ensure we resolve concrete types

dansiegel · Jun 29, 2020 · 4c4ea40 · 4c4ea40
1 parent 92be064
commit 4c4ea40
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Showing 3 changed files with 41 additions and 4 deletions.
diff --git a/src/Prism.Microsoft.DependencyInjection.Extensions/MicrsoftDependencyInjectionExtensions.cs b/src/Prism.Microsoft.DependencyInjection.Extensions/MicrsoftDependencyInjectionExtensions.cs
@@ -1,4 +1,5 @@
 using System;
+using System.Linq;
 using System.Runtime.CompilerServices;
 using Microsoft.Extensions.DependencyInjection;
 using Prism.Ioc;
@@ -19,5 +20,28 @@ public static IServiceCollection ServiceCollection(this IContainerRegistry conta
 
             throw new NotImplementedException("IContainerRegistry must be implmented from the concrete type PrismContainerExtension");
         }
+
+        internal static object GetOrConstructService(this IServiceProvider provider, Type type, params (Type Type, object Instance)[] parameters)
+        {
+            var instance = provider.GetService(type);
+            if (instance is null && !type.IsInterface && !type.IsAbstract)
+            {
+                var ctor = type.GetConstructors().OrderByDescending(x => x.GetParameters().Length).FirstOrDefault();
+                if (ctor is null)
+                    throw new NullReferenceException($"Could not locate a public constructor for {type.FullName}");
+
+                var ctorParameters = ctor.GetParameters();
+                var args = ctor.GetParameters().Select(x =>
+                {
+                    object arg = parameters.FirstOrDefault(p => x.ParameterType.IsAssignableFrom(p.Instance.GetType())).Instance;
+                    if (arg != null)
+                        return arg;
+
+                    return provider.GetService(x.ParameterType);
+                });
+                return ctor.Invoke(args.ToArray());
+            }
+            return instance;
+        }
     }
 }
diff --git a/src/Prism.Microsoft.DependencyInjection.Extensions/NamedServiceRegistry.cs b/src/Prism.Microsoft.DependencyInjection.Extensions/NamedServiceRegistry.cs
@@ -53,6 +53,11 @@ public object GetService(IServiceProvider serviceProvider, string name, Type typ
             return registry?.GetService(serviceProvider);
         }
 
+        public Type GetRegistrationType(string key)
+        {
+            return Services.FirstOrDefault(x => x.Name.Equals(key, StringComparison.OrdinalIgnoreCase) || x.ImplementationType.Name.Equals(key, StringComparison.OrdinalIgnoreCase))?.ImplementationType;
+        }
+
         private void CheckDuplicate(string name, Type serviceType)
         {
             var registry = GetServiceRegistry(name, serviceType);
@@ -73,7 +78,7 @@ class NamedService
             public Type ImplementationType { get; set; }
 
             public virtual object GetService(IServiceProvider serviceProvider) =>
-                serviceProvider.GetService(ImplementationType);
+                serviceProvider.GetOrConstructService(ImplementationType);
         }
 
         class NamedSingletonService : NamedService
@@ -84,7 +89,7 @@ public override object GetService(IServiceProvider serviceProvider)
             {
                 if(Instance is null)
                 {
-                    Instance = serviceProvider.GetService(ImplementationType);
+                    Instance = serviceProvider.GetOrConstructService(ImplementationType);
                 }
 
                 return Instance;

diff --git a/src/Prism.Microsoft.DependencyInjection.Extensions/PrismContainerExtension.cs b/src/Prism.Microsoft.DependencyInjection.Extensions/PrismContainerExtension.cs
@@ -123,8 +123,16 @@ public object Resolve(Type type, string name) =>
 
         public object Resolve(Type type, params (Type Type, object Instance)[] parameters)
         {
-            var provider = parameters.Length > 0 ? GetChildProvider(parameters) : Instance;
-            return provider.GetService(type) ?? throw NullResolutionException(type);
+            try
+            {
+                var provider = parameters.Length > 0 ? GetChildProvider(parameters) : Instance;
+
+                return provider.GetOrConstructService(type, parameters) ?? throw NullResolutionException(type);
+            }
+            catch (Exception ex)
+            {
+                throw new ContainerResolutionException(type, ex);
+            }
         }
 
         public object Resolve(Type type, string name, params (Type Type, object Instance)[] parameters)