Query: Convert MaterializeCollectionNavigation to expression from met…

…hodCall For easier processing in the tree
dotnet · Jul 1, 2019 · d6da983 · d6da983
1 parent 9e3b10d
commit d6da983
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Showing 4 changed files with 54 additions and 33 deletions.
diff --git a/src/EFCore.Relational/Query/Pipeline/RelationalProjectionBindingExpressionVisitor.cs b/src/EFCore.Relational/Query/Pipeline/RelationalProjectionBindingExpressionVisitor.cs
@@ -95,16 +95,16 @@ public override Expression Visit(Expression expression)
                             Expression.Constant(parameterExpression.Name));
                     }
 
-                    if (expression is MethodCallExpression methodCallExpression)
+                    if (expression is MaterializeCollectionNavigationExpression materializeCollectionNavigationExpression)
                     {
-                        if (methodCallExpression.Method.Name == "MaterializeCollectionNavigation")
-                        {
-                            var result = _queryableMethodTranslatingExpressionVisitor.TranslateSubquery(methodCallExpression.Arguments[0]);
-                            var navigation = (INavigation)((ConstantExpression)methodCallExpression.Arguments[1]).Value;
-
-                            return _selectExpression.AddCollectionProjection(result, navigation, null);
-                        }
+                        return _selectExpression.AddCollectionProjection(
+                            _queryableMethodTranslatingExpressionVisitor.TranslateSubquery(
+                                materializeCollectionNavigationExpression.Subquery),
+                            materializeCollectionNavigationExpression.Navigation, null);
+                    }
 
+                    if (expression is MethodCallExpression methodCallExpression)
+                    {
                         if (methodCallExpression.Method.IsGenericMethod
                             && methodCallExpression.Method.DeclaringType == typeof(Enumerable)
                             && methodCallExpression.Method.Name == nameof(Enumerable.ToList))

diff --git a/src/EFCore/Query/NavigationExpansion/MaterializeCollectionNavigationExpression.cs b/src/EFCore/Query/NavigationExpansion/MaterializeCollectionNavigationExpression.cs
@@ -0,0 +1,45 @@
+// Copyright (c) .NET Foundation. All rights reserved.
+// Licensed under the Apache License, Version 2.0. See License.txt in the project root for license information.
+
+using System;
+using System.Linq.Expressions;
+using JetBrains.Annotations;
+using Microsoft.EntityFrameworkCore.Metadata;
+using Microsoft.EntityFrameworkCore.Query.Expressions.Internal;
+using Microsoft.EntityFrameworkCore.Query.Internal;
+
+namespace Microsoft.EntityFrameworkCore.Query.NavigationExpansion
+{
+    public class MaterializeCollectionNavigationExpression : Expression, IPrintable
+    {
+        public MaterializeCollectionNavigationExpression(Expression subquery, INavigation navigation)
+        {
+            Subquery = subquery;
+            Navigation = navigation;
+        }
+
+        public virtual Expression Subquery { get; }
+        public virtual INavigation Navigation { get; }
+
+        public override ExpressionType NodeType => ExpressionType.Extension;
+        public override Type Type => Navigation.ClrType;
+
+        public virtual void Print(ExpressionPrinter expressionPrinter)
+        {
+            expressionPrinter.StringBuilder.Append($"MaterializeCollectionNavigation({Navigation}, ");
+            expressionPrinter.Visit(Subquery);
+            expressionPrinter.StringBuilder.Append(")");
+        }
+
+        protected override Expression VisitChildren(ExpressionVisitor visitor)
+        {
+            var subquery = visitor.Visit(Subquery);
+
+            return subquery != Subquery
+                ? new MaterializeCollectionNavigationExpression(subquery, Navigation)
+                : this;
+        }
+
+
+    }
+}
diff --git a/src/EFCore/Query/NavigationExpansion/NavigationExpansionHelpers.cs b/src/EFCore/Query/NavigationExpansion/NavigationExpansionHelpers.cs
@@ -8,7 +8,6 @@
 using System.Reflection;
 using Microsoft.EntityFrameworkCore.Internal;
 using Microsoft.EntityFrameworkCore.Metadata;
-using Microsoft.EntityFrameworkCore.Metadata.Internal;
 using Microsoft.EntityFrameworkCore.Query.Expressions.Internal;
 using Microsoft.EntityFrameworkCore.Query.Internal;
 
@@ -276,19 +275,5 @@ public static Expression CreateNullKeyExpression(Type resultType, int keyCount)
                             Expression.Constant(null),
                             keyCount)))
                 : (Expression)Expression.Constant(null);
-
-        public static readonly MethodInfo MaterializeCollectionNavigationMethodInfo
-            = typeof(NavigationExpansionHelpers).GetTypeInfo()
-                .GetDeclaredMethod(nameof(MaterializeCollectionNavigation));
-
-        public static TResult MaterializeCollectionNavigation<TResult, TEntity>(
-            IEnumerable<object> elements,
-            INavigation navigation)
-            where TResult : IEnumerable<TEntity>
-        {
-            var collection = navigation.GetCollectionAccessor().Create(elements);
-
-            return (TResult)collection;
-        }
     }
 }
diff --git a/src/EFCore/Query/NavigationExpansion/Visitors/NavigationExpansionReducingVisitor.cs b/src/EFCore/Query/NavigationExpansion/Visitors/NavigationExpansionReducingVisitor.cs
@@ -83,16 +83,7 @@ protected override Expression VisitExtension(Expression extensionExpression)
 
                 if (state.MaterializeCollectionNavigation != null)
                 {
-                    var entityType = state.MaterializeCollectionNavigation.ClrType.IsGenericType
-                        ? state.MaterializeCollectionNavigation.ClrType.GetGenericArguments()[0]
-                        : state.MaterializeCollectionNavigation.GetTargetType().ClrType;
-
-                    result = Expression.Call(
-                        NavigationExpansionHelpers.MaterializeCollectionNavigationMethodInfo.MakeGenericMethod(
-                            state.MaterializeCollectionNavigation.ClrType,
-                            entityType),
-                        result,
-                        Expression.Constant(state.MaterializeCollectionNavigation));
+                    result = new MaterializeCollectionNavigationExpression(result, state.MaterializeCollectionNavigation);
                 }
 
                 if (navigationExpansionExpression.Type != result.Type && navigationExpansionExpression.Type.IsGenericType)