patterns & practices - Unity

New Post: Unity 3.0 registration troubles

PeterHowe — Mon, 17 Jun 2013 19:59:45 GMT

Thanks, Randy, that was it.

Actually, the TestAndDebugLoggingInterceptor is in a different namespace, but the problem was just what you said: it was not fully qualified. I did have the sectionExtension declaration in the app.config, but I missed the qualification on the TestAndDebugLoggingInterceptor. Thanks!

New Post: Unity 3.0 registration troubles

randylevy — Mon, 17 Jun 2013 19:28:34 GMT

You didn't post the full config so I'll mention that you need to add the sectionExtension:

<sectionExtension type="Microsoft.Practices.Unity.InterceptionExtension.Configuration.InterceptionConfigurationExtension, Microsoft.Practices.Unity.Interception.Configuration" />

Also, the type TestAndDebugLoggingInterceptor needs to be qualified unless an alias is created or the assembly and namespace search tags added to the config file.

The configuration should look something like this:


<?xml version="1.0" encoding="utf-8" ?>
<configuration>
  <configSections>
    <section name="unity" type="Microsoft.Practices.Unity.Configuration.UnityConfigurationSection, Microsoft.Practices.Unity.Configuration"/>
  </configSections>
  <unity xmlns="http://schemas.microsoft.com/practices/2010/unity">
<sectionExtension type="Microsoft.Practices.Unity.InterceptionExtension.Configuration.InterceptionConfigurationExtension, Microsoft.Practices.Unity.Interception.Configuration" />
    <container name="InterceptTestContainer">
      <extension type="Interception" />
      <register type="Paychex.IP.Common.TestObjects.TestClass, TestObjects" mapTo="Paychex.IP.Common.TestObjects.TestClass, TestObjects">
        <interceptor type="VirtualMethodInterceptor"/>
        <interceptionBehavior type="Paychex.IP.Common.TestObjects.TestAndDebugLoggingInterceptor, TestObjects" />
      </register>
    </container>    
  </unity>
</configuration>

~~
Randy Levy
entlib.support@live.com
Enterprise Library support engineer
Support How-to

New Post: Unity 3.0 registration troubles

PeterHowe — Mon, 17 Jun 2013 19:04:08 GMT

My bad, I said the parameter passed to container.LoadConfiguration was the type being intercepted, but it is actually the container name from the app.config file ("InterceptTestContainer.") It would seem that the code is finding that container name in the app.config file, but doesn't like the assemblies or paths being specified. The relevant section from the app.config file is:

<container name="InterceptTestContainer">
   <extension type="Interception" />
   <register type="Paychex.IP.Common.TestObjects.TestClass, TestObjects" mapTo="Paychex.IP.Common.TestObjects.TestClass, TestObjects">
      <interceptor type="VirtualMethodInterceptor"/>
      <interceptionBehavior type="TestAndDebugLoggingInterceptor" />
   </register>
</container>

Again, the syntax is based on what I have read in MSDN.

New Post: Unity 3.0 registration troubles

PeterHowe — Mon, 17 Jun 2013 18:14:17 GMT

Thanks in advance for your help...

I am struggling with Unity 3.0 trying to get types and interception registered correctly. The problem begins with Unity not liking the app.config file. Here is a snippet from a test program:

       try
        {
            container.LoadConfiguration(interceptedName);
        }
        catch (Exception ex)
        {
            Console.Write("Exception:"); // just so we can break and examine the exception
            Console.WriteLine(ex.Message);
            // This should not be necessary in Code!
            container.RegisterType<TestClass>(
                new Interceptor<VirtualMethodInterceptor>(),
                new InterceptionBehavior<TestAndDebugLoggingInterceptor>());
        }

"interceptedName" is equal to "TestAndDebugLoggingInterceptor." It throws an InvalidOperationException:

 The type name or alias 
      TestAndDebugLoggingInterceptor 
 could not be resolved. Please check your configuration file and verify this type name.

The call to container.RegisterType proceeds without an exception. However, when I trace through the code, the interceptor (TestAndDebugLoggingInterceptor) is registered twice, and it indeed calls it twice before calling the target method(s) in TestClass. At first, I thought that perhaps the registration from the app.config file was succeeding despite the exception. But, commenting out the call to container.RegisterType results in an exception that the type cannot be resolved.

I can post the app.config file if anyone wants to see it, but I am guessing at this point that it is not relevant, because of the exception being thrown. Aside from whatever syntax or path error there is in the app.config file, does anyone have any idea why RegisterType ends up wrapping the targets twice? The syntax for that call is straight out of MSDN examples, so I am somewhat stumped at this point.

Thanks again.

New Post: Resolving interface dependency in Unity 3.0

randylevy — Mon, 17 Jun 2013 13:41:55 GMT

Your code and configuration looks OK. I can inject a PersonDao interface into my controller.

Can you post a small sample project?

~~
Randy Levy
entlib.support@live.com
Enterprise Library support engineer
Support How-to

New Post: Resolving interface dependency in Unity 3.0

Netrider6 — Mon, 17 Jun 2013 13:06:01 GMT

I'm actually loading the configuration in another method; I didn't realize that UnityConfig did that for me. Still, I am loading the configuration. I have no problem injecting concrete classes (PersonDaoImpl); I only have problems if I try to inject a concrete implementation of an interface (PersonDaoImpl for a PersonDao).

Thanks...

New Post: Resolving interface dependency in Unity 3.0

randylevy — Mon, 17 Jun 2013 06:01:43 GMT

Did you uncomment the line in the RegisterType method of the App_Start/UnityConfig.cs file to load the configuration?

        /// <summary>Registers the type mappings with the Unity container.</summary>
        /// <param name="container">The unity container to configure.</param>
        /// <remarks>There is no need to register concrete types such as controllers or API controllers (unless you want to 
        /// change the defaults), as Unity allows resolving a concrete type even if it was not previously registered.</remarks>
        public static void RegisterTypes(IUnityContainer container)
        {
            // NOTE: To load from web.config uncomment the line below. Make sure to add a Microsoft.Practices.Unity.Configuration to the using statements.
            container.LoadConfiguration();

            // TODO: Register your types here
            // container.RegisterType<IProductRepository, ProductRepository>();
        }

~~
Randy Levy
entlib.support@live.com
Enterprise Library support engineer
Support How-to

New Post: Resolving interface dependency in Unity 3.0

Netrider6 — Sun, 16 Jun 2013 20:17:45 GMT

I'm trying to get dependency injection working on a MVC 4 web application using Unity 3.0. I have the Unity bootstrapper for MVC 4 applications installed, and I've set up my web.config file and Global.asax files to start up the Unity configuration. If I use concrete objects, it works without problems, but I start getting exceptions if I start to try to inject concrete implementations of interfaces instead.

For example, my PersonController looks like this:

namespace RebuildingSite.Controllers
{
    public class PersonController : Controller
    {
        private static readonly LogWriter log = LoggingFactory.GetLogWriter();

        [Dependency]
        public PersonDao ThePersonDao { get; set; }

        //
        // GET: /Person/
        public ActionResult Index(string sortOrder, string currentFilter, string searchString, int? page)
        {
            ViewBag.CurrentSort = sortOrder;
            ViewBag.NameSortParm = String.IsNullOrEmpty(sortOrder) ? "Name desc" : "";
            ViewBag.CitySortParm = sortOrder == "City" ? "City desc" : "City";

            if (Request.HttpMethod == "GET")
            {
                searchString = currentFilter;
            }
            else
            {
                page = 1;
            }

            ViewBag.CurrentFilter = searchString;

            page = page == null ? 1 : page;

            var people = ThePersonDao.GetPeopleByName(searchString, sortOrder, 10, (int)page);

            return View(people);
        }
}

And the Unity section of my web.config looks like this:

  <unity xmlns="http://schemas.microsoft.com/practices/2010/unity">
    <namespace name="RebuildingModel.Dao" />
    <namespace name="RebuildingModel.Dao.Impl" />
    <namespace name="RebuildingSite.Controllers" />
    
    <assembly name="RebuildingModel" />
    <assembly name="RebuildingSite" />
    
    <container>
      <register type="PersonDao" mapTo="PersonDaoImpl" />
      <register type="PersonController" mapTo="PersonController" />
    </container>
  </unity>

My PersonDaoImpl does implement PersonDao:

PersonDao:

namespace RebuildingModel.Dao
{
    public interface PersonDao : StandardDaoInterface<int, Person>
    {
        /// <summary>
        /// Search for a person by first or last name, sorting and sizing the resultant list as appropriate.
        /// </summary>
        /// <param name="name">Any search string that would be contained in the first or last name.</param>
        /// <param name="sort">The Person field on which to sort</param>
        /// <param name="pageSize">The size of the page</param>
        /// <param name="pageNumber">What page number is being returned</param>
        /// <returns>A list of people with a first or last name containing "name", sorted by "sort", 
        /// on "pageNumber" page number, with no more than "pageSize" people returned.</returns>
        IPagedList<Person> GetPeopleByName(string name, string sortOrder, int pageSize, int pageNumber);
    }
}

PersonDaoImpl:

namespace RebuildingModel.Dao.Impl
{
    public class PersonDaoImpl : PersonDao
    {
        private static readonly LogWriter log = LoggingFactory.GetLogWriter();

        public PersonDaoImpl()
        {
        }

        public PagedList.IPagedList<Person> GetPeopleByName(string name, string sortOrder, int pageSize, int pageNumber)
        {
            log.Write("Searching for person name containing " + name + " sorting by " + sortOrder +
                      " page size " + pageSize + ", page number " + pageNumber);

            using (var db = new RebuildingTogetherEntities())
            {
                var people = from p in db.People
                             select p;

                if (!String.IsNullOrEmpty(name))
                {
                    people = people.Where( p => p.LastName.ToUpper().Contains(name) ||
                                                p.FirstName.ToUpper().Contains(name) );
                }

                switch (sortOrder)
                {
                    case "Name desc":
                        people = people.OrderByDescending(p => p.LastName);
                        break;
                    case "City desc":
                        people = people.OrderByDescending(p => p.City);
                        break;
                    case "City":
                        people = people.OrderBy(p => p.City);
                        break;
                    default:
                        people = people.OrderBy(p => p.LastName);
                        break;
                }

                return people.ToPagedList(pageNumber, pageSize);
            }
        }
}

But, when I start the app, I get this error:

6/16/2013 3:02:07 PM|System.InvalidOperationException: An error occurred when trying to create a controller of type 'RebuildingSite.Controllers.PersonController'. Make sure that the controller has a parameterless public constructor. ---> Microsoft.Practices.Unity.ResolutionFailedException: Resolution of the dependency failed, type = "RebuildingSite.Controllers.PersonController", name = "(none)".
Exception occurred while: while resolving.
Exception is: InvalidOperationException - The type PersonDao does not have an accessible constructor.
-----------------------------------------------
At the time of the exception, the container was:

  Resolving RebuildingSite.Controllers.PersonController,(none)
  Resolving value for property PersonController.ThePersonDao
    Resolving RebuildingModel.Dao.PersonDao,(none)
 ---> System.InvalidOperationException: The type PersonDao does not have an accessible constructor.
   at Microsoft.Practices.ObjectBuilder2.DynamicMethodConstructorStrategy.ThrowForNullExistingObject(IBuilderContext context)
   at lambda_method(Closure , IBuilderContext )
   at Microsoft.Practices.ObjectBuilder2.DynamicBuildPlanGenerationContext.<>c__DisplayClass1.<GetBuildMethod>b__0(IBuilderContext context)
   at Microsoft.Practices.ObjectBuilder2.DynamicMethodBuildPlan.BuildUp(IBuilderContext context)
...

How do I inject an implementation of PersonDao rather than a concrete class like PersonDaoImpl?

Thanks!

New Post: Unit3 LoadConfiguration() deprecated?

homelchenko — Sun, 16 Jun 2013 15:24:53 GMT

You're welcome, and tools like Resharper and others would have helped you, they do suggest such modifications

New Post: Unit3 LoadConfiguration() deprecated?

Netrider6 — Sun, 16 Jun 2013 14:34:52 GMT

D'oh! That was simple! Thanks homelchenko, it works now. I wish VS would suggest using statements for extension methods...

New Post: Unit3 LoadConfiguration() deprecated?

homelchenko — Sun, 16 Jun 2013 08:27:51 GMT

Please, make sure there is a 'using Microsoft.Practices.Unity.Configuration;' wherever you're going to use that extension method.

New Post: Unit3 LoadConfiguration() deprecated?

Netrider6 — Sat, 15 Jun 2013 22:10:33 GMT

If it makes any difference, I'm using Visual Studio 2012 Express.

New Post: Unit3 LoadConfiguration() deprecated?

Netrider6 — Sat, 15 Jun 2013 21:30:05 GMT

I do see the reference to Microsoft.Practices.Unity.Configuration in the references section, but the compilation still fails. I tried uninstalling and reinstalling the Unity package from NuGet, and also tried adding an assembly reference by browsing. I still can't get the thing to compile.

I'd upload a screenshot if there were an easy way to do so...

New Post: Unit3 LoadConfiguration() deprecated?

randylevy — Sat, 15 Jun 2013 21:18:29 GMT

It should be downloaded from NuGet. The assembly is in the packages\Unity.3.0.1304.0\lib\Net45\ directory. It should be added to the project's References automatically.

~~
Randy Levy
entlib.support@live.com
Enterprise Library support engineer
Support How-to

New Post: Unit3 LoadConfiguration() deprecated?

Netrider6 — Sat, 15 Jun 2013 21:07:49 GMT

That assembly doesn't seem to be present; I installed the Unity Framework with NuGet... do I need to get something else too?

Thanks

New Post: Unit3 LoadConfiguration() deprecated?

randylevy — Sat, 15 Jun 2013 21:00:23 GMT

The LoadConfiguration is an extension method in the Microsoft.Practices.Unity.Configuration assembly. You need to add a reference to Microsoft.Practices.Unity.Configuration.dll.

~~
Randy Levy
entlib.support@live.com
Enterprise Library support engineer
Support How-to

New Post: Unit3 LoadConfiguration() deprecated?

Netrider6 — Sat, 15 Jun 2013 20:40:52 GMT

I am new to Unity (version 3.0.1304.0) and am trying to set up my first web application with dependency injection. I have a web.config file that looks like this:

<?xml version="1.0" encoding="utf-8"?>
<!--
  For more information on how to configure your ASP.NET application, please visit
  http://go.microsoft.com/fwlink/?LinkId=169433
  -->
<configuration>
  <configSections>
    <section name="unity" type="Microsoft.Practices.Unity.Configuration.UnityConfigurationSection, Microsoft.Practices.Unity.Configuration"/>
  </configSections>
<!--Irrelevant stuff omitted-->
  <unity xmlns="http://schemas.microsoft.com/practices/2010/unity">
    <alias alias="ILogger" type="MyApp.ILogger, MyApp" />
    <namespace name="MyApp.Implementations" />
    <assembly name="MyApp" />
    
    <container>
      <register type="ILogger" name="special" mapTo="SpecialLogger" />    
    </container>
  </unity>

</configuration>

From the documentation, it says, "Adding a Unity configuration section to a configuration file neither create an actual container nor configures it. You must create a Unity container instance, read the configuration file, and load the configuration file information into the container. "

But the code it references:

IUnityContainer container = new UnityContainer();

container.LoadConfiguration();

seems to be incorrect...

Error   14  'Microsoft.Practices.Unity.UnityContainer' does not contain a definition for 'LoadConfiguration' and no extension method 'LoadConfiguration' accepting a first argument of type 'Microsoft.Practices.Unity.UnityContainer' could be found (are you missing a using directive or an assembly reference?) C:\Users\Brad\Documents\Visual Studio 2012\Projects\RebuildingSite\RebuildingSite\Global.asax.cs    34  23  RebuildingSite

Am I doing something wrong, or do I not need that method anymore?

New Post: ASP.NET Web API - Inject Dependencies Into ActionFilterAttribute

randylevy — Fri, 14 Jun 2013 18:53:11 GMT

Sorry, my post was about ASP.NET MVC and not ASP.NET Web API. Oops, my bad.

What version of ASP.NET MVC are you using? I'm using version 4.

Also, based on your code sample it looks like you may be using another NuGet package? Perhaps Unity.Mvc4 or Unity.MVC3?

When I install the official Unity bootstrapper for ASP.NET Web API two files are added to App_Start: UnityConfig.cs and UnityWebApiActivator.cs.

To get injection working for an instance of System.Web.Http.Filters.ActionFilterAttribute I had to create a custom IFilterProvider. To do this I extended ActionFilterDescriptorFilterProvider:

    public class UnityActionFilterProvider : ActionDescriptorFilterProvider, IFilterProvider
    {
        private readonly IUnityContainer container;

        public UnityActionFilterProvider(IUnityContainer container)
        {
            this.container = container;
        }

        public new IEnumerable<FilterInfo> GetFilters(HttpConfiguration configuration, HttpActionDescriptor actionDescriptor)
        {
            var filters = base.GetFilters(configuration, actionDescriptor);
            List<FilterInfo> filterInfoList = new List<FilterInfo>();

            foreach (var filter in filters)
            {
                container.BuildUp(filter.Instance.GetType(), filter.Instance);
            }

            return filters;
        }
    }

Next I created a helper method, RegisterFilterProviders, to register the provider:

    public static void RegisterFilterProviders()
    {
        var providers = GlobalConfiguration.Configuration.Services.GetFilterProviders().ToList();
        GlobalConfiguration.Configuration.Services.Add(typeof(System.Web.Http.Filters.IFilterProvider),
                                                        new UnityActionFilterProvider(UnityConfig.GetConfiguredContainer()));

        var defaultprovider = providers.First(p => p is ActionDescriptorFilterProvider);
        GlobalConfiguration.Configuration.Services.Remove(typeof(System.Web.Http.Filters.IFilterProvider), defaultprovider);
    }

The above method can be called from within Application_Start in Global.asax or some other place during Unity bootstrapping.

Once that is set up, the System.Web.Http.Filters.ActionFilterAttribute has it's properties injected.

~~
Randy Levy
entlib.support@live.com
Enterprise Library support engineer
Support How-to

New Post: ASP.NET Web API - Inject Dependencies Into ActionFilterAttribute

Sohnee — Fri, 14 Jun 2013 09:39:57 GMT

All of the types are registered correctly - they are used by many of the controllers and that all works. It doesn't work for the filter attributes though.

As a potentially interesting side note, Unity added Bootstrapper.cs to the root folder, but not UnityConfig or UnityMvcActivator in the app_start. Maybe this is because I installed the Web API Nuget package?

    public static class Bootstrapper
    {
        public static void Initialise()
        {
            var container = BuildUnityContainer();

            GlobalConfiguration.Configuration.DependencyResolver = new Unity.WebApi.UnityDependencyResolver(container);
        }

        private static IUnityContainer BuildUnityContainer()
        {
            var container = new UnityContainer();

            container.RegisterType<IApiUserService, ApiUserService>();
            // Others...

            return container;
        }
    }

New Post: ASP.NET Web API - Inject Dependencies Into ActionFilterAttribute

Sohnee — Fri, 14 Jun 2013 09:39:57 GMT

    public static class Bootstrapper
    {
        public static void Initialise()
        {
            var container = BuildUnityContainer();

            GlobalConfiguration.Configuration.DependencyResolver = new Unity.WebApi.UnityDependencyResolver(container);
        }

        private static IUnityContainer BuildUnityContainer()
        {
            var container = new UnityContainer();

            container.RegisterType<IApiUserService, ApiUserService>();
            // Others...

            return container;
        }
    }