Renamed [Relationship()] attribute to [Collection()]

Originally, the `[Relationship()]` attribute was intended to disambiguate references to `Topic.Relationships` and `Topic.IncomingRelationships`. Almost as soon as it was conceived of, however, it was expanded to include e.g. `Topic.Children`, as well as mapped collections (i.e., strongly typed collections with compatible types), and nested topics (a specialized type of `Topic.Children`).

Technically, we can argue that all of these are types of relationships. But the name remains ambiguous and unintuitive, since it sounds specific to `Topic.Relationships`. To mitigate that, it's being renamed to `[Collection()]`, which better articulates that it's clarifying the mapping between the source collection and the target collection, independent of whether or not it's a relationship attribute.

OnTopic.Tests/BindingModels/InvalidRelationshipTypeTopicBindingModel.cs

@@ -25,7 +25,7 @@ public class InvalidRelationshipTypeTopicBindingModel : BasicTopicBindingModel {
 
     public InvalidRelationshipTypeTopicBindingModel(string? key = null) : base(key, "ContentTypeDescriptor") { }
 
-    [Relationship(RelationshipType.NestedTopics)]
+    [Collection(RelationshipType.NestedTopics)]
     public Collection<RelatedTopicBindingModel> ContentTypes { get; } = new();
 
   } //Class

OnTopic.Tests/TopicMappingServiceTest.cs

@@ -384,11 +384,11 @@ public async Task Map_Relationships_SkipsDisabled() {
     \-------------------------------------------------------------------------------------------------------------------------*/
     /// <summary>
     ///   Establishes a <see cref="TopicMappingService"/> and tests whether it successfully derives values from the key and
-    ///   type specified by <see cref="Mapping.Annotations.RelationshipAttribute"/>.
+    ///   type specified by <see cref="Mapping.Annotations.CollectionAttribute"/>.
     /// </summary>
     /// <remarks>
     ///   The <see cref="AmbiguousRelationTopicViewModel.RelationshipAlias"/> uses <see
-    ///   cref="Mapping.Annotations.RelationshipAttribute"/> to set the relationship key to <c>AmbiguousRelationship</c> and the
+    ///   cref="Mapping.Annotations.CollectionAttribute"/> to set the relationship key to <c>AmbiguousRelationship</c> and the
     ///   <see cref="RelationshipType"/> to <see cref="RelationshipType.IncomingRelationship"/>. <c>AmbiguousRelationship</c>
     ///   refers to a relationship that is both outgoing and incoming. It should be smart enough to a) look for the
     ///   <c>AmbigousRelationship</c> instead of the <c>RelationshipAlias</c>, and b) source from the <see

OnTopic.Tests/ViewModels/AmbiguousRelationTopicViewModel.cs

@@ -16,7 +16,7 @@ namespace OnTopic.Tests.ViewModels {
   /// </summary>
   /// <remarks>
   ///   <para>
-  ///     The <see cref="RelationshipAlias"/> uses <see cref="RelationshipAttribute"/> to set the relationship key to
+  ///     The <see cref="RelationshipAlias"/> uses <see cref="CollectionAttribute"/> to set the relationship key to
   ///     <c>AmbiguousRelationship</c> and the <see cref="RelationshipType"/> to <see
   ///     cref="RelationshipType.IncomingRelationship"/>. <c>AmbiguousRelationship</c> refers to a relationship that is both
   ///     outgoing and incoming.
@@ -27,7 +27,7 @@ namespace OnTopic.Tests.ViewModels {
   /// </remarks>
   public class AmbiguousRelationTopicViewModel: KeyOnlyTopicViewModel {
 
-    [Relationship("AmbiguousRelationship", Type=RelationshipType.IncomingRelationship)]
+    [Collection("AmbiguousRelationship", Type=RelationshipType.IncomingRelationship)]
     public Collection<KeyOnlyTopicViewModel> RelationshipAlias { get; } = new();
 
   } //Class

OnTopic.Tests/ViewModels/Metadata/ContentTypeDescriptorTopicViewModel.cs

@@ -22,7 +22,7 @@ public class ContentTypeDescriptorTopicViewModel {
 
     public Collection<AttributeDescriptorTopicViewModel> AttributeDescriptors { get; } = new();
 
-    [Relationship(RelationshipType.MappedCollection)]
+    [Collection(RelationshipType.MappedCollection)]
     [Follow(Relationships.None)]
     public Collection<ContentTypeDescriptorTopicViewModel> PermittedContentTypes { get; } = new();
 

OnTopic/Mapping/Annotations/RelationshipAttribute.cs → OnTopic/Mapping/Annotations/CollectionAttribute.cs

@@ -7,7 +7,7 @@
 namespace OnTopic.Mapping.Annotations {
 
   /*============================================================================================================================
-  | ATTRIBUTE: RELATIONSHIP
+  | ATTRIBUTE: COLLECTION
   \---------------------------------------------------------------------------------------------------------------------------*/
   /// <summary>
   ///   Provides the <see cref="ITopicMappingService"/> with instructions as to which key to follow for the relationship.
@@ -21,32 +21,32 @@ namespace OnTopic.Mapping.Annotations {
   ///   </para>
   ///   <para>
   ///     This attribute instructs the <see cref="ITopicMappingService"/> to instead look for a specified key. This allows the
-  ///     target property name to be decoupled from the source's relationship key. In addition, this attribute can be used to
-  ///     specify the type of relationship expected, which is useful if there might be ambiguity between relationship names (for
-  ///     example, if there is a <see cref="Topic.Relationships"/> with the same key as an <see
-  ///     cref="Topic.IncomingRelationships"/>).
+  ///     target property name to be decoupled from the source's collection key. In addition, this attribute can be used to
+  ///     specify the type of collection expected, which is useful if there might be ambiguity between collection names (for
+  ///     example, if there is a <see cref="Topic.Relationships"/> with the same key as an <see cref="Topic.
+  ///     IncomingRelationships"/>), which is not an uncommon scenario.
   ///   </para>
   /// </remarks>
   [System.AttributeUsage(System.AttributeTargets.Property)]
-  public sealed class RelationshipAttribute : System.Attribute {
+  public sealed class CollectionAttribute : System.Attribute {
 
     /*==========================================================================================================================
     | CONSTRUCTOR
     \-------------------------------------------------------------------------------------------------------------------------*/
     /// <summary>
-    ///   Annotates a property with the <see cref="RelationshipAttribute"/> by providing an <paramref name="key"/>.
+    ///   Annotates a property with the <see cref="CollectionAttribute"/> by providing an <paramref name="key"/>.
     /// </summary>
     /// <param name="key">The key value of the relationships associated with the current property.</param>
-    public RelationshipAttribute(string key) {
+    public CollectionAttribute(string key) {
       TopicFactory.ValidateKey(key, false);
       Key = key;
     }
 
     /// <summary>
-    ///   Annotates a property with the <see cref="RelationshipAttribute"/> by providing the <see cref="RelationshipType"/>.
+    ///   Annotates a property with the <see cref="CollectionAttribute"/> by providing the <see cref="RelationshipType"/>.
     /// </summary>
     /// <param name="type">Optional. The type of collection the relationship is associated with.</param>
-    public RelationshipAttribute(RelationshipType type = RelationshipType.Any) {
+    public CollectionAttribute(RelationshipType type = RelationshipType.Any) {
       Type = type;
     }
 

OnTopic/Mapping/Internal/PropertyConfiguration.cs

@@ -92,7 +92,7 @@ public PropertyConfiguration(PropertyInfo property, string? attributePrefix = ""
       /*------------------------------------------------------------------------------------------------------------------------
       | Attributes: Determine relationship key and type
       \-----------------------------------------------------------------------------------------------------------------------*/
-      GetAttributeValue<RelationshipAttribute>(
+      GetAttributeValue<CollectionAttribute>(
         property,
         a => {
           RelationshipKey = a.Key ?? RelationshipKey;
@@ -248,7 +248,7 @@ public PropertyConfiguration(PropertyInfo property, string? attributePrefix = ""
     ///     the DTO to be aliased to a different collection name on the source <see cref="Topic"/>.
     ///   </para>
     ///   <para>
-    ///     The <see cref="RelationshipKey"/> property corresponds to the <see cref="RelationshipAttribute.Key"/> property. It
+    ///     The <see cref="RelationshipKey"/> property corresponds to the <see cref="CollectionAttribute.Key"/> property. It
     ///     can be assigned by decorating a DTO property with e.g. <c>[Relationship("AlternateRelationshipKey")]</c>.
     ///   </para>
     /// </remarks>
@@ -269,7 +269,7 @@ public PropertyConfiguration(PropertyInfo property, string? attributePrefix = ""
     ///     be ambiguous between multiple collections.
     ///   </para>
     ///   <para>
-    ///     The <see cref="RelationshipType"/> property corresponds to the <see cref="RelationshipAttribute.Type"/> property. It
+    ///     The <see cref="RelationshipType"/> property corresponds to the <see cref="CollectionAttribute.Type"/> property. It
     ///     can be assigned by decorating a DTO property with e.g. <c>[Relationship("AlternateRelationshipKey",
     ///     RelationshipType.Children)]</c>.
     ///   </para>

OnTopic/Mapping/Reverse/IReverseTopicMappingService.cs

@@ -36,7 +36,7 @@ namespace OnTopic.Mapping.Reverse {
   ///     Despite the differences between the <see cref="ITopicMappingService"/> and <see cref="IReverseTopicMappingService"/>s,
   ///     many attributes are able to be reused between them. For instance, the <see cref="AttributeKeyAttribute"/> can still
   ///     map a property on a binding model to an attribute of a different name on a <see cref="Topic"/>, just as the <see
-  ///     cref="RelationshipAttribute"/> can with relationships. Other attributes, however, provde no benefit in the reverse
+  ///     cref="CollectionAttribute"/> can with relationships. Other attributes, however, provde no benefit in the reverse
   ///     scenario, such as <see cref="FlattenAttribute"/> or <see cref="FilterByAttributeAttribute"/>, which really only make
   ///     sense in creating a "produced view" that is a subset of the original model. That is valuable when creating a view
   ///     model, but isn't a useful use case when working with binding models.