Add IsExtendedAttributeMismatch() logic into GetAttributes()

Added a private helper method, `IsExtendedAttributeMismatch()`, to `TopicRepositoryBase`, which will detect a mismatch between where an existing `AttributeValue` _has been_ saved, and where it _should be_ saved according to the `AttributeDescriptor. This allows us to identify scenarios where the conigured storage location has changed since the attribute value was last saved.

This `IsExtendedAttributeMismatch()` method is encorporated into the `GetAttributes()` method such that any mismatched attributes will be returned if `isDirty` is `true`—even if `AttributeValue.IsDirty` is `false`. This is important because even though the _value_ hasn't changed, the _storage location_ has and, therefore, it should be treated _as though_ it were `IsDirty`.

This includes two unit test cases to validate this functionality—one to make sure that `!IsDirty` attributes are returned if `IsExtendedAttributeMismatch()` is true, and another to make sure they _aren't_ returned if the `isExtendedAttribute` parameter doesn't match the `AttributeDescriptor.IsExtendedAttribute` property.

Author: JeremyCaney

OnTopic.Tests/TopicRepositoryBaseTest.cs

@@ -129,6 +129,51 @@ public void GetAttributes_ExtendedAttributes_ReturnsExtendedAttributes() {
 
     }
 
+    /*==========================================================================================================================
+    | TEST: GET ATTRIBUTES: EXTENDED ATTRIBUTE MISMATCH: RETURNS EXTENDED ATTRIBUTES
+    \-------------------------------------------------------------------------------------------------------------------------*/
+    /// <summary>
+    ///   Retrieves a list of attributes from a topic, filtering by <see cref="AttributeValue.IsDirty"/>. Expects an <see
+    ///   cref="AttributeValue"/> to be returned even if it's <i>not</i> <see cref="AttributeValue.IsDirty"/> <i>but</i> its
+    ///   <see cref="AttributeValue.IsExtendedAttribute"/> disagrees with <see cref="AttributeDescriptor.IsExtendedAttribute"/>.
+    /// </summary>
+    [TestMethod]
+    public void GetAttributes_ExtendedAttributeMismatch_ReturnsExtendedAttributes() {
+
+      var topic                 = TopicFactory.Create("Test", "ContentTypes");
+
+      topic.Attributes.SetValue("Title", "Title", isDirty:false, isExtendedAttribute:false);
+
+      var attributes            = _topicRepository.GetAttributesProxy(topic, true, true);
+
+      //Expect Title, even though it isn't IsDirty
+      Assert.AreEqual<int>(1, attributes.Count());
+
+    }
+
+    /*==========================================================================================================================
+    | TEST: GET ATTRIBUTES: EXTENDED ATTRIBUTE MISMATCH: RETURNS NOTHING
+    \-------------------------------------------------------------------------------------------------------------------------*/
+    /// <summary>
+    ///   Retrieves a list of attributes from a topic, filtering by <see cref="AttributeValue.IsDirty"/>. Expects the <see
+    ///   cref="AttributeValue"/> to <i>not</i> be returned even though its <see cref="AttributeValue.IsExtendedAttribute"/>
+    ///   disagrees with <see cref="AttributeDescriptor.IsExtendedAttribute"/>, since it won't match the <see
+    ///   cref="TopicRepositoryBase.GetAttributes(Topic, Boolean?, Boolean?, Boolean)"/>'s <c>isExtendedAttribute</c> call.
+    /// </summary>
+    [TestMethod]
+    public void GetAttributes_ExtendedAttributeMismatch_ReturnsNothing() {
+
+      var topic                 = TopicFactory.Create("Test", "ContentTypes");
+
+      topic.Attributes.SetValue("Title", "Title", isDirty: false, isExtendedAttribute: false);
+
+      var attributes            = _topicRepository.GetAttributesProxy(topic, false, true);
+
+      //Expect Key and ContentType, but not Title
+      Assert.AreEqual<int>(2, attributes.Count());
+
+    }
+
     /*==========================================================================================================================
     | TEST: GET ATTRIBUTES: ARBITRARY ATTRIBUTE WITH SHORT VALUE: RETURNS AS INDEXED ATTRIBUTE
     \-------------------------------------------------------------------------------------------------------------------------*/

OnTopic/Repositories/TopicRepositoryBase.cs

@@ -515,7 +515,7 @@ protected IEnumerable<AttributeValue> GetAttributes(Topic topic, bool? isExtende
       \-----------------------------------------------------------------------------------------------------------------------*/
       var attributes            = new List<AttributeValue>();
 
-      foreach (var attributeValue in topic.Attributes.Where(a => isDirty == null || a.IsDirty == isDirty)) {
+      foreach (var attributeValue in topic.Attributes) {
 
         var key                 = attributeValue.Key;
         var attribute           = (AttributeDescriptor?)null;
@@ -536,6 +536,19 @@ protected IEnumerable<AttributeValue> GetAttributes(Topic topic, bool? isExtende
           continue;
         }
 
+        //Skip if attribute's isDirty flag doesn't match the callers preference. Alternatively, if the IsExtendedAttribute value
+        //doesn't match the source, as this implies the storage location has changed, and the attribute should be treated as
+        //isDirty.
+        if (
+          isDirty == null ||
+          attributeValue.IsDirty == isDirty ||
+          isDirty == IsExtendedAttributeMismatch(attribute, attributeValue)
+        ) {
+        }
+        else {
+          continue;
+        }
+
         //Add the attribute based on the isExtendedAttribute paramter. Add all parameters if isExtendedAttribute is null. Assume
         //an attribute is extended if the corresponding attribute descriptor cannot be located and the value is over 255
         //characters.
@@ -643,6 +656,38 @@ topic is AttributeDescriptor &&
       topic.Parent?.Key == "Attributes" &&
       topic.Parent.Parent is ContentTypeDescriptor;
 
+
+    /*==========================================================================================================================
+    | METHOD: IS EXTENDED ATTRIBUTE MISMATCH?
+    \-------------------------------------------------------------------------------------------------------------------------*/
+    /// <summary>
+    ///   Determines whether or not there's a mismatch between the <see cref="AttributeDescriptor.IsExtendedAttribute"/> and the
+    ///   <see cref="AttributeValue.IsExtendedAttribute"/>.
+    /// </summary>
+    /// <remarks>
+    ///   <para>
+    ///     The <see cref="AttributeDescriptor.IsExtendedAttribute"/> determines where an attribute <i>should</i> be stored; the
+    ///     <see cref="AttributeValue.IsExtendedAttribute"/> determines where an attribute <i>was</i> stored. If these two
+    ///     values are in conflict, that suggests the coniguration for <see cref="AttributeDescriptor.IsExtendedAttribute"/> has
+    ///     changed since the attribute value was last saved. In that case, it should be treated as <see
+    ///     cref="AttributeValue.IsDirty"/> <i>even though</i> its value hasn't changed to ensure that its storage location is
+    ///     updated.
+    ///   </para>
+    ///   <para>
+    ///     If <see cref="AttributeDescriptor"/> cannot be found then the <see cref="AttributeValue"/> is arbitrary attribute
+    ///     not mapped to the schema. In that case, its storage location is dynamically determined based on its length, and thus
+    ///     it should only change locations when it <see cref="AttributeValue.IsDirty"/>. Otherwise, its length will remain the
+    ///     same, and thus the storage location should remain unchanged.
+    ///   </para>
+    /// </remarks>
+    /// <param name="attributeDescriptor">The source <see cref="AttributeDescriptor"/>, if available.</param>
+    /// <param name="attributeValue">The target <see cref="AttributeValue"/>.</param>
+    /// <returns></returns>
+    private static bool IsExtendedAttributeMismatch(AttributeDescriptor? attributeDescriptor, AttributeValue attributeValue) =>
+      attributeDescriptor != null &&
+      attributeValue.IsExtendedAttribute != null &&
+      attributeDescriptor.IsExtendedAttribute != attributeValue.IsExtendedAttribute;
+
     /*==========================================================================================================================
     | METHOD: RESET ATTRIBUTE DESCRIPTORS
     \-------------------------------------------------------------------------------------------------------------------------*/