SP-2372: Hooked up SILAboutBox to call HtmlUtils.CreatePatchedTempHtmlFile

Documented previously undocumented feature: SILAboutBox constructor can accept either a filename or a file URI.

Author: tombogle

CHANGELOG.md

@@ -36,7 +36,7 @@ and this project adheres to [Semantic Versioning](http://semver.org/).
 
 - [SIL.WritingSystems] Updated embedded langtags.json
 - [SIL.WritingSystems] Updated embedded ianaSubtagRegistry.txt
-
+- [SIL.Windows.Forms] Documented previously undocumented feature: SILAboutBox constructor can accept either a filename or a file URI.
 
 ## [16.0.0] - 2025-05-20
 

SIL.Windows.Forms/Miscellaneous/SILAboutBox.cs

@@ -87,7 +87,7 @@ public event WebBrowserNavigatedEventHandler Navigated
 		/// </summary>
 		/// <param name="pathToAboutBoxHtml">For example, use
 		/// <see cref="FileLocationUtilities.GetFileDistributedWithApplication(string[])"/>(
-		/// "DistFiles", "AboutBox.htm")</param>
+		/// "DistFiles", "AboutBox.htm"). This also can accept a file URI.</param>
 		/// <param name="useFullVersionNumber"><c>false</c> to display only the first three
 		/// parts of the version number, i.e. "MajorVersion.MinorVersion.Build",
 		/// <c>true</c> to display the full version number as found in Application.ProductVersion.
@@ -99,7 +99,10 @@ public SILAboutBox(string pathToAboutBoxHtml, bool useFullVersionNumber = false,
 			SilLogoVariant logoVariant = SilLogoVariant.Random)
 		{
 			_assembly = Assembly.GetEntryAssembly(); // assembly;
-			_pathToAboutBoxHtml = pathToAboutBoxHtml;
+			_pathToAboutBoxHtml =
+				Uri.TryCreate(pathToAboutBoxHtml, UriKind.Absolute, out var uri) && uri.IsFile
+					? uri.LocalPath
+					: pathToAboutBoxHtml;
 			InitializeComponent();
 			_versionNumber.Text = useFullVersionNumber ? Application.ProductVersion :
 				GetShortVersionInfo();
@@ -282,28 +285,7 @@ private void SILAboutBoxShown(object sender, EventArgs e)
 				_browser.Navigate(_pathToAboutBoxHtml);
 			else
 			{
-				// Note: the following comment also applies to the case where HandleMissingLinkTargets tweaks
-				// the HTML, but hopefully that will be rare in production code.
-				// Create a temporary file with the DependencyMarker replaced with our collected Acknowledgements.
-				// This file will be deleted OnClosed.
-				// This means that if your project uses the DependencyMarker in your html file, you will not be able to
-				// link to a file on a relative path for css styles or images.
-				// ----------
-				// Comments on possible ways around this limitation from John Thomson:
-				//		1.Document that an About Box HTML file which uses dependency injection must live in its own folder
-				// with all dependent files, and copy the whole folder to a temp folder.
-				// (could work but is a nuisance, especially for anyone who doesn't need any dependencies)
-				//		2.Document that an About Box HTML file which uses dependency injection may only use a few common kinds
-				// of relative links, search for matching links, and copy the appropriate files to a temp directory along
-				// with the temp file.
-				// (I rather like this idea. A fairly simple regular expression will search for src or rel followed by a value
-				// with no path separators...something like(src | rel) = (['"])([^/\]*)\1 (or something similar...
-				// handle white space...). That will catch all references to images, stylesheets, and scripts,
-				// and if the bit of the RegEx that matches the filename corresponds to an existing file in the same folder
-				// as the HTML we can just copy it. Unless they're doing relative paths to different folders that will do it,
-				// and I think it's reasonable to have SOME restrictions in the interests of simplicity.
-				// ----------
-				_tempAboutBoxHtmlFile = new TempFile(newHtmlContents);
+				_tempAboutBoxHtmlFile = HtmlUtils.CreatePatchedTempHtmlFile(newHtmlContents, _pathToAboutBoxHtml);
 				_browser.Navigate(_tempAboutBoxHtmlFile.Path);
 			}
 		}

TestApps/SIL.Windows.Forms.TestApp/TestAppForm.cs

@@ -171,10 +171,16 @@ private void ShowSilAboutBox(XWebBrowser.BrowserType browserType, bool useFullVe
 			string html;
 			var handleNavigation = false;
 			var allowExtLinksInsideAbout = false;
+			var createCss = false;
 			switch (_cboAboutHTML.SelectedIndex)
 			{
 				default: // Links without target attribute
-					html = @"<html><head><meta charset='UTF-8' /></head>
+					createCss = true;
+					html = @"<html>
+						<head>
+							<meta charset='UTF-8' />
+							<link rel=""stylesheet"" type=""text/css"" href=""aboutBox.css"" />
+						</head>
 						<body>
 						  <h3>Copyright 2025 <a href=""http://sil.org"">SIL Global</a></h3>
 						  <p>Testing the <b>about box</b></p>
@@ -214,10 +220,33 @@ private void ShowSilAboutBox(XWebBrowser.BrowserType browserType, bool useFullVe
 					allowExtLinksInsideAbout = true;
 					goto default;
 			}
-			using (var tempFile = TempFile.WithExtension("html"))
+
+			using var tempFile = TempFile.WithExtension("html");
+			File.WriteAllText(tempFile.Path, html);
+
+			TempFile cssFile = null;
+			if (createCss)
+			{
+				cssFile = TempFile.WithFilename("aboutBox.css");
+				File.WriteAllText(cssFile.Path, @"
+						body {
+							font-family: sans-serif;
+						}
+						a {
+							color: orange;
+							text-decoration: underline;
+						}
+						a:visited {
+							color: green;
+						}
+						a:hover {
+							text-decoration: none;
+						}
+					");
+			}
+
+			try
 			{
-				File.WriteAllText(tempFile.Path, html);
-					
 				var uri = new Uri(tempFile.Path);
 				using (var dlg = new SILAboutBox(uri.AbsoluteUri, useFullVersionNumber))
 				{
@@ -230,16 +259,25 @@ private void ShowSilAboutBox(XWebBrowser.BrowserType browserType, bool useFullVe
 								firstNav = false;
 								return;
 							}
+
 							args.Cancel = DialogResult.Cancel == MessageBox.Show(
-								string.Format(LocalizationManager.GetString("About.ExternalNavigationConfirmationMsg",
-								"Request to navigate to {0} with target frame {1}"), args.Url, args.TargetFrameName),
-								LocalizationManager.GetString("About.ExternalNavigationConfirmationTitle",
+								string.Format(LocalizationManager.GetString(
+										"About.ExternalNavigationConfirmationMsg",
+										"Request to navigate to {0} with target frame {1}"),
+									args.Url,
+									args.TargetFrameName),
+								LocalizationManager.GetString(
+									"About.ExternalNavigationConfirmationTitle",
 									"External navigation request"), MessageBoxButtons.OKCancel);
 						};
 					dlg.AllowExternalLinksToOpenInsideAboutBox = allowExtLinksInsideAbout;
 					dlg.ShowDialog();
 				}
 			}
+			finally
+			{
+				cssFile?.Dispose();
+			}
 		}
 
 		private void OnShowReleaseNotesClicked(object sender, EventArgs e)