Added support to retrieve EDM model by API version

Author: Chris Martinez

src/Microsoft.AspNet.OData.Versioning/System.Web.Http/HttpConfigurationExtensions.cs

@@ -768,5 +768,52 @@ static IContainerBuilder CreateContainerBuilderWithDefaultServices( this HttpCon
 
             return builder;
         }
+
+        /// <summary>
+        /// Gets the configured entity data model (EDM) for the specified API version.
+        /// </summary>
+        /// <param name="configuration">The server configuration.</param>
+        /// <param name="apiVersion">The <see cref="ApiVersion">API version</see> to get the model for.</param>
+        /// <returns>The matching <see cref="IEdmModel">EDM model</see> or <c>null</c>.</returns>
+        public static IEdmModel GetEdmModel( this HttpConfiguration configuration, ApiVersion apiVersion )
+        {
+            Arg.NotNull( configuration, nameof( configuration ) );
+            Arg.NotNull( apiVersion, nameof( apiVersion ) );
+
+            var allRoutes = configuration.Routes;
+            var routes = new KeyValuePair<string, IHttpRoute>[allRoutes.Count];
+            var containers = configuration.GetRootContainerMappings();
+
+            allRoutes.CopyTo( routes, 0 );
+
+            foreach ( var route in routes )
+            {
+                if ( !( route.Value is ODataRoute odataRoute ) )
+                {
+                    continue;
+                }
+
+                if ( !containers.TryGetValue( route.Key, out var serviceProvider ) )
+                {
+                    continue;
+                }
+
+                var model = serviceProvider.GetService<IEdmModel>();
+
+                if ( model?.EntityContainer == null )
+                {
+                    continue;
+                }
+
+                var modelApiVersion = model.GetAnnotationValue<ApiVersionAnnotation>( model )?.ApiVersion;
+
+                if ( modelApiVersion == apiVersion )
+                {
+                    return model;
+                }
+            }
+
+            return null;
+        }
     }
 }

src/Microsoft.AspNet.OData.Versioning/System.Web.Http/IContainerBuilderExtensions.cs

@@ -12,7 +12,7 @@
     using System.Web.OData.Routing.Conventions;
     using static Microsoft.OData.ServiceLifetime;
 
-    internal static class IContainerBuilderExtensions
+    static class IContainerBuilderExtensions
     {
         internal static void InitializeAttributeRouting( this IServiceProvider serviceProvider ) => serviceProvider.GetServices<IODataRoutingConvention>();
 

test/Microsoft.AspNet.OData.Versioning.Tests/System.Web.OData/HttpConfigurationExtensionsTest.cs

@@ -96,6 +96,25 @@ public void map_versioned_odata_routes_should_return_expected_results()
             batchRoute.RouteTemplate.Should().Be( "api/$batch" );
         }
 
+        [Theory]
+        [InlineData( 0, "1.0" )]
+        [InlineData( 1, "2.0" )]
+        public void get_edm_model_should_retrieve_configured_model_by_api_version( int modelIndex, string apiVersionValue )
+        {
+            // arrange
+            var apiVersion = ApiVersion.Parse( apiVersionValue );
+            var configuration = new HttpConfiguration();
+            var models = CreateModels( configuration ).ToArray();
+
+            configuration.MapVersionedODataRoutes( "odata", "api", models );
+
+            // act
+            var model = configuration.GetEdmModel( apiVersion );
+
+            // assert
+            model.Should().BeSameAs( models[modelIndex] );
+        }
+
         static IEnumerable<IEdmModel> CreateModels( HttpConfiguration configuration )
         {
             var controllerTypeResolver = new Mock<IHttpControllerTypeResolver>();