Added AttributeDictionary constructors to each of the view models

The models in `OnTopic.ViewModels` are intended to be the standard reference models used for out-of-the-box implementations of OnTopic, and should be optimized for readability and performance, while also demonstrating best practices. To this end, I've added support for the new `AttributeDictionary` constructor to each of these, thus allowing them to bypass reflection for standard scalar properties.

Equally importantly, while not all implementors will choose to create `AttributeDictionary` constructors for their own view models, we want to support those who do, and do so by basing their implementation on the `OnTopic.ViewModels` library. By ensuring there's an `AttributeDictionary` constructor on every model—even models that aren't used very often and might not otherwise benefit from this functionality—we make it possible for any model in `OnTopic.ViewModels` to be subclassed and to have an `AttributeDictionary` constructor defined on that derived type without needing to implement properties of all base types.

This should improve both performance of the `OnTopic.ViewModels` when used directly. while offering flexibility for implementors to fully adopt `AttributeDictionary` constructors on their own derived view models, should they choose to do so.

This completes the basic implementation of the `AttributeDictionary` support for the `TopicMappingService` as required by Feature #99. That said, we still need to extend our unit tests to cover `AttributeDictionary` and the new `MapAsync()` functionality.

Author: JeremyCaney

OnTopic.ViewModels/Properties/AssemblyInfo.cs

@@ -9,6 +9,8 @@
 \-----------------------------------------------------------------------------------------------------------------------------*/
 global using System.ComponentModel.DataAnnotations;
 global using System.Diagnostics.CodeAnalysis;
+global using OnTopic.Attributes;
+global using OnTopic.Internal.Diagnostics;
 global using OnTopic.Models;
 
 /*==============================================================================================================================

OnTopic.ViewModels/TopicViewModel.cs

@@ -20,6 +20,24 @@ namespace OnTopic.ViewModels {
   /// </remarks>
   public record TopicViewModel: ITopicViewModel, ICoreTopicViewModel, IAssociatedTopicBindingModel, ITopicBindingModel {
 
+    /*==========================================================================================================================
+    | CONSTRUCTOR
+    \-------------------------------------------------------------------------------------------------------------------------*/
+    /// <summary>
+    ///   Initializes a new <see cref="TopicViewModel"/> with an <paramref name="attributes"/> dictionary.
+    /// </summary>
+    /// <param name="attributes">An <see cref="AttributeDictionary"/> of attribute values.</param>
+    public TopicViewModel(AttributeDictionary attributes) {
+      Contract.Requires(attributes, nameof(attributes));
+      IsHidden                  = attributes.GetBoolean("IsHidden")?? false;
+      View                      = attributes.GetValue("View");
+    }
+
+    /// <summary>
+    ///   Initializes a new <see cref="TopicViewModel"/> with no parameters.
+    /// </summary>
+    public TopicViewModel() { }
+
     /*==========================================================================================================================
     | ID
     \-------------------------------------------------------------------------------------------------------------------------*/

OnTopic.ViewModels/_contentTypes/ContentListTopicViewModel.cs

@@ -19,6 +19,24 @@ namespace OnTopic.ViewModels {
   /// </remarks>
   public record ContentListTopicViewModel: PageTopicViewModel {
 
+    /*==========================================================================================================================
+    | CONSTRUCTOR
+    \-------------------------------------------------------------------------------------------------------------------------*/
+    /// <summary>
+    ///   Initializes a new <see cref="ContentListTopicViewModel"/> with an <paramref name="attributes"/> dictionary.
+    /// </summary>
+    /// <param name="attributes">An <see cref="AttributeDictionary"/> of attribute values.</param>
+    public ContentListTopicViewModel(AttributeDictionary attributes): base(attributes) {
+      Contract.Requires(attributes, nameof(attributes));
+      IsIndexed                 = attributes.GetBoolean(nameof(IsIndexed))?? false;
+      IndexLabel                = attributes.GetValue(nameof(IndexLabel))?? "Contents";
+    }
+
+    /// <summary>
+    ///   Initializes a new <see cref="ContentListTopicViewModel"/> with no parameters.
+    /// </summary>
+    public ContentListTopicViewModel() { }
+
     /*==========================================================================================================================
     | CONTENT ITEMS
     \-------------------------------------------------------------------------------------------------------------------------*/

OnTopic.ViewModels/_contentTypes/IndexTopicViewModel.cs

@@ -19,6 +19,20 @@ namespace OnTopic.ViewModels {
   /// </remarks>
   public record IndexTopicViewModel: PageTopicViewModel {
 
+    /*==========================================================================================================================
+    | CONSTRUCTOR
+    \-------------------------------------------------------------------------------------------------------------------------*/
+    /// <summary>
+    ///   Initializes a new <see cref="IndexTopicViewModel"/> with an <paramref name="attributes"/> dictionary.
+    /// </summary>
+    /// <param name="attributes">An <see cref="AttributeDictionary"/> of attribute values.</param>
+    public IndexTopicViewModel(AttributeDictionary attributes): base(attributes) { }
+
+    /// <summary>
+    ///   Initializes a new <see cref="IndexTopicViewModel"/> with no parameters.
+    /// </summary>
+    public IndexTopicViewModel() { }
+
 
   } //Class
 } //Namespace

OnTopic.ViewModels/_contentTypes/PageGroupTopicViewModel.cs

@@ -19,6 +19,20 @@ namespace OnTopic.ViewModels {
   /// </remarks>
   public record PageGroupTopicViewModel : SectionTopicViewModel {
 
+    /*==========================================================================================================================
+    | CONSTRUCTOR
+    \-------------------------------------------------------------------------------------------------------------------------*/
+    /// <summary>
+    ///   Initializes a new <see cref="PageGroupTopicViewModel"/> with an <paramref name="attributes"/> dictionary.
+    /// </summary>
+    /// <param name="attributes">An <see cref="AttributeDictionary"/> of attribute values.</param>
+    public PageGroupTopicViewModel(AttributeDictionary attributes): base(attributes) { }
+
+    /// <summary>
+    ///   Initializes a new <see cref="PageGroupTopicViewModel"/> with no parameters.
+    /// </summary>
+    public PageGroupTopicViewModel() { }
+
 
   } //Class
 } //Namespace

OnTopic.ViewModels/_contentTypes/PageTopicViewModel.cs

@@ -19,6 +19,29 @@ namespace OnTopic.ViewModels {
   /// </remarks>
   public record PageTopicViewModel: TopicViewModel, INavigableTopicViewModel {
 
+    /*==========================================================================================================================
+    | CONSTRUCTOR
+    \-------------------------------------------------------------------------------------------------------------------------*/
+    /// <summary>
+    ///   Initializes a new <see cref="PageTopicViewModel"/> with an <paramref name="attributes"/> dictionary.
+    /// </summary>
+    /// <param name="attributes">An <see cref="AttributeDictionary"/> of attribute values.</param>
+    public PageTopicViewModel(AttributeDictionary attributes): base(attributes) {
+      Contract.Requires(attributes, nameof(attributes));
+      ShortTitle                = attributes.GetValue(nameof(ShortTitle));
+      Subtitle                  = attributes.GetValue(nameof(Subtitle));
+      MetaTitle                 = attributes.GetValue(nameof(MetaTitle));
+      MetaDescription           = attributes.GetValue(nameof(MetaDescription));
+      MetaKeywords              = attributes.GetValue(nameof(MetaKeywords));
+      NoIndex                   = attributes.GetBoolean(nameof(NoIndex))?? false;
+      Body                      = attributes.GetValue(nameof(Body));
+    }
+
+    /// <summary>
+    ///   Initializes a new <see cref="PageTopicViewModel"/> with no parameters.
+    /// </summary>
+    public PageTopicViewModel() { }
+
     /*==========================================================================================================================
     | SHORT TITLE
     \-------------------------------------------------------------------------------------------------------------------------*/

OnTopic.ViewModels/_contentTypes/SectionTopicViewModel.cs

@@ -19,6 +19,23 @@ namespace OnTopic.ViewModels {
   /// </remarks>
   public record SectionTopicViewModel : TopicViewModel {
 
+    /*==========================================================================================================================
+    | CONSTRUCTOR
+    \-------------------------------------------------------------------------------------------------------------------------*/
+    /// <summary>
+    ///   Initializes a new <see cref="SectionTopicViewModel"/> with an <paramref name="attributes"/> dictionary.
+    /// </summary>
+    /// <param name="attributes">An <see cref="AttributeDictionary"/> of attribute values.</param>
+    public SectionTopicViewModel(AttributeDictionary attributes): base(attributes) {
+      Contract.Requires(attributes, nameof(attributes));
+      HeaderImageUrl            = attributes.GetUri(nameof(HeaderImageUrl));
+    }
+
+    /// <summary>
+    ///   Initializes a new <see cref="SectionTopicViewModel"/> with no parameters.
+    /// </summary>
+    public SectionTopicViewModel() { }
+
     /*==========================================================================================================================
     | HEADER IMAGE
     \-------------------------------------------------------------------------------------------------------------------------*/

OnTopic.ViewModels/_contentTypes/SlideshowTopicViewModel.cs

@@ -19,6 +19,23 @@ namespace OnTopic.ViewModels {
   /// </remarks>
   public record SlideshowTopicViewModel: ContentListTopicViewModel {
 
+    /*==========================================================================================================================
+    | CONSTRUCTOR
+    \-------------------------------------------------------------------------------------------------------------------------*/
+    /// <summary>
+    ///   Initializes a new <see cref="SlideshowTopicViewModel"/> with an <paramref name="attributes"/> dictionary.
+    /// </summary>
+    /// <param name="attributes">An <see cref="AttributeDictionary"/> of attribute values.</param>
+    public SlideshowTopicViewModel(AttributeDictionary attributes): base(attributes) {
+      Contract.Requires(attributes, nameof(attributes));
+      TransitionEffect          = attributes.GetValue(nameof(TransitionEffect));
+    }
+
+    /// <summary>
+    ///   Initializes a new <see cref="SlideshowTopicViewModel"/> with no parameters.
+    /// </summary>
+    public SlideshowTopicViewModel() { }
+
     /*==========================================================================================================================
     | TRANSITION EFFECT
     \-------------------------------------------------------------------------------------------------------------------------*/

OnTopic.ViewModels/_contentTypes/VideoTopicViewModel.cs

@@ -19,6 +19,24 @@ namespace OnTopic.ViewModels {
   /// </remarks>
   public record VideoTopicViewModel: PageTopicViewModel {
 
+    /*==========================================================================================================================
+    | CONSTRUCTOR
+    \-------------------------------------------------------------------------------------------------------------------------*/
+    /// <summary>
+    ///   Initializes a new <see cref="VideoTopicViewModel"/> with an <paramref name="attributes"/> dictionary.
+    /// </summary>
+    /// <param name="attributes">An <see cref="AttributeDictionary"/> of attribute values.</param>
+    public VideoTopicViewModel(AttributeDictionary attributes): base(attributes) {
+      Contract.Requires(attributes, nameof(attributes));
+      VideoUrl                  = attributes.GetUri(nameof(VideoUrl))!;
+      PosterUrl                 = attributes.GetUri(nameof(PosterUrl));
+    }
+
+    /// <summary>
+    ///   Initializes a new <see cref="VideoTopicViewModel"/> with no parameters.
+    /// </summary>
+    public VideoTopicViewModel() { }
+
     /*==========================================================================================================================
     | VIDEO URL
     \-------------------------------------------------------------------------------------------------------------------------*/

OnTopic.ViewModels/_items/CacheProfileTopicViewModel.cs

@@ -20,6 +20,27 @@ namespace OnTopic.ViewModels {
   /// </remarks>
   public record CacheProfileTopicViewModel: ItemTopicViewModel {
 
+    /*==========================================================================================================================
+    | CONSTRUCTOR
+    \-------------------------------------------------------------------------------------------------------------------------*/
+    /// <summary>
+    ///   Initializes a new <see cref="CacheProfileTopicViewModel"/> with an <paramref name="attributes"/> dictionary.
+    /// </summary>
+    /// <param name="attributes">An <see cref="AttributeDictionary"/> of attribute values.</param>
+    public CacheProfileTopicViewModel(AttributeDictionary attributes): base(attributes) {
+      Contract.Requires(attributes, nameof(attributes));
+      Duration                  = attributes.GetInteger(nameof(Duration));
+      Location                  = attributes.GetValue(nameof(Location));
+      NoStore                   = attributes.GetBoolean(nameof(NoStore));
+      VaryByHeader              = attributes.GetValue(nameof(VaryByHeader));
+      VaryByQueryKeys           = attributes.GetValue(nameof(VaryByQueryKeys));
+    }
+
+    /// <summary>
+    ///   Initializes a new <see cref="CacheProfileTopicViewModel"/> with no parameters.
+    /// </summary>
+    public CacheProfileTopicViewModel() { }
+
     /*==========================================================================================================================
     | DURATION
     \-------------------------------------------------------------------------------------------------------------------------*/