.InsertUpdateEstabAgeCategoryDetail(inventoryRequest.EstabAgeCategories)
.ConfigureAwait(false);
}
logger.Info("AgeCategory requesthandler processrequest complete");
return InernalError.reponotfound;
}
public HandlerResult CreateResponse(InventoryRequest inventoryRequest, int resultCount)
{
var requestCount = inventoryRequest.EstabAgeCategories.Count;
var handlerResult = new HandlerResult() { Id = RequestHandlerEnum.AgeCategrory.ToInt() };
if (requestCount > 0 && resultCount < requestCount)
{
handlerResult.IsSuccess = false;
handlerResult.ErrorCode = OTAErrorType.InvalidAgeCategory.ToInt();
}
else if (requestCount > 0 || requestCount == resultCount)
{
handlerResult.IsSuccess = true;
handlerResult.ErrorCode = 0;
}
return handlerResult;
}
}
Just to start , IRepositoryResolver and ILogger are in the constructor so I have created mock for these but unable to go beyond that as I am still in initial phase of learning.
Could someone explain me the steps/approach to accomplish this?.
Edit : What I have done so far is below ( can't figure out what are the things to be done and where to start or write )
Edit 2 : Did some more modifications to my test code , can someone comment if I am in right direction ? what else can I test ?
public class AgeCategoryRequestHandlerTest
{
private AgeCategoryRequestHandler _ageCategoryRequestHandler;
private readonly Mock<AgeCategoryRequestHandler> _ageCategory = new Mock<AgeCategoryRequestHandler>();
private readonly Mock<Hotels.HBSI.Logging.ILogger> _mockLogger = new Mock<Hotels.HBSI.Logging.ILogger>();
private readonly Mock<IRepositoryResolver> _mockRepositoryResolver = new Mock<IRepositoryResolver>();
public AgeCategoryRequestHandlerTest()
{
_ageCategoryRequestHandler = new AgeCategoryRequestHandler(_mockRepositoryResolver.Object, _mockLogger.Object);
}
[Fact]
public async void Testtt()
{
var fixture = new Fixture();
var inventory = fixture.Create<InventoryRequest>();
var hndlr = fixture.Create<HandlerResult>();
hndlr.ErrorCode = 0;
int resultCount = 3;
await _ageCategoryRequestHandler.Run(inventory);
HandlerResult response = _ageCategoryRequestHandler.CreateResponse(inventory, resultCount);
Assert.Equal(hndlr.ErrorCode, response.ErrorCode);
}
Tried running Chris B suggested code , was getting type conversion error EstabAgeCategories = new List<int>
Now I have used fixture for creating automatic objects and did some assert values. Below is the code sample
var fixture = new Fixture();
var inventoryRequest = fixture.Create<InventoryRequest>();
_mockRepository
.Setup(x => x.InsertUpdateEstabAgeCategoryDetail(inventoryRequest.EstabAgeCategories))
.ReturnsAsync(6);
_mockRepositoryResolver
.Setup(x => x.ResolveEstabAgeCategory())
.Returns(_mockRepository.Object);
// act
var result = await _ageCategoryRequestHandler.Run(inventoryRequest);
// assert
_mockRepository
.Verify(x => x.InsertUpdateEstabAgeCategoryDetail(inventoryRequest.EstabAgeCategories), Times.Once);
Assert.True(result.Id == 6);
Assert.True(result.ErrorCode == 0);
Assert.True(result.IsSuccess);
From the unit test code you've posted, it looks like you are getting confused on what to test.
Look at your class and identify your "public" interface i.e. what methods can be called from other parts of your code. You should really only test public methods. Private methods are usually tested via public methods.
Looking at AgeCategoryRequestHandler, you have two public methods - Run and CreateResponse. I would question whether CreateResponse needs to be public but we'll leave it for now. For each of these methods, you want to be asserting that the returned value is what you expect given the input value.
private AgeCategoryRequestHandler _ageCategoryRequestHandler;
// Not needed
private readonly Mock<AgeCategoryRequestHandler> _ageCategory = new Mock<AgeCategoryRequestHandler>();
private readonly Mock<Hotels.HBSI.Logging.ILogger> _mockLogger = new Mock<Hotels.HBSI.Logging.ILogger>();
private readonly Mock<IRepositoryResolver> _mockRepositoryResolver = new Mock<IRepositoryResolver>();
public AgeCategoryRequestHandlerTest()
{
_ageCategoryRequestHandler = new AgeCategoryRequestHandler(_mockRepositoryResolver.Object, _mockLogger.Object);
}
The set up of the unit test is going the right way - you have created mocks for your dependencies but I see you have created a mock for the class you are trying to test - this is not needed and can be removed. You want to be testing the actual class itself which you are initializing in the constructor.
public async Task<HandlerResult> Run(InventoryRequest inventoryRequest)
{
var result = await ProcessRequest(inventoryRequest);
return CreateResponse(inventoryRequest, result);
}
private async Task<int> ProcessRequest(InventoryRequest inventoryRequest)
{
_logger.LogInformation("AgeCategory requesthandler processrequest start");
var repository = _repositoryResolver.ResolveEstabAgeCategory();
if (repository != null)
{
return await repository.InsertUpdateEstabAgeCategoryDetail(inventoryRequest.EstabAgeCategories).ConfigureAwait(false);
}
_logger.LogInformation("AgeCategory requesthandler processrequest complete");
return 0;
}
We can test the public Run method by looking at the method and seeing what it is going to do when executed. Firstly, it's going to call a private method ProcessRequest. Inside ProcessRequest, the IRepositoryResolver dependency is going to be used. This means we need to "set up" this dependency in our unit test to satisfy the if (repository != null) condition.
I assume the IRepositoryResolver returns another interface (?) - something like:
public interface IRepository
{
Task<int> InsertUpdateEstabAgeCategoryDetail(List<int> x);
}
So in your unit test, you need to create a mock for the repository being returned from IRepositoryResolver:
private readonly Mock<IRepository> _mockRepository = new Mock<IRepository>();
Then, you need to set up the mock IRepositoryResolver to return the mock repository above:
_mockRepositoryResolver
.Setup(x => x.ResolveEstabAgeCategory())
.Returns(_mockRepository.Object);
This is to satisfy the if (repository != null) condition.
_mockRepository
.Setup(x => x.InsertUpdateEstabAgeCategoryDetail(inventoryRequest.EstabAgeCategories))
.ReturnsAsync(6);
Next, you need to set up the InsertUpdateEstabAgeCategoryDetail() method on the mock repository to return a value. This value is being returned by ProcessRequest() and then used to call CreateResponse(inventoryRequest, result) as the result parameter.
if (requestCount > 0 && resultCount < requestCount)
{
handlerResult.IsSuccess = false;
handlerResult.ErrorCode = (int)OTAErrorType.InvalidAgeCategory;
}
else if (requestCount > 0 || requestCount == resultCount)
{
handlerResult.IsSuccess = true;
handlerResult.ErrorCode = 0;
}
Now you can look at the CreateResponse method and by setting different values for inventoryRequest.EstabAgeCategories and setting up the mock _mockRepository.Setup(x => x.InsertUpdateEstabAgeCategoryDetail(inventoryRequest.EstabAgeCategories)).ReturnsAsync(6); to return different values, you can satisfy the different paths through the if statement.
CreateResponse is returning an instance of HandlerResult which in turn is being returned by Task<HandlerResult> Run. This is the returned object you want to make assertions on.
One of the unit test cases might look like this (I have not tested it myself):
[Fact]
public async Task GivenInventoryRequest_WhenRun_ThenHandlerResultReturned()
{
// arrange
var inventoryRequest = new InventoryRequest
{
EstabAgeCategories = new List<int>
{
1, 2, 3, 4, 5
}
};
_mockRepository
.Setup(x => x.InsertUpdateEstabAgeCategoryDetail(inventoryRequest.EstabAgeCategories))
.ReturnsAsync(6);
_mockRepositoryResolver
.Setup(x => x.ResolveEstabAgeCategory())
.Returns(_mockRepository.Object);
// act
var result = await _ageCategoryRequestHandler.Run(inventoryRequest);
// assert
_mockRepository
.Verify(x => x.InsertUpdateEstabAgeCategoryDetail(inventoryRequest.EstabAgeCategories), Times.Once);
Assert.True(result.Id == 0);
Assert.True(result.ErrorCode == 0);
Assert.False(result.IsSuccess);
}
I have a REST API. I need to create presentation (DTO) object, but the construction of this object depends on request - it differs in 15%.
I wonder what pattern should I use.
My case:
//presentation-DTO
class Item {
private $name;
private $price;
private $tags;
private $liked; //is Liked by logged user
...
public function __construct(Item $item, bool $liked, ...)
{
$this->name = $item->getName();
$this->price = $item->getPrice();
$this->tags = $item->getTags();
$this->liked = $liked;
...
}
}
When user is not logged in - I don't need $liked
When showing list of items - I don't need $tags
And there are more attributes that works as above.
My first idea was to use Builder principle.
$itemBuilder = new ItemBuilder();
$itemBuilder->setItem($item);
...
if($user) {
$itemBuilder->setUserLiked($userLiked);
...
}
return $itemBuilder->build();
It solves my problem with too many parameters in constructor.
But still, I also don't need all parameters to be constructed - eg. I don't need tags (on lists). As I use lazy load, I don't want my dto constructor to call them.
So I thought, maybe Factory.. but then my problem with too many (and optional) parameters is returning.
How will you solve this?
Sorry I don't have required points to make a comment hence an answer.
What are you trying to do with the Item class. Your class is Item and first parameter is also of type Item. I cannot visualizes how its going to work.
I will prefer to keep business login to set proper properties in a separate class:
/**
* A class for business logic to set the proper properties
*/
class ItemProperties {
private $item;
public $isLogin = false;
public $showList = false;
.....
public function __construct(Item &$item) {
// set all properties;
}
public function getProperties() {
$retVal = [];
if($this->isLogin == true) {
$retVal['liked'] = true;
}
if($this->showList == true) {
$retVal['tags'] = $this->item->getTags();
}
if(....) {
$retVal['...'] = $this->item->.....();
}
return $retVal;
}
}
/**
* DTO
*/
class Item {
public function __construct(ItemProperties $itemProps) {
$this->setItemProps($itemProps);
}
// If you prefer lazy loading here...maybe make it public
// and remove call from constructor.
private function setItemProps(&$itemProps) {
$properties = $itemProps->getProperties();
foreach($properties AS $propName => $propValue) {
$this->$propName = $propValue;
}
}
}
// Usage:
$itemProps = new ItemProperties($Item);
// set other properties if you need to...
$itemProps->isLogin = false;
$item = new Item($itemProps);
Just came across the latest build of Mono.CSharp and love the promise it offers.
Was able to get the following all worked out:
namespace XAct.Spikes.Duo
{
class Program
{
static void Main(string[] args)
{
CompilerSettings compilerSettings = new CompilerSettings();
compilerSettings.LoadDefaultReferences = true;
Report report = new Report(new Mono.CSharp.ConsoleReportPrinter());
Mono.CSharp.Evaluator e;
e= new Evaluator(compilerSettings, report);
//IMPORTANT:This has to be put before you include references to any assemblies
//our you;ll get a stream of errors:
e.Run("using System;");
//IMPORTANT:You have to reference the assemblies your code references...
//...including this one:
e.Run("using XAct.Spikes.Duo;");
//Go crazy -- although that takes time:
//foreach (Assembly assembly in AppDomain.CurrentDomain.GetAssemblies())
//{
// e.ReferenceAssembly(assembly);
//}
//More appropriate in most cases:
e.ReferenceAssembly((typeof(A).Assembly));
//Exception due to no semicolon
//e.Run("var a = 1+3");
//Doesn't set anything:
//e.Run("a = 1+3;");
//Works:
//e.ReferenceAssembly(typeof(A).Assembly);
e.Run("var a = 1+3;");
e.Run("A x = new A{Name=\"Joe\"};");
var a = e.Evaluate("a;");
var x = e.Evaluate("x;");
//Not extremely useful:
string check = e.GetVars();
//Note that you have to type it:
Console.WriteLine(((A) x).Name);
e = new Evaluator(compilerSettings, report);
var b = e.Evaluate("a;");
}
}
public class A
{
public string Name { get; set; }
}
}
And that was fun...can create a variable in the script's scope, and export the value.
There's just one last thing to figure out... how can I get a value in (eg, a domain entity that I want to apply a Rule script on), without using a static (am thinking of using this in a web app)?
I've seen the use compiled delegates -- but that was for the previous version of Mono.CSharp, and it doesn't seem to work any longer.
Anybody have a suggestion on how to do this with the current version?
Thanks very much.
References:
* Injecting a variable into the Mono.CSharp.Evaluator (runtime compiling a LINQ query from string)
* http://naveensrinivasan.com/tag/mono/
I know it's almost 9 years later, but I think I found a viable solution to inject local variables. It is using a static variable but can still be used by multiple evaluators without collision.
You can use a static Dictionary<string, object> which holds the reference to be injected. Let's say we are doing all this from within our class CsharpConsole:
public class CsharpConsole {
public static Dictionary<string, object> InjectionRepository {get; set; } = new Dictionary<string, object>();
}
The idea is to temporarily place the value in there with a GUID as key so there won't be any conflict between multiple evaluator instances. To inject do this:
public void InjectLocal(string name, object value, string type=null) {
var id = Guid.NewGuid().ToString();
InjectionRepository[id] = value;
type = type ?? value.GetType().FullName;
// note for generic or nested types value.GetType().FullName won't return a compilable type string, so you have to set the type parameter manually
var success = _evaluator.Run($"var {name} = ({type})MyNamespace.CsharpConsole.InjectionRepository[\"{id}\"];");
// clean it up to avoid memory leak
InjectionRepository.Remove(id);
}
Also for accessing local variables there is a workaround using Reflection so you can have a nice [] accessor with get and set:
public object this[string variable]
{
get
{
FieldInfo fieldInfo = typeof(Evaluator).GetField("fields", BindingFlags.NonPublic | BindingFlags.Instance);
if (fieldInfo != null)
{
var fields = fieldInfo.GetValue(_evaluator) as Dictionary<string, Tuple<FieldSpec, FieldInfo>>;
if (fields != null)
{
if (fields.TryGetValue(variable, out var tuple) && tuple != null)
{
var value = tuple.Item2.GetValue(_evaluator);
return value;
}
}
}
return null;
}
set
{
InjectLocal(variable, value);
}
}
Using this trick, you can even inject delegates and functions that your evaluated code can call from within the script. For instance, I inject a print function which my code can call to ouput something to the gui console window:
public delegate void PrintFunc(params object[] o);
public void puts(params object[] o)
{
// call the OnPrint event to redirect the output to gui console
if (OnPrint!=null)
OnPrint(string.Join("", o.Select(x => (x ?? "null").ToString() + "\n").ToArray()));
}
This puts function can now be easily injected like this:
InjectLocal("puts", (PrintFunc)puts, "CsInterpreter2.PrintFunc");
And just be called from within your scripts:
puts(new object[] { "hello", "world!" });
Note, there is also a native function print but it directly writes to STDOUT and redirecting individual output from multiple console windows is not possible.
I'm getting the following error:
'object' does not contain a definition for 'RatingName'
When you look at the anonymous dynamic type, it clearly does have RatingName.
I realize I can do this with a Tuple, but I would like to understand why the error message occurs.
Anonymous types having internal properties is a poor .NET framework design decision, in my opinion.
Here is a quick and nice extension to fix this problem i.e. by converting the anonymous object into an ExpandoObject right away.
public static ExpandoObject ToExpando(this object anonymousObject)
{
IDictionary<string, object> anonymousDictionary = new RouteValueDictionary(anonymousObject);
IDictionary<string, object> expando = new ExpandoObject();
foreach (var item in anonymousDictionary)
expando.Add(item);
return (ExpandoObject)expando;
}
It's very easy to use:
return View("ViewName", someLinq.Select(new { x=1, y=2}.ToExpando());
Of course in your view:
#foreach (var item in Model) {
<div>x = #item.x, y = #item.y</div>
}
I found the answer in a related question. The answer is specified on David Ebbo's blog post Passing anonymous objects to MVC views and accessing them using dynamic
The reason for this is that the
anonymous type being passed in the
controller in internal, so it can only
be accessed from within the assembly
in which it’s declared. Since views
get compiled separately, the dynamic
binder complains that it can’t go over
that assembly boundary.
But if you think about it, this
restriction from the dynamic binder is
actually quite artificial, because if
you use private reflection, nothing is
stopping you from accessing those
internal members (yes, it even work in
Medium trust). So the default dynamic
binder is going out of its way to
enforce C# compilation rules (where
you can’t access internal members),
instead of letting you do what the CLR
runtime allows.
Using ToExpando method is the best solution.
Here is the version that doesn't require System.Web assembly:
public static ExpandoObject ToExpando(this object anonymousObject)
{
IDictionary<string, object> expando = new ExpandoObject();
foreach (PropertyDescriptor propertyDescriptor in TypeDescriptor.GetProperties(anonymousObject))
{
var obj = propertyDescriptor.GetValue(anonymousObject);
expando.Add(propertyDescriptor.Name, obj);
}
return (ExpandoObject)expando;
}
Instead of creating a model from an anonymous type and then trying to convert the anonymous object to an ExpandoObject like this ...
var model = new
{
Profile = profile,
Foo = foo
};
return View(model.ToExpando()); // not a framework method (see other answers)
You can just create the ExpandoObject directly:
dynamic model = new ExpandoObject();
model.Profile = profile;
model.Foo = foo;
return View(model);
Then in your view you set the model type as dynamic #model dynamic and you can access the properties directly :
#Model.Profile.Name
#Model.Foo
I'd normally recommend strongly typed view models for most views, but sometimes this flexibility is handy.
You can use the framework impromptu interface to wrap an anonymous type in an interface.
You'd just return an IEnumerable<IMadeUpInterface> and at the end of your Linq use .AllActLike<IMadeUpInterface>(); this works because it calls the anonymous property using the DLR with a context of the assembly that declared the anonymous type.
Wrote a console application and add Mono.Cecil as reference (you can now add it from NuGet), then write the piece of code:
static void Main(string[] args)
{
var asmFile = args[0];
Console.WriteLine("Making anonymous types public for '{0}'.", asmFile);
var asmDef = AssemblyDefinition.ReadAssembly(asmFile, new ReaderParameters
{
ReadSymbols = true
});
var anonymousTypes = asmDef.Modules
.SelectMany(m => m.Types)
.Where(t => t.Name.Contains("<>f__AnonymousType"));
foreach (var type in anonymousTypes)
{
type.IsPublic = true;
}
asmDef.Write(asmFile, new WriterParameters
{
WriteSymbols = true
});
}
The code above would get the assembly file from input args and use Mono.Cecil to change the accessibility from internal to public, and that would resolve the problem.
We can run the program in the Post Build event of the website. I wrote a blog post about this in Chinese but I believe you can just read the code and snapshots. :)
Based on the accepted answer, I have overridden in the controller to make it work in general and behind the scenes.
Here is the code:
protected override void OnResultExecuting(ResultExecutingContext filterContext)
{
base.OnResultExecuting(filterContext);
//This is needed to allow the anonymous type as they are intenal to the assembly, while razor compiles .cshtml files into a seperate assembly
if (ViewData != null && ViewData.Model != null && ViewData.Model.GetType().IsNotPublic)
{
try
{
IDictionary<string, object> expando = new ExpandoObject();
(new RouteValueDictionary(ViewData.Model)).ToList().ForEach(item => expando.Add(item));
ViewData.Model = expando;
}
catch
{
throw new Exception("The model provided is not 'public' and therefore not avaialable to the view, and there was no way of handing it over");
}
}
}
Now you can just pass an anonymous object as the model, and it will work as expected.
I'm going to do a little bit of stealing from https://stackoverflow.com/a/7478600/37055
If you install-package dynamitey you can do this:
return View(Build<ExpandoObject>.NewObject(RatingName: name, Comment: comment));
And the peasants rejoice.
The reason of RuntimeBinderException triggered, I think there have good answer in other posts. I just focus to explain how I actually make it work.
By refer to answer #DotNetWise and Binding views with Anonymous type collection in ASP.NET MVC,
Firstly, Create a static class for extension
public static class impFunctions
{
//converting the anonymous object into an ExpandoObject
public static ExpandoObject ToExpando(this object anonymousObject)
{
//IDictionary<string, object> anonymousDictionary = new RouteValueDictionary(anonymousObject);
IDictionary<string, object> anonymousDictionary = HtmlHelper.AnonymousObjectToHtmlAttributes(anonymousObject);
IDictionary<string, object> expando = new ExpandoObject();
foreach (var item in anonymousDictionary)
expando.Add(item);
return (ExpandoObject)expando;
}
}
In controller
public ActionResult VisitCount()
{
dynamic Visitor = db.Visitors
.GroupBy(p => p.NRIC)
.Select(g => new { nric = g.Key, count = g.Count()})
.OrderByDescending(g => g.count)
.AsEnumerable() //important to convert to Enumerable
.Select(c => c.ToExpando()); //convert to ExpandoObject
return View(Visitor);
}
In View, #model IEnumerable (dynamic, not a model class), this is very important as we are going to bind the anonymous type object.
#model IEnumerable<dynamic>
#*#foreach (dynamic item in Model)*#
#foreach (var item in Model)
{
<div>x=#item.nric, y=#item.count</div>
}
The type in foreach, I have no error either using var or dynamic.
By the way, create a new ViewModel that is matching the new fields also can be the way to pass the result to the view.
Now in recursive flavor
public static ExpandoObject ToExpando(this object obj)
{
IDictionary<string, object> expandoObject = new ExpandoObject();
new RouteValueDictionary(obj).ForEach(o => expandoObject.Add(o.Key, o.Value == null || new[]
{
typeof (Enum),
typeof (String),
typeof (Char),
typeof (Guid),
typeof (Boolean),
typeof (Byte),
typeof (Int16),
typeof (Int32),
typeof (Int64),
typeof (Single),
typeof (Double),
typeof (Decimal),
typeof (SByte),
typeof (UInt16),
typeof (UInt32),
typeof (UInt64),
typeof (DateTime),
typeof (DateTimeOffset),
typeof (TimeSpan),
}.Any(oo => oo.IsInstanceOfType(o.Value))
? o.Value
: o.Value.ToExpando()));
return (ExpandoObject) expandoObject;
}
Using the ExpandoObject Extension works but breaks when using nested anonymous objects.
Such as
var projectInfo = new {
Id = proj.Id,
UserName = user.Name
};
var workitem = WorkBL.Get(id);
return View(new
{
Project = projectInfo,
WorkItem = workitem
}.ToExpando());
To accomplish this I use this.
public static class RazorDynamicExtension
{
/// <summary>
/// Dynamic object that we'll utilize to return anonymous type parameters in Views
/// </summary>
public class RazorDynamicObject : DynamicObject
{
internal object Model { get; set; }
public override bool TryGetMember(GetMemberBinder binder, out object result)
{
if (binder.Name.ToUpper() == "ANONVALUE")
{
result = Model;
return true;
}
else
{
PropertyInfo propInfo = Model.GetType().GetProperty(binder.Name);
if (propInfo == null)
{
throw new InvalidOperationException(binder.Name);
}
object returnObject = propInfo.GetValue(Model, null);
Type modelType = returnObject.GetType();
if (modelType != null
&& !modelType.IsPublic
&& modelType.BaseType == typeof(Object)
&& modelType.DeclaringType == null)
{
result = new RazorDynamicObject() { Model = returnObject };
}
else
{
result = returnObject;
}
return true;
}
}
}
public static RazorDynamicObject ToRazorDynamic(this object anonymousObject)
{
return new RazorDynamicObject() { Model = anonymousObject };
}
}
Usage in the controller is the same except you use ToRazorDynamic() instead of ToExpando().
In your view to get the entire anonymous object you just add ".AnonValue" to the end.
var project = #(Html.Raw(JsonConvert.SerializeObject(Model.Project.AnonValue)));
var projectName = #Model.Project.Name;
I tried the ExpandoObject but it didn't work with a nested anonymous complex type like this:
var model = new { value = 1, child = new { value = 2 } };
So my solution was to return a JObject to View model:
return View(JObject.FromObject(model));
and convert to dynamic in .cshtml:
#using Newtonsoft.Json.Linq;
#model JObject
#{
dynamic model = (dynamic)Model;
}
<span>Value of child is: #model.child.value</span>
Is anybody using JSON.NET with nHibernate? I notice that I am getting errors when I try to load a class with child collections.
I was facing the same problem so I tried to use #Liedman's code but the GetSerializableMembers() was never get called for the proxied reference.
I found another method to override:
public class NHibernateContractResolver : DefaultContractResolver
{
protected override JsonContract CreateContract(Type objectType)
{
if (typeof(NHibernate.Proxy.INHibernateProxy).IsAssignableFrom(objectType))
return base.CreateContract(objectType.BaseType);
else
return base.CreateContract(objectType);
}
}
We had this exact problem, which was solved with inspiration from Handcraftsman's response here.
The problem arises from JSON.NET being confused about how to serialize NHibernate's proxy classes. Solution: serialize the proxy instances like their base class.
A simplified version of Handcraftsman's code goes like this:
public class NHibernateContractResolver : DefaultContractResolver {
protected override List<MemberInfo> GetSerializableMembers(Type objectType) {
if (typeof(INHibernateProxy).IsAssignableFrom(objectType)) {
return base.GetSerializableMembers(objectType.BaseType);
} else {
return base.GetSerializableMembers(objectType);
}
}
}
IMHO, this code has the advantage of still relying on JSON.NET's default behaviour regarding custom attributes, etc. (and the code is a lot shorter!).
It is used like this
var serializer = new JsonSerializer{
ReferenceLoopHandling = ReferenceLoopHandling.Ignore,
ContractResolver = new NHibernateContractResolver()
};
StringWriter stringWriter = new StringWriter();
JsonWriter jsonWriter = new Newtonsoft.Json.JsonTextWriter(stringWriter);
serializer.Serialize(jsonWriter, objectToSerialize);
string serializedObject = stringWriter.ToString();
Note: This code was written for and used with NHibernate 2.1. As some commenters have pointed out, it doesn't work out of the box with later versions of NHibernate, you will have to make some adjustments. I will try to update the code if I ever have to do it with later versions of NHibernate.
I use NHibernate with Json.NET and noticed that I was getting inexplicable "__interceptors" properties in my serialized objects. A google search turned up this excellent solution by Lee Henson which I adapted to work with Json.NET 3.5 Release 5 as follows.
public class NHibernateContractResolver : DefaultContractResolver
{
private static readonly MemberInfo[] NHibernateProxyInterfaceMembers = typeof(INHibernateProxy).GetMembers();
protected override List<MemberInfo> GetSerializableMembers(Type objectType)
{
var members = base.GetSerializableMembers(objectType);
members.RemoveAll(memberInfo =>
(IsMemberPartOfNHibernateProxyInterface(memberInfo)) ||
(IsMemberDynamicProxyMixin(memberInfo)) ||
(IsMemberMarkedWithIgnoreAttribute(memberInfo, objectType)) ||
(IsMemberInheritedFromProxySuperclass(memberInfo, objectType)));
var actualMemberInfos = new List<MemberInfo>();
foreach (var memberInfo in members)
{
var infos = memberInfo.DeclaringType.BaseType.GetMember(memberInfo.Name);
actualMemberInfos.Add(infos.Length == 0 ? memberInfo : infos[0]);
}
return actualMemberInfos;
}
private static bool IsMemberDynamicProxyMixin(MemberInfo memberInfo)
{
return memberInfo.Name == "__interceptors";
}
private static bool IsMemberInheritedFromProxySuperclass(MemberInfo memberInfo, Type objectType)
{
return memberInfo.DeclaringType.Assembly == typeof(INHibernateProxy).Assembly;
}
private static bool IsMemberMarkedWithIgnoreAttribute(MemberInfo memberInfo, Type objectType)
{
var infos = typeof(INHibernateProxy).IsAssignableFrom(objectType)
? objectType.BaseType.GetMember(memberInfo.Name)
: objectType.GetMember(memberInfo.Name);
return infos[0].GetCustomAttributes(typeof(JsonIgnoreAttribute), true).Length > 0;
}
private static bool IsMemberPartOfNHibernateProxyInterface(MemberInfo memberInfo)
{
return Array.Exists(NHibernateProxyInterfaceMembers, mi => memberInfo.Name == mi.Name);
}
}
To use it just put an instance in the ContractResolver property of your JsonSerializer. The circular dependency problem noted by jishi can be resolved by setting the ReferenceLoopHandling property to ReferenceLoopHandling.Ignore . Here's an extension method that can be used to serialize objects using Json.Net
public static void SerializeToJsonFile<T>(this T itemToSerialize, string filePath)
{
using (StreamWriter streamWriter = new StreamWriter(filePath))
{
using (JsonWriter jsonWriter = new JsonTextWriter(streamWriter))
{
jsonWriter.Formatting = Formatting.Indented;
JsonSerializer serializer = new JsonSerializer
{
NullValueHandling = NullValueHandling.Ignore,
ReferenceLoopHandling = ReferenceLoopHandling.Ignore,
ContractResolver = new NHibernateContractResolver(),
};
serializer.Serialize(jsonWriter, itemToSerialize);
}
}
}
Are you getting a circular dependancy-error? How do you ignore objects from serialization?
Since lazy loading generates a proxy-objects, any attributes your class-members have will be lost. I ran into the same issue with Newtonsoft JSON-serializer, since the proxy-object didn't have the [JsonIgnore] attributes anymore.
You will probably want to eager load most of the object so that it can be serialized:
ICriteria ic = _session.CreateCriteria(typeof(Person));
ic.Add(Restrictions.Eq("Id", id));
if (fetchEager)
{
ic.SetFetchMode("Person", FetchMode.Eager);
}
A nice way to do this is to add a bool to the constructor (bool isFetchEager) of your data provider method.
I'd say this is a design problem in my opinion. Because NH makes connections to the database underneath all and has proxies in the middle, it is not good for the transparency of your application to serialize them directly (and as you can see Json.NET does not like them at all).
You should not serialize the entities themselves, but you should convert them into "view" objects or POCO or DTO objects (whatever you want to call them) and then serialize these.
The difference is that while NH entity may have proxies, lazy attributes, etc. View objects are simple objects with only primitives which are serializable by default.
How to manage FKs?
My personal rule is:
Entity level: Person class and with a Gender class associated
View level: Person view with GenderId and GenderName properties.
This means that you need to expand your properties into primitives when converting to view objects. This way also your json objects are simpler and easier to handle.
When you need to push the changes to the DB, in my case I use AutoMapper and do a ValueResolver class which can convert your new Guid to the Gender object.
UPDATE: Check http://blog.andrewawhitaker.com/blog/2014/06/19/queryover-series-part-4-transforming/ for a way to get the view directly (AliasToBean) from NH. This would be a boost in the DB side.
The problem can happen when NHibernate wraps the nested collection properties in a PersistentGenericBag<> type.
The GetSerializableMembers and CreateContract overrides cannot detect that these nested collection properties are "proxied". One way to resolve this is to override the CreateProperty method. The trick is to get the value from the property using reflection and test whether the type is of PersistentGenericBag. This method also has the ability to filter any properties that generated exceptions.
public class NHibernateContractResolver : DefaultContractResolver
{
protected override JsonProperty CreateProperty(MemberInfo member, MemberSerialization memberSerialization)
{
JsonProperty property = base.CreateProperty(member, memberSerialization);
property.ShouldSerialize = instance =>
{
try
{
PropertyInfo prop = (PropertyInfo)member;
if (prop.CanRead)
{
var value = prop.GetValue(instance, null);
if (value != null && typeof(NHibernate.Collection.Generic.PersistentGenericBag<>).IsSubclassOfRawGeneric(value.GetType()))
return false;
return true;
}
}
catch
{ }
return false;
};
return property;
}
}
The IsSubclassOfRawGeneric extension used above:
public static class TypeExtensions
{
public static bool IsSubclassOfRawGeneric(this Type generic, Type? toCheck)
{
while (toCheck != null && toCheck != typeof(object))
{
var cur = toCheck.IsGenericType ? toCheck.GetGenericTypeDefinition() : toCheck;
if (generic == cur)
{
return true;
}
toCheck = toCheck?.BaseType;
}
return false;
}
}
If you serialize objects that contain NHibernate proxy classes you might end up downloading the whole database, because once the property is accessed NHibernate would trigger a request to the database.
I've just implemented a Unit of Work for NHibernate: NHUnit that fixes two of the most annoying issues from NHibernate: proxy classes and cartesian product when using fetch.
How would you use this?
var customer = await _dbContext.Customers.Get(customerId) //returns a wrapper to configure the query
.Include(c => c.Addresses.Single().Country, //include Addresses and Country
c => c.PhoneNumbers.Single().PhoneNumberType) //include all PhoneNumbers with PhoneNumberType
.Unproxy() //instructs the framework to strip all the proxy classes when the Value is returned
.Deferred() //instructs the framework to delay execution (future)
.ValueAsync(token); //this is where all deferred queries get executed
The above code is basically configuring a query: return a customer by id with multiple child objects which should be executed with other queries (futures) and the returned result should be stripped of NHibernate proxies. The query gets executed when ValueAsync is called.
NHUnit determines if it should do join with the main query, create new future queries or make use of batch fetch.
There is a simple example project on Github to show you how to use NHUnit package. If others are interested in this project I will invest more time to make it better.
This is what I use:
Have a marker interface and inherit it on your entities, e.g. in my case empty IEntity.
We will use the marker interface to detect NHibernate entity types in the contract resolver.
public class CustomerEntity : IEntity { ... }
Create a custom contract resolver for JSON.NET
public class NHibernateProxyJsonValueProvider : IValueProvider {
private readonly IValueProvider _valueProvider;
public NHibernateProxyJsonValueProvider(IValueProvider valueProvider)
{
_valueProvider = valueProvider;
}
public void SetValue(object target, object value)
{
_valueProvider.SetValue(target, value);
}
private static (bool isProxy, bool isInitialized) GetProxy(object proxy)
{
// this is pretty much what NHibernateUtil.IsInitialized() does.
switch (proxy)
{
case INHibernateProxy hibernateProxy:
return (true, !hibernateProxy.HibernateLazyInitializer.IsUninitialized);
case ILazyInitializedCollection initializedCollection:
return (true, initializedCollection.WasInitialized);
case IPersistentCollection persistentCollection:
return (true, persistentCollection.WasInitialized);
default:
return (false, false);
}
}
public object GetValue(object target)
{
object value = _valueProvider.GetValue(target);
(bool isProxy, bool isInitialized) = GetProxy(value);
if (isProxy)
{
if (isInitialized)
{
return value;
}
if (value is IEnumerable)
{
return Enumerable.Empty<object>();
}
return null;
}
return value;
}
}
public class NHibernateContractResolver : CamelCasePropertyNamesContractResolver {
protected override JsonContract CreateContract(Type objectType)
{
if (objectType.IsAssignableTo(typeof(IEntity)))
{
return base.CreateObjectContract(objectType);
}
return base.CreateContract(objectType);
}
protected override JsonProperty CreateProperty(MemberInfo member, MemberSerialization memberSerialization)
{
JsonProperty property = base.CreateProperty(member, memberSerialization);
property.ValueProvider = new NHibernateProxyJsonValueProvider(property.ValueProvider);
return property;
}
}
Normal uninitialized lazy loaded properties will result in null in the json output.
Collection uninitialized lazy loaded properties will result in an [] empty array in json.
So for a lazy loaded property to appear in the json output you need to eagerly load it in the query or in code before serialization.
Usage:
JsonConvert.SerializeObject(entityToSerialize, new JsonSerializerSettings() {
ContractResolver = new NHibernateContractResolver()
});
Or globally in in ASP.NET Core Startup class
services.AddNewtonsoftJson(options =>
{
options.SerializerSettings.ContractResolver = new NHibernateContractResolver();
});
Using:
NET 5.0
NHibernate 5.3.8
JSON.NET latest via ASP.NET Core