I have the following scenario in my code:
class A {
/// <summary>
/// returns the total number of frames that the consumer can accept
/// </summary>
/// <returns></returns>
virtual int GetRenderBufferSizeInFrames() = 0;
}
class B : public A {
int GetRenderBufferSizeInFrames();
}
void F() {
B BInstance;
BInstance.GetRenderBufferSizeInFrames(); // VC++ does not show the information about
// the method
}
When I hover the mouse over the function call, VC++ does not show me the info on the function. Is there a way to fix that? Logically it should be doing that, no?
No, you need to be explicit about that.
Try adding <inheritdoc/> to the derived method.
class B : public A {
/// <inheritdoc />
int GetRenderBufferSizeInFrames();
}
As a side note, I suggest to use an override specifier, to ensure you don't have a typo in the method name and make it visibly clear that this is overriding a virtual method from the base class.
Related
I am implementing a system based on SignalR that will be pushing client events, for message serialization I would want to use MessagePack. When trying to implement the messaging I have run into a problem where SignalR fails to deserialize the messages on the client.
The messages are polymorphic and described with Union attributes, the standard MessagePack Serializer have no problem serializing and deserializing the messages BUT in case of Signal R it fails with error.
The error reported is System.InvalidOperationException: Invalid Union data was detected.
On the client serialization only works when using the actual class, if I try to use the interface or base class then the error appears.
Classes
[DataContract()]
[MessagePackObject()]
[Union(0,typeof(EntityChangeEventMessage))]
public abstract class EntityEventMessage : IEntityEventMessage
{
}
[DataContract()]
[MessagePackObject()]
public class EntityChangeEventMessage : EntityEventMessage
{
#region PROPERTIES
/// <summary>
/// Gets entity id.
/// </summary>
[DataMember(Order = 1)]
[Key(1)]
public int EntityId
{
get; set;
}
/// <summary>
/// Gets event type.
/// </summary>
/// <remarks>
/// This value identifies database operation such as create,delete,update etc.
/// </remarks>
[DataMember(Order = 2)]
[Key(2)]
public int EventType
{
get; set;
}
/// <summary>
/// Gets entity type name.
/// </summary>
[DataMember(Order = 3)]
[Key(3)]
public string EntityType
{
get; set;
}
#endregion
}
[Union(0,typeof(EntityChangeEventMessage))]
public interface IEntityEventMessage
{
}
So this works
connection.On("EntityEvent", (EntityChangeEventMessage d)
This dont work
connection.On("EntityEvent", (IEntityEventMessaged)
So in general it looks like the problem should be in the Microsoft.AspNetCore.SignalR.Protocols.MessagePack library ?
Anyone have implemented such functionality with success ?
Currently SignalR does not support polymorphism with MessagePack, more info here.
We have several environments that had their own run settings when we used MSTest. Since Microsoft is abandoning MSTest we are switching to xUnit. Whether it's through a runsettings or a command line property, I need a way to specify TestRunParameters in my xUnit test. Does xUnit have a native way to do that like MSTest or do I need to come up with my own solution?
While you can still use RunSettings to control some aspects of vstest.console while using xUnit the current version does not have a native way to pass in parameters. I believe v3 is going to have some kind of parameter passing.
For now you could use environment variables but if you are running multiple tests sets in parallel on the same system you would have conflicts.
I use a base class which reads in a TestSettings.json file with the settings for that test set. Using the following code I am able to pass in new types and have them read in by the base class json reader.
/// <inheritdoc />
/// <summary>
/// Common TestBase which uses CommonSettingsModel. Use TestBase<T> to override with custom settings Type.
/// </summary>
public abstract class TestBase : TestBase<CommonSettingsModel>
{
}
/// <inheritdoc />
/// <summary>
/// Common TestBase for loading settings.
/// </summary>
/// <typeparam name="T">Type to read TestSettings.json file</typeparam>
public abstract class TestBase<T> where T : ICommonSettings, new()
{
/// <inheritdoc />
/// <summary>
/// Constructor loads Settings T
/// </summary>
protected TestBase()
{
Settings = SettingsUtil.GetSettings<T>();
}
/// <summary>
/// Settings T loaded from TestSettings.json
/// </summary>
protected T Settings { get; }
}
You could also do the same type of thing with a Class or AssemblyFixture for the tests.
public class DatabaseFixture : IDisposable
{
public DatabaseFixture()
{
Db = new SqlConnection("MyConnectionString");
// ... initialize data in the test database ...
}
public void Dispose()
{
// ... clean up test data from the database ...
}
public SqlConnection Db { get; private set; }
}
public class MyDatabaseTests : IClassFixture<DatabaseFixture>
{
DatabaseFixture fixture;
public MyDatabaseTests(DatabaseFixture fixture)
{
this.fixture = fixture;
}
// ... write tests, using fixture.Db to get access to the SQL Server ...
}
https://xunit.net/docs/shared-context
I am trying to update an entity with a FK relationship in EntityFramework 4.3 Code First.
I try to attach to the related entites by calling: Entry(item).State = EntityState.Unchanged
I get the following exception: An object with the same key already exists in the ObjectStateManager. The ObjectStateManager cannot track multiple objects with the same key.
I do not update these items nor have an id property for them on my main entity.
Is it possible to know which entities are attached or not ?
Thanks in advance,
Radu
You can find the answer here.
public bool Exists<T>(T entity) where T : class
{
return this.Set<T>().Local.Any(e => e == entity);
}
Place that code into your context or you can turn it into an extension like so.
public static bool Exists<TContext, TEntity>(this TContext context, TEntity entity)
where TContext : DbContext
where TEntity : class
{
return context.Set<TEntity>().Local.Any(e => e == entity);
}
You can use this method:
/// <summary>
/// Determines whether the specified entity key is attached.
/// </summary>
/// <param name="context">The context.</param>
/// <param name="key">The key.</param>
/// <returns>
/// <c>true</c> if the specified context is attached; otherwise, <c>false</c>.
/// </returns>
internal static bool IsAttached(this ObjectContext context, EntityKey key)
{
if (key == null)
{
throw new ArgumentNullException("key");
}
ObjectStateEntry entry;
if (context.ObjectStateManager.TryGetObjectStateEntry(key, out entry))
{
return (entry.State != EntityState.Detached);
}
return false;
}
For example:
if (!_objectContext.IsAttached(entity.EntityKey))
{
_objectContext.Attach(entity);
}
If you have arrived here from an EF Core Lazy Loading scenario in which Navigation properties were filled in a data layer via DbSet<>.Include() clause(s) while the Entity was attached to a DbContext and then that Entity was detached and passed up to a business layer, consider adding something like this to your DbContext.OnConfiguring(DbContextOptionsBuilder optionsBuilder) method:
optionsBuilder.ConfigureWarnings(warn => warn.Ignore(CoreEventId.LazyLoadOnDisposedContextWarning));
The error will be ignored and the values that were originally Include()d will be returned.
I use this extension method since I needed to check tracking based on values, not based on instance
internal static class DBExtensions
{
internal static bool IsAttached<TEntity>(this DbSet<TEntity> dbSet, Func<TEntity, bool> condition) where TEntity : class
{
return dbSet.Local.Any(condition);
}
}
Usage:
if (!context.Items.IsAttached(y => y.ItemId == item.ItemId))
{
context.Items.Attach(item);
}
I have a MVC 3 web application, where I am using the Entity Framework for the data access. Furthermore, I have made a simple use of the repository pattern, where e.g. all Product related stuff is handled in the "ProductRepository" and all User related stuff is handled in the "UserRepository".
Thus, I am using the UNITY container, to make a singleton instance of the DataContext, which I inject into each of the repositories. A quick search on Google, and everyone recommends you to NOT use a singleton instance of the DataContext, as it might give you some memory leaks in the future.
So, inspired by this post, making a singleton instance of the DataContext for each web request is the answer (please correct me if I am wrong!)
http://blogs.microsoft.co.il/blogs/gilf/archive/2010/05/18/how-to-manage-objectcontext-per-request-in-asp-net.aspx
However, UNITY does not support the "Per-web-request" lifetime manager. But, it is possible to implement your own custom lifetime manager, which handles this for you. Actually, this is discussed in this post :
Singleton Per Call Context (Web Request) in Unity
The question is, I have now implemented the custom lifetime manager as described in the above post, but I am unsure if this is the way to do it. I am also wondering about where the datacontext instance is disposed in the provided solution? Am I missing out something?
Is there actually a better way of solving my "issue"?
Thanks!
** Added information about my implementation **
The following is snippets from my Global.asax, Controller and Repository. This gives a clear picture of my implementation.
Global.asax
var container = new UnityContainer();
container
.RegisterType<ProductsRepository>(new ContainerControlledLifetimeManager())
.RegisterType<CategoryRepository>(new ContainerControlledLifetimeManager())
.RegisterType<MyEntities>(new PerResolveLifetimeManager(), dbConnectionString)
Controller
private ProductsRepository _productsRepository;
private CategoryRepository _categoryRepository;
public ProductsController(ProductsRepository productsRepository, CategoryRepository categoryRepository)
{
_productsRepository = productsRepository;
_categoryRepository = categoryRepository;
}
public ActionResult Index()
{
ProductCategory category = _categoryRepository.GetProductCategory(categoryId);
.
.
.
}
protected override void Dispose(bool disposing)
{
base.Dispose(disposing);
_productsRepository.Dispose();
_categoryRepository.Dispose();
}
Product Repository
public class ProductsRepository : IDisposable
{
private MyEntities _db;
public ProductsRepository(MyEntities db)
{
_db = db;
}
public Product GetProduct(Guid productId)
{
return _db.Product.Where(x => x.ID == productId).FirstOrDefault();
}
public void Dispose()
{
this._db.Dispose();
}
Controller Factory
public class UnityControllerFactory : DefaultControllerFactory
{
IUnityContainer _container;
public UnityControllerFactory(IUnityContainer container)
{
_container = container;
}
protected override IController GetControllerInstance(RequestContext requestContext, Type controllerType)
{
if (controllerType == null)
{
throw new HttpException(404, String.Format("The controller for path '{0}' could not be found" +
"or it does not implement IController.",
requestContext.HttpContext.Request.Path));
}
return _container.Resolve(controllerType) as IController;
}
}
Addition information
Hi, I will post additional links that I come across, concerning the related issue and solution suggestions:
https://github.com/geersch/EntityFrameworkObjectContext
http://dotnetslackers.com/articles/ado_net/Managing-Entity-Framework-ObjectContext-lifespan-and-scope-in-n-layered-ASP-NET-applications.aspx
attaching linq to sql datacontext to httpcontext in business layer
http://weblogs.asp.net/shijuvarghese/archive/2008/10/24/asp-net-mvc-tip-dependency-injection-with-unity-application-block.aspx
http://msdn.microsoft.com/en-us/library/bb738470.aspx
Yes do not share context and use one context per request. You can also check linked questions in that post to see all problems which a shared context caused.
Now about Unity. Idea of PerCallContextLifetimeManager works but I think provided implementation will not work for more than one object. You should use PerHttpRequestLifetimeManager directly:
public class PerHttpRequestLifetime : LifetimeManager
{
// This is very important part and the reason why I believe mentioned
// PerCallContext implementation is wrong.
private readonly Guid _key = Guid.NewGuid();
public override object GetValue()
{
return HttpContext.Current.Items[_key];
}
public override void SetValue(object newValue)
{
HttpContext.Current.Items[_key] = newValue;
}
public override void RemoveValue()
{
var obj = GetValue();
HttpContext.Current.Items.Remove(obj);
}
}
Be aware that Unity will not dispose context for you. Also be aware that default UnityContainer implementation will never call RemoveValue method.
If your implementation resolves all repositories in single Resolve call (for example if your controllers receives instances of repositories in constructor and you are resolving controllers) you don't need this lifetime manager. In such case use build-in (Unity 2.0) PerResolveLifetimeManager.
Edit:
I see pretty big problem in your provided configuration of UnityContainer. You are registering both repositories with ContainerControllerLifetimeManager. This lifetime manager means Singleton instance per container lifetime. It means that both repositories will be instantiated only once and instance will be stored and reused for subsequent calls. Because of that it doesn't matter what lifetime did you assign to MyEntities. It is injected to repositories' constructors which will be called only once. Both repositories will use still that single instance of MyEntities created during their construction = they will use single instance for whole lifetime of your AppDomain. That is the worst scenario you can achieve.
Rewrite your configuration this way:
var container = new UnityContainer();
container
.RegisterType<ProductsRepository>()
.RegisterType<CategoryRepository>()
.RegisterType<MyEntities>(new PerResolveLifetimeManager(), dbConnectionString);
Why this is enough? You are resolving controller which is dependent on repsitories but no repository instance is needed more then once so you can use default TransientLifetimeManager which will create new instance for each call. Because of that repository constructor is called and MyEntities instance must be resolved. But you know that multiple repositories can need this instance so you will set it with PerResolveLifetimeManager => each resolving of controller will produce only one instance of MyEntities.
As of Unity 3, there is already a built-in lifetime manager per http request.
PerRequestLifetimeManager
A LifetimeManager that holds onto the instance given to it during the lifetime of a single HTTP request. This lifetime manager enables you to create instances of registered types that behave like singletons within the scope of an HTTP request. See remarks for important usage information.
Remarks by MSDN
Although the PerRequestLifetimeManager lifetime manager works correctly and can help in working with stateful or thread-unsafe dependencies within the scope of an HTTP request, it is generally not a good idea to use it when it can be avoided, as it can often lead to bad practices or hard to find bugs in the end-user's application code when used incorrectly.
It is recommended that the dependencies you register are stateless and if there is a need to share common state between several objects during the lifetime of an HTTP request, then you can have a stateless service that explicitly stores and retrieves this state using the Items collection of the Current object.
The remarks say that even you are forced to use a single context per service (facade service), you should keep your service calls stateless.
Unity 3 is for .NET 4.5 by the way.
I believe the sample code shown on NerdDinner: DI in MVC using Unity for its HttpContextLifetimeManager should meet your needs.
I don't want to unnecessarily discourage you and by all means experiment but if you go ahead and use singleton instances of DataContext make sure you nail it.
It can appear to work fine on your dev environment but it could be failing to close connections properly. This will be hard to see without the load of a production environment. On a production environment with high load, undisposed connections will cause huge memory leaks and then high CPU trying to allocate new memory.
Have you considered what you are gaining from a connection per request pattern? How much performance there is to gain from opening/closing a connection once over say 3-4 times in a request? Worth the hassle? Also this makes lazy loading fails (read database queries in your view) a lot easier offences to make.
Sorry if this came across discouraging. Go for it if you really see the benefit. I'm just warning you that it could backfire quite seriously if you get it wrong so be warned. Something like entity profiler will be invaluable to getting it right - it tells you number of connections opened and closed - amongst other very useful things.
I saw question and answer few times ago. It is dated. Unity.MVC3 has life time manager as HierarchicalLifetimeManager.
container.RegisterType<OwnDbContext>(
"",
new HierarchicalLifetimeManager(),
new InjectionConstructor(connectionString)
);
and it works nice.
I would propose to solve it like this:
http://forums.asp.net/t/1644386.aspx/1
Best regards
I solved this by using Castle.DynamicProxy. I needed to have certain dependencies be injected "On Demand" meaning they needed to be resolved at time of use, not at time of "Depender" build up.
To do this I configure my container like so:
private void UnityRegister(IUnityContainer container)
{
container.RegisterType<HttpContextBase>(new OnDemandInjectionFactory<HttpContextBase>(c => new HttpContextWrapper(HttpContext.Current)));
container.RegisterType<HttpRequestBase>(new OnDemandInjectionFactory<HttpRequestBase>(c => new HttpRequestWrapper(HttpContext.Current.Request)));
container.RegisterType<HttpSessionStateBase>(new OnDemandInjectionFactory<HttpSessionStateBase>(c => new HttpSessionStateWrapper(HttpContext.Current.Session)));
container.RegisterType<HttpServerUtilityBase>(new OnDemandInjectionFactory<HttpServerUtilityBase>(c => new HttpServerUtilityWrapper(HttpContext.Current.Server)));
}
The idea being that I provide a method to retrieve the instance "on demand." The lambda gets invoked whenever any of the methods of the instance are used. The Dependent object is actually holding a reference to a proxied object, no the object itself.
OnDemandInjectionFactory:
internal class OnDemandInjectionFactory<T> : InjectionFactory
{
public OnDemandInjectionFactory(Func<IUnityContainer, T> proxiedObjectFactory) : base((container, type, name) => FactoryFunction(container, type, name, proxiedObjectFactory))
{
}
private static object FactoryFunction(IUnityContainer container, Type type, string name, Func<IUnityContainer, T> proxiedObjectFactory)
{
var interceptor = new OnDemandInterceptor<T>(container, proxiedObjectFactory);
var proxyGenerator = new ProxyGenerator();
var proxy = proxyGenerator.CreateClassProxy(type, interceptor);
return proxy;
}
}
OnDemandInterceptor:
internal class OnDemandInterceptor<T> : IInterceptor
{
private readonly Func<IUnityContainer, T> _proxiedInstanceFactory;
private readonly IUnityContainer _container;
public OnDemandInterceptor(IUnityContainer container, Func<IUnityContainer, T> proxiedInstanceFactory)
{
_proxiedInstanceFactory = proxiedInstanceFactory;
_container = container;
}
public void Intercept(IInvocation invocation)
{
var proxiedInstance = _proxiedInstanceFactory.Invoke(_container);
var types = invocation.Arguments.Select(arg => arg.GetType()).ToArray();
var method = typeof(T).GetMethod(invocation.Method.Name, types);
invocation.ReturnValue = method.Invoke(proxiedInstance, invocation.Arguments);
}
}
In Unity3, if you want to use
PerRequestLifetimeManager
You need to register UnityPerRequestHttpModule
I do this by using WebActivatorEx, the code is as below:
using System.Linq;
using System.Web.Mvc;
using Microsoft.Practices.Unity.Mvc;
using MyNamespace;
[assembly: WebActivatorEx.PreApplicationStartMethod(typeof(UnityWebActivator), "Start")]
[assembly: WebActivatorEx.ApplicationShutdownMethod(typeof(UnityWebActivator), "Shutdown")]
namespace MyNamespace
{
/// <summary>Provides the bootstrapping for integrating Unity with ASP.NET MVC.</summary>
public static class UnityWebActivator
{
/// <summary>Integrates Unity when the application starts.</summary>
public static void Start()
{
var container = UnityConfig.GetConfiguredContainer();
FilterProviders.Providers.Remove(FilterProviders.Providers.OfType<FilterAttributeFilterProvider>().First());
FilterProviders.Providers.Add(new UnityFilterAttributeFilterProvider(container));
DependencyResolver.SetResolver(new UnityDependencyResolver(container));
// TODO: Uncomment if you want to use PerRequestLifetimeManager
Microsoft.Web.Infrastructure.DynamicModuleHelper.DynamicModuleUtility.RegisterModule(typeof(UnityPerRequestHttpModule));
}
/// <summary>Disposes the Unity container when the application is shut down.</summary>
public static void Shutdown()
{
var container = UnityConfig.GetConfiguredContainer();
container.Dispose();
}
}
}
PerRequestLifetimeManager and UnityPerRequestHttpModule classes are in Unity.Mvc package which has a dependency on ASP.NET MVC. If you don't want to have that dependency (e.g. you are using Web API) you will have to copy-paste them in to your app.
If you do that, don't forget the register the HttpModule.
Microsoft.Web.Infrastructure.DynamicModuleHelper.DynamicModuleUtility.RegisterModule(typeof(UnityPerRequestHttpModule));
Edit:
I'll include the classes here before CodePlex shuts down:
// Copyright (c) Microsoft Corporation. All rights reserved. See License.txt in the project root for license information.
using System;
using System.Collections.Generic;
using System.Diagnostics.CodeAnalysis;
using System.Linq;
using System.Web;
using Microsoft.Practices.Unity.Mvc.Properties;
using Microsoft.Practices.Unity.Utility;
namespace Microsoft.Practices.Unity.Mvc
{
/// <summary>
/// Implementation of the <see cref="IHttpModule"/> interface that provides support for using the
/// <see cref="PerRequestLifetimeManager"/> lifetime manager, and enables it to
/// dispose the instances after the HTTP request ends.
/// </summary>
public class UnityPerRequestHttpModule : IHttpModule
{
private static readonly object ModuleKey = new object();
internal static object GetValue(object lifetimeManagerKey)
{
var dict = GetDictionary(HttpContext.Current);
if (dict != null)
{
object obj = null;
if (dict.TryGetValue(lifetimeManagerKey, out obj))
{
return obj;
}
}
return null;
}
internal static void SetValue(object lifetimeManagerKey, object value)
{
var dict = GetDictionary(HttpContext.Current);
if (dict == null)
{
dict = new Dictionary<object, object>();
HttpContext.Current.Items[ModuleKey] = dict;
}
dict[lifetimeManagerKey] = value;
}
/// <summary>
/// Disposes the resources used by this module.
/// </summary>
public void Dispose()
{
}
/// <summary>
/// Initializes a module and prepares it to handle requests.
/// </summary>
/// <param name="context">An <see cref="HttpApplication"/> that provides access to the methods, properties,
/// and events common to all application objects within an ASP.NET application.</param>
[SuppressMessage("Microsoft.Design", "CA1062:Validate arguments of public methods", MessageId = "0", Justification = "Validated with Guard class")]
public void Init(HttpApplication context)
{
Guard.ArgumentNotNull(context, "context");
context.EndRequest += OnEndRequest;
}
private void OnEndRequest(object sender, EventArgs e)
{
var app = (HttpApplication)sender;
var dict = GetDictionary(app.Context);
if (dict != null)
{
foreach (var disposable in dict.Values.OfType<IDisposable>())
{
disposable.Dispose();
}
}
}
private static Dictionary<object, object> GetDictionary(HttpContext context)
{
if (context == null)
{
throw new InvalidOperationException(Resources.ErrorHttpContextNotAvailable);
}
var dict = (Dictionary<object, object>)context.Items[ModuleKey];
return dict;
}
}
}
// Copyright (c) Microsoft Corporation. All rights reserved. See License.txt in the project root for license information.
using System;
using Microsoft.Practices.Unity.Mvc;
namespace Microsoft.Practices.Unity
{
/// <summary>
/// A <see cref="LifetimeManager"/> that holds onto the instance given to it during
/// the lifetime of a single HTTP request.
/// This lifetime manager enables you to create instances of registered types that behave like
/// singletons within the scope of an HTTP request.
/// See remarks for important usage information.
/// </summary>
/// <remarks>
/// <para>
/// Although the <see cref="PerRequestLifetimeManager"/> lifetime manager works correctly and can help
/// in working with stateful or thread-unsafe dependencies within the scope of an HTTP request, it is
/// generally not a good idea to use it when it can be avoided, as it can often lead to bad practices or
/// hard to find bugs in the end-user's application code when used incorrectly.
/// It is recommended that the dependencies you register are stateless and if there is a need to share
/// common state between several objects during the lifetime of an HTTP request, then you can
/// have a stateless service that explicitly stores and retrieves this state using the
/// <see cref="System.Web.HttpContext.Items"/> collection of the <see cref="System.Web.HttpContext.Current"/> object.
/// </para>
/// <para>
/// For the instance of the registered type to be disposed automatically when the HTTP request completes,
/// make sure to register the <see cref="UnityPerRequestHttpModule"/> with the web application.
/// To do this, invoke the following in the Unity bootstrapping class (typically UnityMvcActivator.cs):
/// <code>DynamicModuleUtility.RegisterModule(typeof(UnityPerRequestHttpModule));</code>
/// </para>
/// </remarks>
public class PerRequestLifetimeManager : LifetimeManager
{
private readonly object lifetimeKey = new object();
/// <summary>
/// Retrieves a value from the backing store associated with this lifetime policy.
/// </summary>
/// <returns>The desired object, or null if no such object is currently stored.</returns>
public override object GetValue()
{
return UnityPerRequestHttpModule.GetValue(this.lifetimeKey);
}
/// <summary>
/// Stores the given value into the backing store for retrieval later.
/// </summary>
/// <param name="newValue">The object being stored.</param>
public override void SetValue(object newValue)
{
UnityPerRequestHttpModule.SetValue(this.lifetimeKey, newValue);
}
/// <summary>
/// Removes the given object from the backing store.
/// </summary>
public override void RemoveValue()
{
var disposable = this.GetValue() as IDisposable;
if (disposable != null)
{
disposable.Dispose();
}
UnityPerRequestHttpModule.SetValue(this.lifetimeKey, null);
}
}
}
It appears that the RemoteAttribute validator introduced in ASP.NET MVC 3 does not validate on the server-side, only via JavaScript. If you turn off JS in your browser, you will find that on model binding, the validation controller action (that you specified when decorating a model property with the RemoteAttribute) will not be hit. In fact, if you inspect the source code for the RemoteAttribute, you will find the IsValid methods just returns true in all cases.
This seems to be quite an omission - I think most people would assume that the RemoteAttribute would work like all the other built-in validators and validate on both client-side and server-side. Instead, you must manually call your remote validation logic in your controller action.
Are people aware of this and has anyone tried to address it?
I have subclassed RemoteAttribute and overridden the IsValid method where I have access to RouteData, RouteName and Routes as well as a GetUrl method that returns the action URL. I was thinking about using reflection to call the action and get the result so I can see if it is valid or not, but are there any built-in methods that I can use without resorting to reflection?
Maybe its not the best code. If you have some recommendations please let me know.
Developed #MVC4
Model property with custom attribute
[CustomRemote("ValidateIP", "Validation", ErrorMessage = "Input is not a valid IP")]
Subclassed RemoteAttribute
/// <summary>
/// Custom Remote Attribute for Client an Server validation.
/// </summary>
public class CustomRemoteAttribute : RemoteAttribute
{
/// <summary>
/// List of all Controllers on MVC Application
/// </summary>
/// <returns></returns>
private static List<Type> GetControllerList()
{
return Assembly.GetCallingAssembly().GetTypes().Where(type => type.IsSubclassOf(typeof(Controller))).ToList();
}
/// <summary>
/// Constructor of base class.
/// </summary>
protected CustomRemoteAttribute()
{
}
/// <summary>
/// Constructor of base class.
/// </summary>
public CustomRemoteAttribute(string routeName)
: base(routeName)
{
}
/// <summary>
/// Constructor of base class.
/// </summary>
public CustomRemoteAttribute(string action, string controller)
: base(action, controller)
{
}
/// <summary>
/// Constructor of base class.
/// </summary>
public CustomRemoteAttribute(string action, string controller, string areaName)
: base(action, controller, areaName)
{
}
/// <summary>
/// Overridden IsValid function
/// </summary>
/// <param name="value"></param>
/// <param name="validationContext"></param>
/// <returns></returns>
protected override ValidationResult IsValid(object value, ValidationContext validationContext)
{
// Find the controller passed in constructor
var controller = GetControllerList().FirstOrDefault(x => x.Name == string.Format("{0}Controller", this.RouteData["controller"]));
if (controller == null)
{
// Default behavior of IsValid when no controller is found.
return ValidationResult.Success;
}
// Find the Method passed in constructor
var mi = controller.GetMethod(this.RouteData["action"].ToString());
if (mi == null)
{
// Default behavior of IsValid when action not found
return ValidationResult.Success;
}
// Create instance of the controller to be able to call non static validation method
var instance = Activator.CreateInstance(controller);
// invoke the method on the controller with value
var result = (JsonResult)mi.Invoke(instance, new object[] { value });
// Return success or the error message string from CustomRemoteAttribute
return (bool) result.Data ? ValidationResult.Success : new ValidationResult(base.ErrorMessageString);
}
}
Validation Controller Code
/// <summary>
/// Controller for Client and Server validation
/// <remarks>disable OutputCache</remarks>
/// </summary>
[OutputCache(Location = OutputCacheLocation.None, NoStore = true)]
public class ValidationController : Controller
{
/// <summary>
/// !!!!!!!!!!!!!!!!!! Needed for instance creation in custom attribute !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
/// </summary>
public ValidationController()
{
}
/// <summary>
/// IP regex pattern of my choice
/// </summary>
const string IpPattern = #"^(?:(?:25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)\.){3}(?:25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)$";
/// <summary>
/// MAC regex pattern of my choice
/// </summary>
const string MacPattern = "^([0-9A-F]{2}[:-]){5}([0-9A-F]{2})$";
/// <summary>
/// Validate IP
/// </summary>
/// <param name="ip">IP param is only submited on Serverside validation!!!</param>
/// <returns>Validation Result</returns>
public JsonResult ValidateIP(string ip)
{
// Check if ip and httpcontext is null to dodge NullReferenceException on Server side validation
if (string.IsNullOrEmpty(ip) && HttpContext == null)
{
return Json(false, JsonRequestBehavior.AllowGet);
}
/* Use IP on Serverside validation
* Use Querystring Param 0 to get IP from Client side vaildation without the need for the correct Id of input control */
string checkip = string.IsNullOrEmpty(ip) ? HttpContext.Request.QueryString[0] : ip;
if (string.IsNullOrEmpty(checkip))
{
return new JsonResult { Data = true, JsonRequestBehavior = JsonRequestBehavior.AllowGet };
}
return new JsonResult
{
Data = Regex.IsMatch(checkip, IpPattern),
JsonRequestBehavior = JsonRequestBehavior.AllowGet
};
}
}
This is the intended behavior of remote validation. There is no way to know what the implementation of IsValid would be so it simply returns true. If you want server side validation for the RemoteAttribute you should override IsValid just like you have done.
Remote validator often with an additional field. Here's the implementation for this case.
/// <summary>
/// Remote Attribute for Client an Server validation.
/// </summary>
public class RemoteWithServerSideAttribute : RemoteAttribute
{
/// <summary>
/// List of all Controllers on MVC Application
/// </summary>
/// <returns></returns>
private static IEnumerable<Type> GetControllerList()
{
return Assembly.GetCallingAssembly().GetTypes().Where( type => type.IsSubclassOf( typeof( Controller ) ) ).ToList();
}
/// <summary>
/// Constructor of base class.
/// </summary>
protected RemoteWithServerSideAttribute() {}
/// <summary>
/// Constructor of base class.
/// </summary>
public RemoteWithServerSideAttribute( string routeName ) : base( routeName ) {}
/// <summary>
/// Constructor of base class.
/// </summary>
public RemoteWithServerSideAttribute( string action, string controller ) : base( action, controller ){}
/// <summary>
/// Constructor of base class.
/// </summary>
public RemoteWithServerSideAttribute( string action, string controller, string areaName ) : base( action, controller, areaName ) {}
/// <summary>
/// Overridden IsValid function
/// </summary>
/// <param name="value"></param>
/// <param name="validationContext"></param>
/// <returns></returns>
protected override ValidationResult IsValid( object value, ValidationContext validationContext )
{
// Find the controller passed in constructor
var controller = GetControllerList().FirstOrDefault( x => x.Name == string.Format( "{0}Controller", this.RouteData["controller"] ) );
if ( controller == null )
{
// Default behavior of IsValid when no controller is found.
return ValidationResult.Success;
}
// Find the Method passed in constructor
var mi = controller.GetMethod( this.RouteData["action"].ToString() );
if ( mi == null )
{
// Default behavior of IsValid when action not found
return ValidationResult.Success;
}
// Create instance of the controller to be able to call non static validation method
var instance = Activator.CreateInstance( controller );
// invoke the method on the controller with value and "AdditionalFields"
JsonResult result;
if ( !string.IsNullOrWhiteSpace( AdditionalFields ) )
{
var additionalField = validationContext.ObjectType.GetProperty( AdditionalFields )
.GetValue( validationContext.ObjectInstance );
result = (JsonResult) mi.Invoke( instance, new [] { value, additionalField } );
}
else
result = (JsonResult)mi.Invoke( instance, new [] { value } );
// Return success or the error message string from CustomRemoteAttribute
string errorMessaqe = result.Data as string;
if (errorMessaqe == null)
{
bool isValid;
try
{
isValid = (bool) result.Data;
}
catch (Exception)
{
isValid = false;
}
return isValid ? ValidationResult.Success : new ValidationResult( base.ErrorMessageString );
}
else
return new ValidationResult( errorMessaqe );
}
}
As has been answered before, this is by design.
I have just stumbled upon a nice article on CodeProject - http://www.codeproject.com/Articles/361113/Extending-the-MVC-RemoteAttribute-to-validate-ser
The problem is that Remove Attribute requires Javascript validation, it does not work out of the box on the server-side... in other words, if you enable javascript validation, it will work and show the error(s), if you disable javascript and go to server validation, it will simply not show any errors on the modelstate, this is not a bug, its a feature hahaha... well, that's the way it was built (on ms)...
https://docs.devexpress.com/AspNet/17294/aspnet-mvc-extensions/data-editors-extensions/common-concepts/validation/remote-validation#requirements
If you need a remote validation attribute that works client and server side, you must create your own class inheriting RemoteAttribute, then you must deploy your own validation, check the following video: https://www.youtube.com/watch?v=qopOqppDwc4&t=110s
The video is almost correct, I did post a comment for controllers that use services via injection like dbcontext, etc... I did it and it works...