Implement 1:1 relations delete behavior setting and restriction to th…

…e dependent side
Vekz · May 15, 2022 · 8d9d189 · 8d9d189
1 parent 5357529
commit 8d9d189
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Showing 2 changed files with 68 additions and 1 deletion.
diff --git a/src/EFCore/Metadata/Conventions/DeleteBehaviorAttributeConvention.cs b/src/EFCore/Metadata/Conventions/DeleteBehaviorAttributeConvention.cs
@@ -11,7 +11,7 @@ namespace Microsoft.EntityFrameworkCore.Metadata.Conventions;
 /// <remarks>
 ///     See <see href="https://aka.ms/efcore-docs-conventions">Model building conventions</see> for more information and examples.
 /// </remarks>
-public class DeleteBehaviorAttributeConvention : PropertyAttributeConventionBase<DeleteBehaviorAttribute>, INavigationAddedConvention
+public class DeleteBehaviorAttributeConvention : PropertyAttributeConventionBase<DeleteBehaviorAttribute>, INavigationAddedConvention, IForeignKeyPrincipalEndChangedConvention, IModelFinalizingConvention
 {
     /// <summary>
     ///     Creates a new instance of <see cref="DeleteBehaviorAttributeConvention" />.
@@ -55,9 +55,74 @@ public void ProcessNavigationAdded(IConventionNavigationBuilder navigationBuilde
         }
 
         var foreignKey = navigationBuilder.Metadata.ForeignKey;
+        if (foreignKey.IsUnique)
+        {
+            return;
+        }
+
         if (foreignKey.GetDeleteBehaviorConfigurationSource() != ConfigurationSource.Explicit)
         {
             foreignKey.SetDeleteBehavior(navAttribute.Behavior);
         }
     }
+
+    /// <summary>
+    ///     Called after the principal end of a foreign key is changed.
+    /// </summary>
+    /// <param name="relationshipBuilder">The builder for the foreign key.</param>
+    /// <param name="context">Additional information associated with convention execution.</param>
+    public void ProcessForeignKeyPrincipalEndChanged(IConventionForeignKeyBuilder relationshipBuilder, IConventionContext<IConventionForeignKeyBuilder> context)
+    {
+        if (!relationshipBuilder.Metadata.IsUnique)
+        {
+            return;
+        }
+
+        var navigation = relationshipBuilder.Metadata.DependentToPrincipal;
+        if (navigation == null)
+        {
+            return;
+        }
+
+        var navAttribute = navigation.PropertyInfo?.GetCustomAttribute<DeleteBehaviorAttribute>();
+        if (navAttribute == null)
+        {
+            return;
+        }
+
+        if (relationshipBuilder.Metadata.GetDeleteBehaviorConfigurationSource() != ConfigurationSource.Explicit)
+        {
+            relationshipBuilder.Metadata.SetDeleteBehavior(navAttribute.Behavior);
+        }
+    }
+
+    /// <summary>
+    ///     Called when a model is being finalized.
+    /// </summary>
+    /// <param name="modelBuilder">The builder for the model.</param>
+    /// <param name="context">Additional information associated with convention execution.</param>
+    public void ProcessModelFinalizing(IConventionModelBuilder modelBuilder, IConventionContext<IConventionModelBuilder> context)
+    {
+        foreach (var entityType in modelBuilder.Metadata.GetEntityTypes())
+        {
+            foreach (var navigation in entityType.GetNavigations())
+            {
+                if (!navigation.ForeignKey.IsUnique)
+                {
+                    return;
+                }
+
+                var navAttribute = navigation.PropertyInfo?.GetCustomAttribute<DeleteBehaviorAttribute>();
+                if (navAttribute == null)
+                {
+                    return;
+                }
+
+                if (!navigation.IsOnDependent)
+                {
+                    throw new InvalidOperationException(CoreStrings.DeleteBehaviorAttributeOnPrincipalProperty);
+                }
+            }
+        }
+    }
 }
diff --git a/src/EFCore/Metadata/Conventions/Infrastructure/ProviderConventionSetBuilder.cs b/src/EFCore/Metadata/Conventions/Infrastructure/ProviderConventionSetBuilder.cs
@@ -214,6 +214,7 @@ public virtual ConventionSet CreateConventionSet()
         conventionSet.ForeignKeyPrincipalEndChangedConventions.Add(foreignKeyPropertyDiscoveryConvention);
         conventionSet.ForeignKeyPrincipalEndChangedConventions.Add(requiredNavigationAttributeConvention);
         conventionSet.ForeignKeyPrincipalEndChangedConventions.Add(nonNullableNavigationConvention);
+        conventionSet.ForeignKeyPrincipalEndChangedConventions.Add(deleteBehaviorAttributeConvention);
 
         conventionSet.PropertyNullabilityChangedConventions.Add(foreignKeyPropertyDiscoveryConvention);
 
@@ -242,6 +243,7 @@ public virtual ConventionSet CreateConventionSet()
         conventionSet.ModelFinalizingConventions.Add(new QueryFilterRewritingConvention(Dependencies));
         conventionSet.ModelFinalizingConventions.Add(inversePropertyAttributeConvention);
         conventionSet.ModelFinalizingConventions.Add(backingFieldConvention);
+        conventionSet.ModelFinalizingConventions.Add(deleteBehaviorAttributeConvention);
 
         conventionSet.ModelFinalizedConventions.Add(new RuntimeModelConvention(Dependencies));