Add custom attributes

Author: andrewlock

BlazorPreRender/BlazorApp1/BlazorApp1/Pages/Counter.razor

@@ -1,5 +1,5 @@
 @page "/counter"
-@attribute [System.ComponentModel.Description("Counter")]
+@attribute [MenuItem("oi-plus", "Counter")]
 
 <h1>Counter</h1>
 

BlazorPreRender/BlazorApp1/BlazorApp1/Pages/Example.razor

@@ -1,4 +1,4 @@
 @page "/Example"
-@attribute [System.ComponentModel.Description("Example")]
+@attribute [MenuItem("oi-list-rich", "Example")]
 
 <h3>Example</h3>

BlazorPreRender/BlazorApp1/BlazorApp1/Pages/Index.razor

@@ -1,5 +1,5 @@
 @page "/"
-@attribute [System.ComponentModel.Description("Home")]
+@attribute [MenuItem("oi-home", "Home", order: int.MinValue)]
 
 <h1>Hello, world!</h1>
 

BlazorPreRender/BlazorApp1/BlazorApp1/Shared/NavMenu.razor

@@ -11,7 +11,7 @@
         {
             <li class="nav-item px-3">
                 <NavLink class="nav-link" href="@pageDetail.Route" Match="NavLinkMatch.All">
-                    @pageDetail.Title
+                    <span class="oi @pageDetail.Icon" aria-hidden="true"></span> @pageDetail.Title
                 </NavLink>
             </li>    
         }

BlazorPreRender/BlazorApp1/SourceGenerators/PageDetailsGenerator.cs

@@ -15,17 +15,17 @@ namespace SourceGenerators
     public class PageDetailsGenerator : ISourceGenerator
     {
         private const string RouteAttributeName = "Microsoft.AspNetCore.Components.RouteAttribute";
-        private const string DescriptionAttributeName = "System.ComponentModel.Description";
+        private const string MenuItemAttributeName = "MenuItem";
 
         public void Execute(GeneratorExecutionContext context)
         {
             try
             {
-                // Debugger.Launch();
 
                 IEnumerable<RouteableComponent> menuComponents = GetMenuComponents(context.Compilation);
 
                 context.AddSource("PageDetail", SourceText.From(Templates.PageDetail(), Encoding.UTF8));
+                context.AddSource("MenuItemAttribute", SourceText.From(Templates.MenuItemAttribute(), Encoding.UTF8));
                 var pageDetailsSource = SourceText.From(Templates.MenuPages(menuComponents), Encoding.UTF8);
                 context.AddSource("PageDetails", pageDetailsSource);
             }
@@ -47,11 +47,13 @@ private static ImmutableArray<RouteableComponent> GetMenuComponents(Compilation
             IEnumerable<ClassDeclarationSyntax> allClasses = allNodes
                 .Where(d => d.IsKind(SyntaxKind.ClassDeclaration))
                 .OfType<ClassDeclarationSyntax>();
-            
+
             return allClasses
                 .Select(component => TryGetMenuComponent(compilation, component))
                 .Where(page => page is not null)
-                .Cast<RouteableComponent>()// stops the nullable lies
+                .Cast<RouteableComponent>() // stops the nullable lies
+                .OrderBy(x => x.Order)
+                .ThenBy(x => x.Title)
                 .ToImmutableArray();
         }
 
@@ -61,20 +63,20 @@ private static ImmutableArray<RouteableComponent> GetMenuComponents(Compilation
                 .SelectMany(x => x.Attributes)
                 .Where(attr => 
                     attr.Name.ToString() == RouteAttributeName
-                    || attr.Name.ToString() == DescriptionAttributeName)
+                    || attr.Name.ToString() == MenuItemAttributeName)
                 .ToList();
 
             var routeAttribute = attributes.FirstOrDefault(attr => attr.Name.ToString() == RouteAttributeName);
-            var descriptionAttribute = attributes.FirstOrDefault(attr => attr.Name.ToString() == DescriptionAttributeName);
+            var menuItemAttribute = attributes.FirstOrDefault(attr => attr.Name.ToString() == MenuItemAttributeName);
 
-            if (routeAttribute is null || descriptionAttribute is null)
+            if (routeAttribute is null || menuItemAttribute is null)
             {
                 return null;
             }
 
             if (
                 routeAttribute.ArgumentList?.Arguments.Count != 1 ||
-                descriptionAttribute.ArgumentList?.Arguments.Count != 1)
+                menuItemAttribute.ArgumentList?.Arguments.Count < 2)
             {
                 // no route path or description value
                 return null;
@@ -86,11 +88,27 @@ private static ImmutableArray<RouteableComponent> GetMenuComponents(Compilation
             var routeExpr = routeArg.Expression;
             var routeTemplate = semanticModel.GetConstantValue(routeExpr).ToString();
 
-            var descriptionArg = descriptionAttribute.ArgumentList.Arguments[0];
+            var iconArg = menuItemAttribute.ArgumentList.Arguments[0];
+            var iconExpr = iconArg.Expression;
+            var icon = semanticModel.GetConstantValue(iconExpr).ToString();
+            
+            var descriptionArg = menuItemAttribute.ArgumentList.Arguments[1];
             var descriptionExpr = descriptionArg.Expression;
             var title = semanticModel.GetConstantValue(descriptionExpr).ToString();
 
-            return new RouteableComponent(routeTemplate, title);
+            var order = 0;
+            if (menuItemAttribute.ArgumentList?.Arguments.Count == 3)
+            {
+                var orderArg = menuItemAttribute.ArgumentList.Arguments[2];
+                var orderExpr = orderArg.Expression;
+                var maybeOrder = semanticModel.GetConstantValue(orderExpr);
+                if (maybeOrder.HasValue)
+                {
+                    order = (int) maybeOrder.Value;
+                }
+            }
+            
+            return new RouteableComponent(routeTemplate, title, icon, order);
         }
     }
 }

BlazorPreRender/BlazorApp1/SourceGenerators/RouteableComponent.cs

@@ -4,10 +4,14 @@ public class RouteableComponent
     {
         public string Route { get; }
         public string Title { get; }
+        public string Icon { get; }
+        public int Order { get; }
 
-        public RouteableComponent(string route, string title)
+        public RouteableComponent(string route, string title, string icon, int order)
         {
             Title = title;
+            Icon = icon;
+            Order = order;
             Route = route;
         }
     }

BlazorPreRender/BlazorApp1/SourceGenerators/Templates.cs

@@ -39,7 +39,33 @@ public static string PageDetail()
             return @"
 namespace BlazorApp1
 {
-    public record PageDetail(string Route, string Title);
+    public record PageDetail(string Route, string Title, string Icon);
+}
+";
+        }
+
+        public static string MenuItemAttribute()
+        {
+            return @"
+namespace BlazorApp1
+{
+    public class MenuItemAttribute : System.Attribute
+    {
+        public string Icon { get; }
+        public string Description { get; }
+        public int Order { get; }
+
+        public MenuItemAttribute(
+            string icon,
+            string description,
+            int order = 0
+        )
+        {
+            Icon = icon;
+            Description = description;
+            Order = order;
+        }
+    }
 }
 ";
         }
@@ -62,7 +88,7 @@ public static class PageDetails
 ");
             foreach (var page in pages)
             {
-                sb.AppendLine($"new PageDetail(\"{page.Route}\", \"{page.Title}\"),");
+                sb.AppendLine($"new PageDetail(\"{page.Route}\", \"{page.Title}\", \"{page.Icon}\"),");
             }
 
             sb.Append(@"