Refactored markup file loader to be extensible by third-party libraries

src/Framework/Framework/DependencyInjection/DotVVMServiceCollectionExtensions.cs

@@ -63,6 +63,8 @@ public static IServiceCollection RegisterDotVVMServices(IServiceCollection servi
             services.TryAddSingleton<IOutputRenderer, DefaultOutputRenderer>();
             services.TryAddSingleton<IDotvvmPresenter, DotvvmPresenter>();
             services.TryAddSingleton<IMarkupFileLoader, AggregateMarkupFileLoader>();
+            services.TryAddSingleton<DefaultMarkupFileLoader>();
+            services.TryAddSingleton<EmbeddedMarkupFileLoader>();
             services.TryAddSingleton<IControlBuilderFactory, DefaultControlBuilderFactory>();
             services.TryAddSingleton<IControlResolver, DefaultControlResolver>();
             services.TryAddSingleton<IControlTreeResolver, DefaultControlTreeResolver>();

src/Framework/Framework/Hosting/AggregateMarkupFileLoader.cs

@@ -3,28 +3,30 @@
 using System.Linq;
 using System.Text;
 using DotVVM.Framework.Configuration;
+using Microsoft.Extensions.DependencyInjection;
+using Microsoft.Extensions.Options;
 
 namespace DotVVM.Framework.Hosting
 {
     public class AggregateMarkupFileLoader : IMarkupFileLoader
     {
-        public List<IMarkupFileLoader> Loaders { get; private set; } = new List<IMarkupFileLoader>();
+        private readonly List<IMarkupFileLoader> loaders;
 
-        public AggregateMarkupFileLoader()
+        public AggregateMarkupFileLoader(IOptions<AggregateMarkupFileLoaderOptions> options, IServiceProvider serviceProvider)
         {
-            // the EmbeddedMarkupFileLoader must be registered before DefaultMarkupFileLoader (which gets wrapped by HotReloadMarkupFileLoader)
-            Loaders.Add(new EmbeddedMarkupFileLoader());
-            Loaders.Add(new DefaultMarkupFileLoader());
+            loaders = options.Value.LoaderTypes
+                .Select(p => (IMarkupFileLoader)serviceProvider.GetRequiredService(p))
+                .ToList();
         }
 
         /// <summary>
         /// Gets the markup file for the specified virtual path.
         /// </summary>
         public MarkupFile? GetMarkup(DotvvmConfiguration configuration, string virtualPath)
         {
-            for (int i = 0; i < Loaders.Count; i++)
+            for (var i = 0; i < loaders.Count; i++)
             {
-                var result = Loaders[i].GetMarkup(configuration, virtualPath);
+                var result = loaders[i].GetMarkup(configuration, virtualPath);
                 if (result != null)
                 {
                     return result;

src/Framework/Framework/Hosting/AggregateMarkupFileLoaderOptions.cs

@@ -0,0 +1,19 @@
+using System;
+using System.Collections.Generic;
+
+namespace DotVVM.Framework.Hosting;
+
+public class AggregateMarkupFileLoaderOptions
+{
+    public List<Type> LoaderTypes { get; }
+
+    public AggregateMarkupFileLoaderOptions()
+    {
+        LoaderTypes = new()
+        {
+            // the EmbeddedMarkupFileLoader must be registered before DefaultMarkupFileLoader (which gets wrapped by HotReloadMarkupFileLoader)
+            typeof(EmbeddedMarkupFileLoader),
+            typeof(DefaultMarkupFileLoader)
+        };
+    }
+}

src/Framework/Framework/Hosting/MarkupFile.cs

@@ -67,7 +67,7 @@ public MarkupFile(string fileName, string fullPath)
             };
         }
 
-        internal MarkupFile(string fileName, string fullPath, string contents)
+        public MarkupFile(string fileName, string fullPath, string contents)
         {
             FileName = fileName;
             FullPath = fullPath;

src/Tools/HotReload/AspNetCore/Configuration/DotvvmServiceCollectionExtensions.cs

@@ -20,7 +20,17 @@ public static void AddHotReload(this IDotvvmServiceCollection services)
             services.Services.AddSignalR();
 
             services.Services.AddSingleton<IMarkupFileChangeNotifier, AspNetCoreMarkupFileChangeNotifier>();
-            services.Services.AddSingleton<IMarkupFileLoader, HotReloadAggregateMarkupFileLoader>();
+            services.Services.Configure<AggregateMarkupFileLoaderOptions>(options =>
+            {
+                var index = options.LoaderTypes.FindIndex(l => l == typeof(DefaultMarkupFileLoader));
+                if (index < 0)
+                {
+                    throw new InvalidOperationException("DotVVM Hot reload could not be initialized - the DefaultMarkupLoader was not found in the AggregateMarkupFileLoader Loaders collection.");
+                }
+
+                options.LoaderTypes[index] = typeof(HotReloadMarkupFileLoader);
+            });
+            services.Services.AddSingleton<HotReloadMarkupFileLoader>();
 
             services.Services.Configure<DotvvmConfiguration>(RegisterResources);
             services.Services.AddTransient<ResourceManager>(provider =>

src/Tools/HotReload/Owin/Configuration/DotvvmServiceCollectionExtensions.cs

@@ -19,7 +19,16 @@ public static class DotvvmServiceCollectionExtensions
         public static void AddHotReload(this IDotvvmServiceCollection services, DotvvmHotReloadOptions? options = null)
         {
             services.Services.AddSingleton<IMarkupFileChangeNotifier, OwinMarkupFileChangeNotifier>();
-            services.Services.AddSingleton<IMarkupFileLoader, HotReloadAggregateMarkupFileLoader>();
+            services.Services.Configure<AggregateMarkupFileLoaderOptions>(options => {
+                var index = options.LoaderTypes.FindIndex(l => l == typeof(DefaultMarkupFileLoader));
+                if (index < 0)
+                {
+                    throw new InvalidOperationException("DotVVM Hot reload could not be initialized - the DefaultMarkupLoader was not found in the AggregateMarkupFileLoader Loaders collection.");
+                }
+
+                options.LoaderTypes[index] = typeof(HotReloadMarkupFileLoader);
+            });
+            services.Services.AddSingleton<HotReloadMarkupFileLoader>();
 
             services.Services.Configure<DotvvmConfiguration>(config => RegisterResources(config, options ?? new DotvvmHotReloadOptions()));
             services.Services.AddTransient<ResourceManager>(provider =>