Move Validate() method to MemberAccessor

In preparation for centralizing around `ItemConfiguration`, we need to move the `Validate()` method from `PropertyConfiguration` to `MemberAccessor`.

This is because it relies on access to the `MemberAccessor`'s `GetValue()` method. Currently, `PropertyConfiguration` has access to that via its `MemberAccessor` property. But once `ItemConfiguration` becomes a property off of `ItemMetadata`, it doesn't make sense to maintain the `ItemMetadata` or `MemberAccessor` fields off of `ItemConfiguration` or `PropertyConfiguration`.

Instead, callers will simply pass references to `ItemMetadata` (which will include `ItemConfiguration`) instead of `ItemConfiguration` (which previously included `ItemMetadata`). Basically, we're flipping the relationship between these.

Further, this can't be added to the `ItemMetadata` base class since it requires access to the `GetValue()` method on the derived `MemberAccessor` class. That's the same reason it was previously added to the `PropertyConfiguration`, not the `ItemConfiguration` class.

Author: JeremyCaney

OnTopic/Internal/Reflection/MemberAccessor.cs

@@ -3,6 +3,7 @@
 | Client        Ignia, LLC
 | Project       Topics Library
 \=============================================================================================================================*/
+using System.ComponentModel.DataAnnotations;
 using System.Reflection;
 using OnTopic.Attributes;
 
@@ -218,6 +219,20 @@ internal void SetValue(object target, object? value, bool allowConversion = fals
 
     }
 
+    /*==========================================================================================================================
+    | METHOD: VALIDATE
+    \-------------------------------------------------------------------------------------------------------------------------*/
+    /// <summary>
+    ///   Given a target DTO, will automatically identify any attributes that derive from <see cref="ValidationAttribute"/> and
+    ///   ensure that their conditions are satisfied.
+    /// </summary>
+    /// <param name="target">The target DTO to validate the current property on.</param>
+    internal void Validate(object target) {
+      foreach (ValidationAttribute validator in CustomAttributes.OfType<ValidationAttribute>()) {
+        validator.Validate(GetValue(target), Name);
+      }
+    }
+
     /*==========================================================================================================================
     | IS VALID?
     \-------------------------------------------------------------------------------------------------------------------------*/

OnTopic/Mapping/Internal/PropertyConfiguration.cs

@@ -3,7 +3,6 @@
 | Client        Ignia, LLC
 | Project       Topics Library
 \=============================================================================================================================*/
-using System.ComponentModel.DataAnnotations;
 using System.Reflection;
 using OnTopic.Internal.Reflection;
 using OnTopic.Mapping.Annotations;
@@ -57,19 +56,5 @@ internal PropertyConfiguration(MemberAccessor memberAccessor, string? attributeP
     /// </summary>
     internal MemberAccessor MemberAccessor { get; }
 
-    /*==========================================================================================================================
-    | METHOD: VALIDATE
-    \-------------------------------------------------------------------------------------------------------------------------*/
-    /// <summary>
-    ///   Given a target DTO, will automatically identify any attributes that derive from <see cref="ValidationAttribute"/> and
-    ///   ensure that their conditions are satisfied.
-    /// </summary>
-    /// <param name="target">The target DTO to validate the current property on.</param>
-    internal void Validate(object target) {
-      foreach (ValidationAttribute validator in CustomAttributes.OfType<ValidationAttribute>()) {
-        validator.Validate(MemberAccessor.GetValue(target), MemberAccessor.Name);
-      }
-    }
-
   }
 }

OnTopic/Mapping/Reverse/ReverseTopicMappingService.cs

@@ -286,7 +286,7 @@ await MapAsync(
       /*------------------------------------------------------------------------------------------------------------------------
       | Validate fields
       \-----------------------------------------------------------------------------------------------------------------------*/
-      configuration.Validate(source);
+      propertyAccessor.Validate(source);
 
       /*------------------------------------------------------------------------------------------------------------------------
       | Handle property by type

OnTopic/Mapping/TopicMappingService.cs

@@ -513,7 +513,7 @@ await MapAsync(
       /*------------------------------------------------------------------------------------------------------------------------
       | Validate fields
       \-----------------------------------------------------------------------------------------------------------------------*/
-      configuration.Validate(target);
+      propertyAccessor.Validate(target);
 
     }