feat: working on making handlebars a little less painful

src/Nitride.Handlebars/ApplyStyleTemplate.cs

@@ -15,18 +15,18 @@ namespace Nitride.Handlebars;
 /// An operation that applies a common or shared template on the content of
 /// a document that includes theme or styling information.
 /// </summary>
-public class ApplyStyleTemplate<TModel> : OperationBase
+[WithProperties]
+public partial class ApplyStyleTemplate : OperationBase
 {
-    // TODO: This does not use [WithProperties] because the source generator hasn't been taught how to do generics.
-
     private readonly HandlebarsTemplateCache cache;
 
-    private readonly IValidator<ApplyStyleTemplate<TModel>> validator;
+    private readonly IValidator<ApplyStyleTemplate> validator;
 
-    public ApplyStyleTemplate(HandlebarsTemplateCache cache)
+    public ApplyStyleTemplate(
+        IValidator<ApplyStyleTemplate> validator,
+        HandlebarsTemplateCache cache)
     {
-        // TODO: Figure out why Autofac won't let us register IValidator of generic classes.
-        this.validator = new ApplyStyleTemplateValidator<TModel>();
+        this.validator = validator;
         this.cache = cache;
     }
 
@@ -35,7 +35,7 @@ public class ApplyStyleTemplate<TModel> : OperationBase
     /// entity. This allows for the website to customize what information is
     /// being passed to the template.
     /// </summary>
-    public Func<Entity, TModel>? CreateModelCallback { get; set; }
+    public Func<Entity, object>? CreateModelCallback { get; set; }
 
     /// <summary>
     /// Gets or sets the callback used to determine which template to use
@@ -55,38 +55,11 @@ public class ApplyStyleTemplate<TModel> : OperationBase
         return input.SelectEntity<ITextContent>(this.Apply);
     }
 
-    /// <summary>
-    /// Sets the callback for the template and returns the operation to
-    /// chain operations.
-    /// </summary>
-    /// <param name="callback">The callback to set.</param>
-    /// <returns>The ApplyContentHandlebarsTemplate to chain requests.</returns>
-    public ApplyStyleTemplate<TModel> WithCreateModelCallback(Func<Entity, TModel>? callback)
-    {
-        this.CreateModelCallback = callback;
-
-        return this;
-    }
-
-    public ApplyStyleTemplate<TModel> WithGetTemplateName(Func<Entity, string>? callback)
-    {
-        this.GetTemplateName = callback;
-
-        return this;
-    }
-
-    public ApplyStyleTemplate<TModel> WithHandlebars(IHandlebars? handlebars)
-    {
-        this.Handlebars = handlebars;
-
-        return this;
-    }
-
     private Entity Apply(
         Entity entity,
         ITextContent content)
     {
-        TModel model = this.CreateModelCallback!(entity);
+        object model = this.CreateModelCallback!(entity);
         string name = this.GetTemplateName!(entity);
         HandlebarsTemplate<object, object> template = this.cache.GetNamedTemplate(name);
         string result = template(model!);

src/Nitride.Handlebars/ApplyStyleTemplateValidator.cs

@@ -2,7 +2,7 @@ using FluentValidation;
 
 namespace Nitride.Handlebars;
 
-public class ApplyStyleTemplateValidator<TModel> : AbstractValidator<ApplyStyleTemplate<TModel>>
+public class ApplyStyleTemplateValidator : AbstractValidator<ApplyStyleTemplate>
 {
     public ApplyStyleTemplateValidator()
     {

src/Nitride.Handlebars/Configuration/FileSystemHandlebarsTemplateLoader.cs

@@ -0,0 +1,35 @@
+using System.IO;
+
+using HandlebarsDotNet;
+
+namespace Nitride.Handlebars.Configuration;
+
+/// <summary>
+/// Loads the templates from the given directory.
+/// </summary>
+public class FileSystemHandlebarsTemplateLoader : IHandlebarsLoader
+{
+    private readonly DirectoryInfo directory;
+
+    private readonly string pattern;
+
+    public FileSystemHandlebarsTemplateLoader(
+        DirectoryInfo directory,
+        string pattern = "*.hbs")
+    {
+        this.directory = directory;
+        this.pattern = pattern;
+    }
+
+    /// <inheritdoc />
+    public void Register(IHandlebars handlebars)
+    {
+        foreach (FileInfo file in this.directory.GetFiles(this.pattern))
+        {
+            string name = Path.GetFileNameWithoutExtension(file.Name);
+            string content = File.ReadAllText(file.FullName);
+
+            handlebars.RegisterTemplate(name, content);
+        }
+    }
+}

src/Nitride.Handlebars/Configuration/ForEachHandlebarsBlock.cs

@@ -0,0 +1,95 @@
+using System;
+using System.Collections.Generic;
+
+using HandlebarsDotNet;
+
+namespace Nitride.Handlebars.Configuration;
+
+/// <summary>
+/// </summary>
+/// <typeparam name="TModel">A typesafe model of the template.</typeparam>
+public class ForEachHandlebarsBlock<TModel> : HandlebarsBlockBase
+{
+    public ForEachHandlebarsBlock(string helperName)
+    {
+        this.HelperName = helperName;
+    }
+
+    /// <summary>
+    /// Gets or sets the list that needs to be rendered.
+    /// </summary>
+    public Func<TModel, IEnumerable<object>>? GetList { get; set; }
+
+    /// <summary>
+    /// Gets or sets the callback that is called when nothing is found.
+    /// </summary>
+    public Action<EncodedTextWriter, BlockHelperOptions, Context, Arguments>? NothingFound { get; set; }
+
+    /// <inheritdoc />
+    protected override string HelperName { get; }
+
+    public ForEachHandlebarsBlock<TModel> WithGetList(Func<TModel, IEnumerable<object>>? callback)
+    {
+        this.GetList = callback;
+
+        return this;
+    }
+
+    public ForEachHandlebarsBlock<TModel> WithNothingFoundText(
+        Action<EncodedTextWriter, BlockHelperOptions, Context, Arguments>? callback)
+    {
+        this.NothingFound = callback;
+
+        return this;
+    }
+
+    /// <summary>
+    /// Sets the output to write out text when no items are found.
+    /// </summary>
+    /// <param name="text">The text to write out.</param>
+    /// <returns>The same object for chained methods.</returns>
+    public ForEachHandlebarsBlock<TModel> WithNothingFoundText(string text)
+    {
+        this.NothingFound = (
+            output,
+            _1,
+            _2,
+            _3) => output.Write(text);
+
+        return this;
+    }
+
+    /// <inheritdoc />
+    protected override void Render(
+        EncodedTextWriter output,
+        BlockHelperOptions options,
+        Context context,
+        Arguments input)
+    {
+        if (context.Value is not TModel model)
+        {
+            throw new InvalidOperationException(
+                string.Format(
+                    "Cannot apply the {0} on context value because it is {1}.",
+                    nameof(ForEachHandlebarsBlock<TModel>),
+                    context.Value.GetType()));
+        }
+
+        IEnumerable<object>? list = this.GetList?.Invoke(model);
+        bool hasItems = false;
+
+        if (list != null)
+        {
+            foreach (object item in list)
+            {
+                hasItems = true;
+                options.Template(output, item);
+            }
+        }
+
+        if (!hasItems)
+        {
+            this.NothingFound?.Invoke(output, options, context, input);
+        }
+    }
+}

src/Nitride.Handlebars/Configuration/HandlebarsBlockBase.cs

@@ -0,0 +1,30 @@
+using HandlebarsDotNet;
+
+namespace Nitride.Handlebars.Configuration;
+
+/// <summary>
+/// Describes a block helper which can be registered.
+/// </summary>
+public abstract class HandlebarsBlockBase : IHandlebarsLoader
+{
+    /// <summary>
+    /// Gets the name of the helper, which is how it is called in the template.
+    /// </summary>
+    protected abstract string HelperName { get; }
+
+    public void Register(IHandlebars handlebars)
+    {
+        HandlebarsBlockHelper blockHelper = this.Render;
+
+        handlebars.RegisterHelper(this.HelperName, blockHelper);
+    }
+
+    /// <summary>
+    /// Renders the helper to the template.
+    /// </summary>
+    protected abstract void Render(
+        EncodedTextWriter output,
+        BlockHelperOptions options,
+        Context context,
+        Arguments input);
+}

src/Nitride.Handlebars/Configuration/IHandlebarsLoader.cs

@@ -0,0 +1,15 @@
+using HandlebarsDotNet;
+
+namespace Nitride.Handlebars.Configuration;
+
+/// <summary>
+/// Describes a dependency injected loader of templates or modules.
+/// </summary>
+public interface IHandlebarsLoader
+{
+    /// <summary>
+    /// Registers the given helper into the handlebars engine.
+    /// </summary>
+    /// <param name="handlebars">The handlebars to register the helper into.</param>
+    void Register(IHandlebars handlebars);
+}

src/Nitride.Handlebars/NitrideHandlebarsBuilderExtensions.cs

@@ -1,11 +1,39 @@
+using System;
+using System.Collections.Generic;
+
 using Autofac;
 
+using Nitride.Handlebars.Configuration;
+
 namespace Nitride.Handlebars;
 
 public static class NitrideHandlebarsBuilderExtensions
 {
     public static NitrideBuilder UseHandlebars(this NitrideBuilder builder)
     {
-        return builder.ConfigureContainer(x => x.RegisterModule<NitrideHandlebarsModule>());
+        return builder
+            .ConfigureContainer(x => x.RegisterModule<NitrideHandlebarsModule>());
+    }
+
+    public static NitrideBuilder UseHandlebars(
+        this NitrideBuilder builder,
+        Func<ContainerBuilder, IEnumerable<IHandlebarsLoader>> configure)
+    {
+        builder.UseHandlebars();
+
+        builder.ConfigureContainer(
+            c =>
+            {
+                IEnumerable<IHandlebarsLoader> loaders = configure(c);
+
+                foreach (IHandlebarsLoader loader in loaders)
+                {
+                    c.RegisterInstance(loader)
+                        .As<IHandlebarsLoader>()
+                        .SingleInstance();
+                }
+            });
+
+        return builder;
     }
 }

src/Nitride.Handlebars/NitrideHandlebarsModule.cs

@@ -1,5 +1,11 @@
+using System.Collections.Generic;
+
 using Autofac;
 
+using HandlebarsDotNet;
+
+using Nitride.Handlebars.Configuration;
+
 namespace Nitride.Handlebars;
 
 public class NitrideHandlebarsModule : Module
@@ -14,10 +20,20 @@ public class NitrideHandlebarsModule : Module
             .AsSelf()
             .SingleInstance();
 
-        builder.RegisterGeneric(typeof(RenderContentTemplate<>))
-            .As(typeof(RenderContentTemplate<>));
+        builder.Register(
+                (context) =>
+                {
+                    IHandlebars handlebars = HandlebarsDotNet.Handlebars.Create();
+                    IEnumerable<IHandlebarsLoader> helpers = context.Resolve<IEnumerable<IHandlebarsLoader>>();
 
-        builder.RegisterGeneric(typeof(ApplyStyleTemplate<>))
-            .As(typeof(ApplyStyleTemplate<>));
+                    foreach (IHandlebarsLoader helper in helpers)
+                    {
+                        helper.Register(handlebars);
+                    }
+
+                    return handlebars;
+                })
+            .As<IHandlebars>()
+            .SingleInstance();
     }
 }

src/Nitride.Handlebars/RenderContentTemplate.cs

@@ -16,18 +16,18 @@ namespace Nitride.Handlebars;
 /// applied against the content and metadata and then replaces the content
 /// of that entity.
 /// </summary>
-public class RenderContentTemplate<TModel> : OperationBase
+[WithProperties]
+public partial class RenderContentTemplate : OperationBase
 {
     private readonly HandlebarsTemplateCache cache;
 
-    // TODO: This does not use [WithProperties] because the source generator hasn't been taught how to do generics.
+    private readonly IValidator<RenderContentTemplate> validator;
 
-    private readonly IValidator<RenderContentTemplate<TModel>> validator;
-
-    public RenderContentTemplate(HandlebarsTemplateCache cache)
+    public RenderContentTemplate(
+        IValidator<RenderContentTemplate> validator,
+        HandlebarsTemplateCache cache)
     {
-        // TODO: Figure out why Autofac won't let us register IValidator of generic classes.
-        this.validator = new RenderContentTemplateValidator<TModel>();
+        this.validator = validator;
         this.cache = cache;
     }
 
@@ -36,7 +36,7 @@ public class RenderContentTemplate<TModel> : OperationBase
     /// entity. This allows for the website to customize what information is
     /// being passed to the template.
     /// </summary>
-    public Func<Entity, TModel>? CreateModelCallback { get; set; }
+    public Func<Entity, object>? CreateModelCallback { get; set; }
 
     /// <inheritdoc />
     public override IEnumerable<Entity> Run(IEnumerable<Entity> input)
@@ -46,36 +46,18 @@ public class RenderContentTemplate<TModel> : OperationBase
         return input.SelectEntity<HasHandlebarsTemplate, ITextContent>(this.Apply);
     }
 
-    /// <summary>
-    /// Sets the callback for the template and returns the operation to
-    /// chain operations.
-    /// </summary>
-    /// <param name="callback">The callback to set.</param>
-    /// <returns>The ApplyContentHandlebarsTemplate to chain requests.</returns>
-    public RenderContentTemplate<TModel> WithCreateModelCallback(Func<Entity, TModel>? callback)
-    {
-        this.CreateModelCallback = callback;
-
-        return this;
-    }
-
     private Entity Apply(
         Entity entity,
         HasHandlebarsTemplate _,
         ITextContent content)
     {
-        // Create the model using the callback.
-        TModel model = this.CreateModelCallback!(entity);
-
-        // Create a template from the contents.
         string text = content.GetText();
         HandlebarsTemplate<object, object> template = this.cache.GetLiteralTemplate(text);
-
-        // Render the template and create a new entity with the updated
-        // text.
+        object model = this.CreateModelCallback!(entity);
         string result = template(model!);
 
-        return entity.Remove<HasHandlebarsTemplate>()
-            .SetTextContent(new StringTextContent(result));
+        return entity
+            .Remove<HasHandlebarsTemplate>()
+            .SetTextContent(result);
     }
 }

src/Nitride.Handlebars/RenderContentTemplateValidator.cs

@@ -2,7 +2,7 @@ using FluentValidation;
 
 namespace Nitride.Handlebars;
 
-public class RenderContentTemplateValidator<TModel> : AbstractValidator<RenderContentTemplate<TModel>>
+public class RenderContentTemplateValidator : AbstractValidator<RenderContentTemplate>
 {
     public RenderContentTemplateValidator()
     {

src/Nitride/NitrideBuilder.cs

@@ -92,7 +92,8 @@ public class NitrideBuilder
                 "Application name must be set, such as with the NitrideBuilder.WithApplicationName() to properly run.");
         }
 
-        return await ToolBoxBuilder.Create(this.nitrideModule.ApplicationName, this.arguments)
+        return await ToolBoxBuilder
+            .Create(this.nitrideModule.ApplicationName, this.arguments)
             .ConfigureContainer(this.ConfigureContainer)
             .Build()
             .RunAsync();