Adding AggregateAttribute to prefetch specific relationship

Applying AggregateAttribute on Tags for example

--HG--
branch : 1.x

src/Orchard.Web/Modules/Orchard.Tags/Models/ContentTagRecord.cs

@@ -1,7 +1,12 @@
+using Orchard.Data.Conventions;
+
 namespace Orchard.Tags.Models {
     public class ContentTagRecord {
         public virtual int Id { get; set; }
+
+        [Aggregate]
         public virtual TagRecord TagRecord { get; set; }
+        
         public virtual TagsPartRecord TagsPartRecord { get; set; }
     }
 }

src/Orchard.Web/Modules/Orchard.Tags/Models/TagsPartRecord.cs

@@ -1,11 +1,14 @@
 using System.Collections.Generic;
 using Orchard.ContentManagement.Records;
+using Orchard.Data.Conventions;
 
 namespace Orchard.Tags.Models {
     public class TagsPartRecord : ContentPartRecord {
         public TagsPartRecord() {
             Tags = new List<ContentTagRecord>();
         }
+
+        [Aggregate]
         public virtual IList<ContentTagRecord> Tags { get; set; }
     }
 }

src/Orchard/Data/Conventions/AggregateAttribute.cs

@@ -0,0 +1,40 @@
+using System;
+using FluentNHibernate.Conventions;
+using FluentNHibernate.Conventions.AcceptanceCriteria;
+using FluentNHibernate.Conventions.Inspections;
+using FluentNHibernate.Conventions.Instances;
+
+namespace Orchard.Data.Conventions
+{
+    /// <summary>
+    /// This attribute is used to mark relationships which need to be eagerly fetched with the parent object,
+    /// thus defining an aggregate in terms of DDD
+    /// </summary>
+    public class AggregateAttribute : Attribute
+    {
+    }
+
+    public class ReferenceConvention : IReferenceConvention, IReferenceConventionAcceptance, IHasManyConvention, IHasManyConventionAcceptance
+    {
+        public void Apply(IManyToOneInstance instance)
+        {
+            instance.Fetch.Join();
+        }
+
+        public void Accept(IAcceptanceCriteria<IManyToOneInspector> criteria)
+        {
+            criteria.Expect(x => x.Property != null && x.Property.IsDefined(typeof(AggregateAttribute), false));
+        }
+    
+        public void  Apply(IOneToManyCollectionInstance instance)
+        {
+            instance.Fetch.Join();
+        }
+
+        public void Accept(IAcceptanceCriteria<IOneToManyCollectionInspector> criteria)
+        {
+            criteria.Expect(x => x.Member != null && x.Member.IsDefined(typeof(AggregateAttribute), false));
+        }
+    }
+}
+

src/Orchard/Orchard.Framework.csproj

@@ -177,6 +177,7 @@
     <Compile Include="ContentManagement\ImportContentSession.cs" />
     <Compile Include="ContentManagement\QueryHints.cs" />
     <Compile Include="ContentManagement\Utilities\ComputedField.cs" />
+    <Compile Include="Data\Conventions\AggregateAttribute.cs" />
     <Compile Include="DisplayManagement\Descriptors\PlacementInfo.cs" />
     <Compile Include="DisplayManagement\Descriptors\ResourceBindingStrategy\StylesheetBindingStrategy.cs" />
     <Compile Include="DisplayManagement\Descriptors\ShapeDescriptor.cs" />