From 36e764d07b4fa106b5e43db24d74134bd4cd1118 Mon Sep 17 00:00:00 2001
From: Vladimir Enchev <vladimir.enchev@gmail.com>
Date: Wed, 24 Jun 2026 13:52:31 +0300
Subject: [PATCH] Online demos: support C# 12+ syntax and preserve more trimmed
 types

Two follow-up fixes for compiling demos in Edit Source / Playground:

- CompilerService: raise the parse language version from C# 10 to Latest
  so demos using collection expressions and primary constructors compile
  (previously failed with CS8936).
- linker.xml: preserve System.Math, DisplayAttribute and Radzen.Colors,
  which are referenced only by demo source compiled at runtime and were
  otherwise removed by trimming (Math.PI, [Display(Description=...)],
  @Colors.* respectively).

Verified against a trimmed publish: demo compile failures drop from 20 to 5
out of 1052 (remaining 5 are a separate Razor type-inference codegen issue).
---
 RadzenBlazorDemos/Services/CompilerService.cs |  2 +-
 RadzenBlazorDemos/linker.xml                  | 10 ++++++++++
 2 files changed, 11 insertions(+), 1 deletion(-)

diff --git a/RadzenBlazorDemos/Services/CompilerService.cs b/RadzenBlazorDemos/Services/CompilerService.cs
index f36d7108c..e28494bc3 100644
--- a/RadzenBlazorDemos/Services/CompilerService.cs
+++ b/RadzenBlazorDemos/Services/CompilerService.cs
@@ -196,7 +196,7 @@ namespace RadzenBlazorDemos
                 .Replace("#nullable enable", "#nullable disable")
                 .Replace("where TItem : , notnull", "where TItem : notnull");
 
-            var syntaxTree = CSharpSyntaxTree.ParseText(generatedCode, CSharpParseOptions.Default.WithLanguageVersion(LanguageVersion.CSharp10));
+            var syntaxTree = CSharpSyntaxTree.ParseText(generatedCode, CSharpParseOptions.Default.WithLanguageVersion(LanguageVersion.Latest));
 
             compilation = compilation.RemoveAllSyntaxTrees().AddSyntaxTrees(syntaxTree);
 
diff --git a/RadzenBlazorDemos/linker.xml b/RadzenBlazorDemos/linker.xml
index 5aa037bd0..b8cc68b7a 100644
--- a/RadzenBlazorDemos/linker.xml
+++ b/RadzenBlazorDemos/linker.xml
@@ -8,5 +8,15 @@
 	</assembly>
 	<!-- The runtime Razor/Roslyn compiler behind Edit Source / Playground relies on the [EventHandler] metadata (e.g. oninput -> ChangeEventArgs) on Microsoft.AspNetCore.Components.Web.EventHandlers to recognize event attributes. Trimming removes that compile-time-only class, so handlers like @oninput=@(args => ...) become literal attributes and fail with CS1660 "Cannot convert lambda expression to type 'bool'". Preserve the assembly so demos compile online. -->
 	<assembly fullname="Microsoft.AspNetCore.Components.Web" preserve="all"/>
+	<!-- The following types are referenced only by demo source compiled at runtime (Edit Source / Playground), so trimming removes members the runtime compiler needs. Preserve them so those demos compile online. -->
+	<assembly fullname="System.Private.CoreLib">
+		<type fullname="System.Math" preserve="all"/>
+	</assembly>
+	<assembly fullname="System.ComponentModel.Annotations">
+		<type fullname="System.ComponentModel.DataAnnotations.DisplayAttribute" preserve="all"/>
+	</assembly>
+	<assembly fullname="Radzen.Blazor">
+		<type fullname="Radzen.Colors" preserve="all"/>
+	</assembly>
 </linker>