Dependency Injection extensions

SystemExtensions.NetStandard.DependencyInjection/Http/HttpClientResolver.cs

@@ -0,0 +1,47 @@
+using Slim.Resolvers;
+using System.Linq;
+using System.Net.Http;
+
+namespace System.Http
+{
+    public sealed class HttpClientResolver : IDependencyResolver
+    {
+        private static readonly Type clientType = typeof(HttpClient<>);
+
+        /// <summary>
+        /// Factory method. <see cref="Type"/> parameter of the factory is the scope of <see cref="IHttpClient{TScope}"/>.
+        /// </summary>
+        public Func<Slim.IServiceProvider, Type, HttpMessageHandler> HttpMessageHandlerFactory { get; set; }
+
+        /// <summary>
+        /// Sets the <see cref="HttpMessageHandlerFactory"/>.
+        /// </summary>
+        /// <param name="factory">Factory method. <see cref="Type"/> parameter of the factory is the scope of <see cref="IHttpClient{TScope}"/>.</param>
+        /// <returns></returns>
+        public HttpClientResolver WithHttpMessageHandlerFactory(Func<Slim.IServiceProvider, Type, HttpMessageHandler> factory)
+        {
+            this.HttpMessageHandlerFactory = factory;
+            return this;
+        }
+
+        public bool CanResolve(Type type)
+        {
+            if (type.IsGenericType && type.GetGenericTypeDefinition() == typeof(IHttpClient<>))
+            {
+                return true;
+            }
+
+            return false;
+        }
+
+        public object Resolve(Slim.IServiceProvider serviceProvider, Type type)
+        {
+            var typedClientType = clientType.MakeGenericType(type.GetGenericArguments());
+            var handler = this.HttpMessageHandlerFactory?.Invoke(serviceProvider, type.GetGenericArguments().First());
+            var httpClient = handler is null ?
+                Activator.CreateInstance(typedClientType) :
+                Activator.CreateInstance(typedClientType, new object[] { handler });
+            return httpClient;
+        }
+    }
+}