Databases
StackOverflow2013
Postsdbo
PO
 

Note that there are some explanatory texts on larger screens.

plurals
  1. PO
    primarykey
    data
    text
    <p>I don't like to answer my own questions, but I was able to somehow solve the problem and I believe the solution is good enough that others may be interested. I looked at Unity's source code and got the basic idea from there. I also read a couple of posts regarding Unity. Here it is:</p> <p>First, I had to create a class that inherited from <code>IBuildPlanPolicy</code>. It is long because I left some supporting classes within the class itself:</p> <pre><code> public class AutomaticFactoryBuilderPolicy : IBuildPlanPolicy { private readonly Dictionary&lt;Type, Type&gt; _callables = new Dictionary&lt;Type, Type&gt; { {typeof(Func&lt;,&gt;), typeof(CallableType&lt;,&gt;)}, {typeof(Func&lt;,,&gt;), typeof(CallableType&lt;,,&gt;)}, {typeof(Func&lt;,,,&gt;), typeof(CallableType&lt;,,,&gt;)}, {typeof(Func&lt;,,,,&gt;), typeof(CallableType&lt;,,,,&gt;)} }; public void BuildUp(IBuilderContext context) { if (context.Existing == null) { var currentContainer = context.NewBuildUp&lt;IUnityContainer&gt;(); var buildKey = context.BuildKey; string nameToBuild = buildKey.Name; context.Existing = CreateResolver(currentContainer, buildKey.Type, nameToBuild); } } private Delegate CreateResolver(IUnityContainer currentContainer, Type typeToBuild, string nameToBuild) { Type[] delegateTypes = typeToBuild.GetGenericArguments(); Type func = typeToBuild.GetGenericTypeDefinition(); Type callable = _callables[func]; Type callableType = callable.MakeGenericType(delegateTypes); Type delegateType = func.MakeGenericType(delegateTypes); MethodInfo resolveMethod = callableType.GetMethod("Resolve"); object callableObject = Activator.CreateInstance(callableType, currentContainer, nameToBuild); return Delegate.CreateDelegate(delegateType, callableObject, resolveMethod); } private class CallableType&lt;T1, TResult&gt; { private readonly IUnityContainer _container; private readonly string _name; public CallableType(IUnityContainer container, string name) { _container = container; _name = name; } public TResult Resolve(T1 p1) { return _container.Resolve&lt;TResult&gt;(_name, new OrderedParametersOverride(new object[] { p1 })); } } private class CallableType&lt;T1, T2, TResult&gt; { private readonly IUnityContainer _container; private readonly string _name; public CallableType(IUnityContainer container, string name) { _container = container; _name = name; } public TResult Resolve(T1 p1, T2 p2) { return _container.Resolve&lt;TResult&gt;(_name, new OrderedParametersOverride(new object[] { p1, p2 })); } } private class CallableType&lt;T1, T2, T3, TResult&gt; { private readonly IUnityContainer _container; private readonly string _name; public CallableType(IUnityContainer container, string name) { _container = container; _name = name; } public TResult Resolve(T1 p1, T2 p2, T3 p3) { return _container.Resolve&lt;TResult&gt;(_name, new OrderedParametersOverride(new object[] { p1, p2, p3 })); } } private class CallableType&lt;T1, T2, T3, T4, TResult&gt; { private readonly IUnityContainer _container; private readonly string _name; public CallableType(IUnityContainer container, string name) { _container = container; _name = name; } public TResult Resolve(T1 p1, T2 p2, T3 p3, T4 p4) { return _container.Resolve&lt;TResult&gt;(_name, new OrderedParametersResolverOverride(new object[] { p1, p2, p3, p4 })); } } } </code></pre> <p>It is pretty straightforward. The trick is to create one <code>CallableType</code> for each <code>Func</code> I want to handle. It is not as dynamic as I first wanted, but in order to make it more dynamic I believe I would have to deal with either IL or Expression Trees. The way I have it now is good enough for me.</p> <p>Second, Unity handles parameters by name but I had to deal with them by order. That's where OrderedParametersResolverOverride comes into play (this class is used in the code above. Check <code>CallableType</code> classes):</p> <pre><code>public class OrderedParametersResolverOverride : ResolverOverride { private readonly Queue&lt;InjectionParameterValue&gt; _parameterValues; public OrderedParametersResolverOverride(IEnumerable&lt;object&gt; parameterValues) { _parameterValues = new Queue&lt;InjectionParameterValue&gt;(); foreach (var parameterValue in parameterValues) { _parameterValues.Enqueue(InjectionParameterValue.ToParameter(parameterValue)); } } public override IDependencyResolverPolicy GetResolver(IBuilderContext context, Type dependencyType) { if (_parameterValues.Count &lt; 1) return null; var value = _parameterValues.Dequeue(); return value.GetResolverPolicy(dependencyType); } } </code></pre> <p>Those two classes deal with <code>Func</code> creation. The next step is to add that builder to Unity's pipeline. We'll need to create a UnityContainerExtension:</p> <pre><code>public class AutomaticFactoryExtension: UnityContainerExtension { protected override void Initialize() { var automaticFactoryBuilderPolicy = new AutomaticFactoryBuilderPolicy(); Context.Policies.Set(typeof(Microsoft.Practices.ObjectBuilder2.IBuildPlanPolicy), automaticFactoryBuilderPolicy, new Microsoft.Practices.ObjectBuilder2.NamedTypeBuildKey(typeof(Func&lt;,&gt;))); Context.Policies.Set(typeof(Microsoft.Practices.ObjectBuilder2.IBuildPlanPolicy), automaticFactoryBuilderPolicy, new Microsoft.Practices.ObjectBuilder2.NamedTypeBuildKey(typeof(Func&lt;,,&gt;))); Context.Policies.Set(typeof(Microsoft.Practices.ObjectBuilder2.IBuildPlanPolicy), automaticFactoryBuilderPolicy, new Microsoft.Practices.ObjectBuilder2.NamedTypeBuildKey(typeof(Func&lt;,,,&gt;))); Context.Policies.Set(typeof(Microsoft.Practices.ObjectBuilder2.IBuildPlanPolicy), automaticFactoryBuilderPolicy, new Microsoft.Practices.ObjectBuilder2.NamedTypeBuildKey(typeof(Func&lt;,,,,&gt;))); } } </code></pre> <p>The last piece is to actually add that class to Unity's pipeline:</p> <pre><code>IUnityContainer container = new UnityContainer(); container.AddExtension(new AutomaticFactoryExtension()); </code></pre> <p>The rest of the registration is standard.</p> <p>Now it is possible to have constructors from <code>Func&lt;&gt;</code> to <code>Fun&lt;,,,,&gt;</code>. The following constructor, for instance, is now handled (assuming it is possible to resolve <code>IFoo</code>):</p> <pre><code>public class Bar { private readonly Func&lt;int, string, IFoo&gt; _fooFactory; public Bar(Func&lt;int, string, IFoo&gt; fooFactory) { _fooFactory = fooFactory; } } </code></pre> <p>Let me know if there are any question.</p> <p>Hope this helps.</p>
    singulars
    1. This table or related slice is empty.
    1. POUnity's automatic abstract factory
      singulars
      1. PTQuestion
    1. PTAnswer
    1. USM.Stramm
    1. USAllan
    plurals
    1. This table or related slice is empty.
    1. This table or related slice is empty.
    1. This table or related slice is empty.
    1. This table or related slice is empty.
    1. VO
      singulars
      1. PO
      1. This table or related slice is empty.
      1. VTUpMod
    1. COThat's a good solution, but do note that it obviously requires a specific ctor to be chosen by unity that matches the signature of the Func and if they don't match you'll get errors at runtime. Also keep in mind that InjectionParameterValue.ToParameter will change Type instances into requests to resolve dependencies. So if you need to pass a Type as a ctor parameter you will need to wrap it into an InjectionParameter<Type> and that should be in the signature of the func you resolve.
      singulars
      1. PO
      1. USfsimonazzi
    2. COYes, I understand the constructor limitation. But it is good enough to solve my problem. i didn't know about the Type limitation. I do not need to use type as constructors arguments (so far). Anyway, would you have any code example (end to end) to deal with that?
      singulars
      1. PO
      1. USAllan
    3. COIf you had this: public interface IFoo { void DoSomething(); } public class Bar : IFoo { private int theInt; private Type theType; public Bar(int theInt, Type theType) { this.theInt = theInt; this.theType = theType; } public void DoSomething() { Console.WriteLine(this.theInt + " " + this.theType.Name); } }
      singulars
      1. PO
      1. USfsimonazzi
 

Querying!

 
Guidance
A row detail

Detail views are divided into sections. All the information in the data section comes from columns in the selected row. The other sections display data from other, related rows.

Related data can be related in a to-one or a to-many fashion. Captions of data related in a to-many fashion link to a list view showing a filtered view of the table.

Try moving around until you find a non-empty to-many entry and click on the label to get to one. You can move back to the root by clicking on the database name in the header.

SQuiL has stopped working due to an internal error.

If you are curious you may find further information in the browser console, which is accessible through the devtools (F12).

Reload