Allow pages to add custom stylesheets and scripts

Author: Kaliumhexacyanoferrat

API/Content/IPageAdditionBuilder.cs

@@ -0,0 +1,13 @@
+namespace GenHTTP.Api.Content
+{
+
+    public interface IPageAdditionBuilder<out T>
+    {
+
+        T AddScript(string path, bool asynchronous = false);
+
+        T AddStyle(string path);
+
+    }
+
+}

API/Content/PageAdditionBuilder.cs

@@ -0,0 +1,28 @@
+using GenHTTP.Api.Infrastructure;
+
+namespace GenHTTP.Api.Content
+{
+
+    public class PageAdditionBuilder : IBuilder<PageAdditions?>, IPageAdditionBuilder<PageAdditionBuilder>
+    {
+        private PageAdditions? _Additions;
+
+        public PageAdditionBuilder AddScript(string path, bool asynchronous = false)
+        {
+            EnsureAdditions().Scripts.Add(new(path, asynchronous));
+            return this;
+        }
+
+        public PageAdditionBuilder AddStyle(string path)
+        {
+            EnsureAdditions().Styles.Add(new(path));
+            return this;
+        }
+
+        private PageAdditions EnsureAdditions() => _Additions ?? (_Additions = PageAdditions.Create());
+
+        public PageAdditions? Build() => _Additions;
+
+    }
+
+}

API/Content/PageAdditions.cs

@@ -0,0 +1,22 @@
+using System.Collections.Generic;
+
+using GenHTTP.Api.Content.Websites;
+
+namespace GenHTTP.Api.Content
+{
+
+    public record PageAdditions
+    (
+
+        List<StyleReference> Styles,
+
+        List<ScriptReference> Scripts
+
+    )
+    {
+
+        public static PageAdditions Create() => new(new(), new());
+
+    }
+
+}

API/Content/Templating/TemplateModel.cs

@@ -1,6 +1,6 @@
 using System.Threading.Tasks;
-
 using GenHTTP.Api.Protocol;
+using static System.Net.WebRequestMethods;
 
 namespace GenHTTP.Api.Content.Templating
 {
@@ -19,6 +19,12 @@ public sealed class TemplateModel : AbstractModel
         /// </summary>
         public ContentInfo Meta { get; }
 
+        /// <summary>
+        /// Additional references to styles or scripts to be included
+        /// when rendering the template.
+        /// </summary>
+        public PageAdditions? Additions { get; }
+
         /// <summary>
         /// The HTML content to be rendered within the template.
         /// </summary>
@@ -34,11 +40,14 @@ public sealed class TemplateModel : AbstractModel
         /// <param name="request">The request which caused this call</param>
         /// <param name="handler">The handler responsible to render the response</param>
         /// <param name="pageInfo">Information about the page to be rendered</param>
+        /// <param name="additions">Additional references to required scripts or styles</param>
         /// <param name="content">The content to be rendered within the template</param>
-        public TemplateModel(IRequest request, IHandler handler, ContentInfo pageInfo, string content) : base(request, handler)
+        public TemplateModel(IRequest request, IHandler handler, ContentInfo pageInfo, PageAdditions? additions, string content) : base(request, handler)
         {
             Content = content;
 
+            Additions = additions;
+
             Meta = pageInfo;
 
             if (string.IsNullOrEmpty(Meta.Title))

Engine/Infrastructure/CoreRouter.cs

@@ -1,6 +1,7 @@
 using System;
 using System.Collections.Generic;
 using System.IO;
+using System.Text;
 using System.Threading.Tasks;
 
 using GenHTTP.Api.Content;
@@ -9,6 +10,7 @@
 
 using GenHTTP.Modules.IO;
 using GenHTTP.Modules.Placeholders;
+using GenHTTP.Modules.Basics;
 
 namespace GenHTTP.Engine.Infrastructure
 {
@@ -51,6 +53,7 @@ internal CoreRouter(IHandlerBuilder content, IEnumerable<IConcernBuilder> concer
             Content = Concerns.Chain(this, concerns, (p) => content.Build(p));
 
             Template = Placeholders.Template<TemplateModel>(Resource.FromAssembly("Template.html"))
+                                   .AddRenderer("additions", (model, a) => RenderAdditions(model, (PageAdditions?)a))
                                    .Build();
 
             ErrorRenderer = Placeholders.Template<ErrorModel>(Resource.FromAssembly(development ? "ErrorStacked.html" : "Error.html"))
@@ -86,6 +89,26 @@ public async ValueTask PrepareAsync()
 
         public ValueTask RenderAsync(TemplateModel model, Stream target) => Template.RenderAsync(model, target);
 
+        private string RenderAdditions(IModel model, PageAdditions? additions)
+        {
+            var builder = new StringBuilder();
+
+            if (additions != null)
+            {
+                foreach (var style in additions.Styles)
+                {
+                    builder.AppendLine($"<link rel=\"stylesheet\" href=\"{model.Handler.Route(model.Request, style.Path)}\" />");
+                }
+
+                foreach (var script in additions.Scripts)
+                {
+                    builder.AppendLine($"<script src=\"{model.Handler.Route(model.Request, script.Path)}\"></script>");
+                }
+            }
+
+            return builder.ToString();
+        }
+
         #endregion
 
     }

Engine/Resources/Template.html

@@ -70,6 +70,8 @@
 
     </style>
 
+    [additions]
+
 </head>
 
 <body>

Modules/Authentication.Web/Concern/WebAuthenticationConcern.cs

@@ -27,6 +27,8 @@ public sealed class WebAuthenticationConcern : IConcern, IRootPathAppender, IHan
 
         private IHandler SetupHandler { get; }
 
+        private IHandler ResourceHandler { get; }
+
         #endregion
 
         #region Initialization
@@ -42,6 +44,8 @@ public WebAuthenticationConcern(IHandler parent, Func<IHandler, IHandler> conten
 
             LoginHandler = integration.LoginHandler.Build(this);
             SetupHandler = integration.SetupHandler.Build(this);
+
+            ResourceHandler = integration.ResourceHandler.Build(this);
         }
 
         #endregion
@@ -56,6 +60,13 @@ public WebAuthenticationConcern(IHandler parent, Func<IHandler, IHandler> conten
         {
             var segment = request.Target.Current;
 
+            if (segment?.Value == Integration.ResourceRoute)
+            {
+                request.Target.Advance();
+
+                return await ResourceHandler.HandleAsync(request).ConfigureAwait(false);
+            }
+
             if (await Integration.CheckSetupRequired(request).ConfigureAwait(false))
             {
                 if (segment?.Value != Integration.SetupRoute)
@@ -161,6 +172,11 @@ public void Append(PathBuilder path, IRequest request, IHandler? child = null)
             {
                 path.Preprend(Integration.SetupRoute);
             }
+
+            if (child == ResourceHandler)
+            {
+                path.Preprend(Integration.ResourceRoute);
+            }
         }
 
         public IHandler? Find(string segment)
@@ -180,6 +196,11 @@ public void Append(PathBuilder path, IRequest request, IHandler? child = null)
                 return SetupHandler;
             }
 
+            if (segment == "{web-auth-resources}")
+            {
+                return ResourceHandler;
+            }
+
             return null;
         }
 

Modules/Authentication.Web/Controllers/BaseController.cs

@@ -0,0 +1,22 @@
+using GenHTTP.Api.Content;
+using GenHTTP.Api.Content.Templating;
+
+using GenHTTP.Modules.IO;
+using GenHTTP.Modules.Razor;
+
+namespace GenHTTP.Modules.Authentication.Web.Controllers
+{
+
+    public class BaseController
+    {
+
+        protected IHandlerBuilder RenderAccountEntry(string title)
+        {
+            return ModRazor.Page(Resource.FromAssembly("EnterAccount.cshtml"), (r, h) => new BasicModel(r, h))
+                           .AddStyle("{web-auth-resources}/style.css")
+                           .Title(title);
+        }
+
+    }
+
+}

Modules/Authentication.Web/Controllers/LoginController.cs

@@ -3,30 +3,28 @@
 
 using GenHTTP.Api.Content;
 using GenHTTP.Api.Content.Authentication;
-using GenHTTP.Api.Content.Templating;
 using GenHTTP.Api.Protocol;
+
 using GenHTTP.Modules.Basics;
 using GenHTTP.Modules.Controllers;
-using GenHTTP.Modules.IO;
-using GenHTTP.Modules.Razor;
 
 namespace GenHTTP.Modules.Authentication.Web.Controllers
 {
-    
-    public class LoginController
+
+    public class LoginController : BaseController
     {
 
         private Func<IRequest, string, string, ValueTask<IUser?>> PerformLogin { get; }
 
-        public LoginController(Func<IRequest, string, string, ValueTask<IUser?>> performLogin) 
+        public LoginController(Func<IRequest, string, string, ValueTask<IUser?>> performLogin)
         {
             PerformLogin = performLogin;
         }
 
         public IHandlerBuilder Index()
         {
             // ToDo: already logged in
-            return RenderLogin();
+            return RenderAccountEntry("Login");
         }
 
         [ControllerAction(RequestMethod.POST)]
@@ -42,16 +40,10 @@ public async Task<IHandlerBuilder> Index(string user, string password, IRequest
             }
             else
             {
-                return RenderLogin();
+                return RenderAccountEntry("Login");
             }
         }
 
-        private static IHandlerBuilder RenderLogin()
-        {
-            return ModRazor.Page(Resource.FromAssembly("EnterAccount.cshtml"), (r, h) => new BasicModel(r, h))
-                           .Title("Login");
-        }
-
     }
 
 }

Modules/Authentication.Web/Controllers/SetupController.cs

@@ -13,7 +13,7 @@
 namespace GenHTTP.Modules.Authentication.Web.Controllers
 {
 
-    public sealed class SetupController
+    public sealed class SetupController : BaseController
     {
 
         private Func<IRequest, string, string, ValueTask> PerformSetup { get; }
@@ -25,8 +25,7 @@ public SetupController(Func<IRequest, string, string, ValueTask> performSetup)
 
         public IHandlerBuilder Index()
         {
-            return ModRazor.Page(Resource.FromAssembly("EnterAccount.cshtml"), (r, h) => new BasicModel(r, h))
-                           .Title("Setup");
+            return RenderAccountEntry("Setup");
         }
 
         [ControllerAction(RequestMethod.POST)]