Make links clickable in Markdown Preview for Docs

Remove extra blank entry for empty text after last sample
Fix template text for Markdown display

Author: michael-hawker

common/CommunityToolkit.Labs.Shared/Renderers/Markdown/MarkdownTextBlock.cs

@@ -23,4 +23,15 @@ namespace CommunityToolkit.Labs.Shared.Renderers;
 /// </summary>
 public partial class MarkdownTextBlock : ToolkitMTB
 {
+#if HAS_UNO
+    //// Polyfill dummy for event callback
+    #pragma warning disable CS0067 // Unused on purpose for polyfill
+    public event EventHandler<LinkClickedEventArgs>? LinkClicked;
+    #pragma warning restore CS0067 // Unused on purpose for polyfill
+#endif
 }
+
+#if HAS_UNO
+//// Polyfill dummy for event callback
+public class LinkClickedEventArgs : EventArgs { }
+#endif

common/CommunityToolkit.Labs.Shared/Renderers/ToolkitDocumentationRenderer.xaml

@@ -17,6 +17,7 @@
         <DataTemplate x:Key="DocumentTemplate"
                       x:DataType="x:String">
             <renderer:MarkdownTextBlock Background="Transparent"
+                                        LinkClicked="MarkdownTextBlock_LinkClicked"
                                         Text="{Binding}"
                                         TextWrapping="WrapWholeWords" />
         </DataTemplate>

common/CommunityToolkit.Labs.Shared/Renderers/ToolkitDocumentationRenderer.xaml.cs

@@ -5,6 +5,15 @@
 using CommunityToolkit.Labs.Core.SourceGenerators;
 using CommunityToolkit.Labs.Core.SourceGenerators.Metadata;
 using Windows.Storage;
+using Windows.System;
+
+#if !HAS_UNO
+#if !WINAPPSDK
+using Microsoft.Toolkit.Uwp.UI.Controls;
+#else
+using CommunityToolkit.WinUI.UI.Controls;
+#endif
+#endif
 
 namespace CommunityToolkit.Labs.Shared.Renderers;
 
@@ -113,8 +122,12 @@ private async Task LoadData()
                 index = match.Index + match.Length;
             }
 
-            // Put rest of text at end
-            DocsAndSamples.Add(doctext.Substring(index));
+            var rest = doctext.Substring(index).Trim();
+            // Put rest of text at end (if any)
+            if (rest.Length > 0)
+            {
+                DocsAndSamples.Add(rest);
+            }
         }
     }
 
@@ -174,4 +187,30 @@ private static async Task<string> GetDocumentationFileContents(ToolkitFrontMatte
             return $"Exception Encountered Loading file '{fileUri}':\n{e.Message}\n{e.StackTrace}";
         }
     }
+
+
+#if HAS_UNO
+    private void MarkdownTextBlock_LinkClicked(object sender, LinkClickedEventArgs e)
+    {
+        // No-op - TODO: See https://github.com/CommunityToolkit/Labs-Windows/issues/151
+    }
+#elif !HAS_UNO
+    private async void MarkdownTextBlock_LinkClicked(object sender, LinkClickedEventArgs e)
+    {
+        if (!Uri.IsWellFormedUriString(e.Link, UriKind.Absolute))
+        {
+            await new ContentDialog
+            {
+                Title = "Windows Community Toolkit Labs Sample App",
+                Content = $"Link {e.Link} was malformed.",
+                CloseButtonText = "Close",
+                XamlRoot = XamlRoot // TODO: For UWP this is only on 1903+
+            }.ShowAsync();
+        }
+        else
+        {
+            await Launcher.LaunchUriAsync(new Uri(e.Link));
+        }
+    }
+#endif
 }

template/lab/samples/ProjectTemplate.Samples/ProjectTemplate.md

@@ -18,6 +18,7 @@ subcategory: Layout
 # ProjectTemplate
 
 For more information about this experiment see:
+
 - Discussion: TODO: PASTE LINK HERE
 - Issue: TODO: PASTE LINK HERE