Introduced interface for DbContext.

References #19

src/Microsoft.Restier.EntityFramework/EntityFrameworkApi.cs

@@ -28,7 +28,7 @@ namespace Microsoft.Restier.EntityFramework
 #if EF7
     [CLSCompliant(false)]
 #endif
-    public class EntityFrameworkApi<T> : ApiBase where T : DbContext
+    public class EntityFrameworkApi<T> : ApiBase, IDbContextProvider where T : DbContext
     {
         /// <summary>
         /// Initializes a new instance of the <see cref="EntityFrameworkApi{T}" /> class.
@@ -43,14 +43,19 @@ public EntityFrameworkApi(IServiceProvider serviceProvider) : base(serviceProvid
         /// <summary>
         /// Gets the underlying DbContext for this API.
         /// </summary>
-        protected T DbContext
+        protected virtual T DbContext
         {
             get
             {
                 return (T)this.GetApiService<DbContext>();
             }
         }
 
+        /// <summary>
+        /// Gets the underlying DbContext for this API.
+        /// </summary>
+        DbContext IDbContextProvider.DbContext => DbContext;
+
 
         /// <summary>
         /// Configures the API services for this API. Descendants may override this method to register

src/Microsoft.Restier.EntityFramework/IDbContextProvider.cs

@@ -0,0 +1,20 @@
+using System;
+using System.Collections.Generic;
+using System.Data.Entity;
+using System.Linq;
+using System.Text;
+using System.Threading.Tasks;
+
+namespace Microsoft.Restier.EntityFramework
+{
+    /// <summary>
+    /// Interface to implement by Api classes to get the context.
+    /// </summary>
+    public interface IDbContextProvider
+    {
+        /// <summary>
+        /// Gets the underlying DbContext for this API.
+        /// </summary>
+        DbContext DbContext { get; }
+    }
+}

src/Microsoft.Restier.EntityFramework/Model/ModelProducer.cs

@@ -47,8 +47,8 @@ public Task<IEdmModel> GetModelAsync(ModelContext context, CancellationToken can
         {
             Ensure.NotNull(context, nameof(context));
 
+            var dbContext = (context.Api as IDbContextProvider).DbContext;
 #if EF7
-            var dbContext = context.GetApiService<DbContext>();
             context.ResourceSetTypeMap.AddRange(dbContext.GetType().GetProperties()
                 .Where(e => e.PropertyType.FindGenericType(typeof(DbSet<>)) != null)
                 .ToDictionary(e => e.Name, e => e.PropertyType.GetGenericArguments()[0]));
@@ -57,8 +57,7 @@ public Task<IEdmModel> GetModelAsync(ModelContext context, CancellationToken can
                 e => ((ICollection<PropertyInfo>)
                     e.FindPrimaryKey().Properties.Select(p => e.ClrType.GetProperty(p.Name)).ToList())));
 #else
-            var dbContext = context.GetApiService<DbContext>();
-
+
             var efModel = (dbContext as IObjectContextAdapter).ObjectContext.MetadataWorkspace;
 
             // @robertmclaws: The query below actually returns all registered Containers

src/Microsoft.Restier.EntityFramework/Query/QueryExpressionSourcer.cs

@@ -42,7 +42,7 @@ public Expression ReplaceQueryableSource(QueryExpressionContext context, bool em
                 return null;
             }
 
-            var dbContext = context.QueryContext.GetApiService<DbContext>();
+            var dbContext = (context.QueryContext.Api as IDbContextProvider).DbContext;
             var dbSetProperty = dbContext.GetType().GetProperties()
                 .FirstOrDefault(prop => prop.Name == context.ModelReference.EntitySet.Name);
             if (dbSetProperty == null)

src/Microsoft.Restier.EntityFramework/Submit/ChangeSetInitializer.cs

@@ -38,7 +38,7 @@ public async Task InitializeAsync(SubmitContext context, CancellationToken cance
                 throw new ArgumentNullException(nameof(context));
             }
 
-            var dbContext = context.GetApiService<DbContext>();
+            var dbContext = (context.Api as IDbContextProvider).DbContext;
 
             foreach (var entry in context.ChangeSet.Entries.OfType<DataModificationItem>())
             {

src/Microsoft.Restier.EntityFramework/Submit/SubmitExecutor.cs

@@ -27,7 +27,7 @@ internal class SubmitExecutor : ISubmitExecutor
         /// <returns>The task object that represents this asynchronous operation.</returns>
         public async Task<SubmitResult> ExecuteSubmitAsync(SubmitContext context, CancellationToken cancellationToken)
         {
-            var dbContext = context.GetApiService<DbContext>();
+            var dbContext = (context.Api as IDbContextProvider).DbContext;
             await dbContext.SaveChangesAsync(cancellationToken).ConfigureAwait(false);
             return new SubmitResult(context.ChangeSet);
         }