Update Web browser control for Markdown Previewer (microsoft#1464)

* Updated Webbrowser control * Updated Unit tests * Disabled Navigation for Svg Previewer
udit3333 · Mar 10, 2020 · efc711e · efc711e
1 parent bb0076e
commit efc711e
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Showing 4 changed files with 25 additions and 50 deletions.
diff --git a/src/modules/previewpane/MarkdownPreviewHandler/MarkdownPreviewHandlerControl.cs b/src/modules/previewpane/MarkdownPreviewHandler/MarkdownPreviewHandlerControl.cs
@@ -12,6 +12,7 @@
 using Common;
 using Markdig;
 using MarkdownPreviewHandler.Properties;
+using PreviewHandlerCommon;
 
 namespace MarkdownPreviewHandler
 {
@@ -46,9 +47,9 @@ public class MarkdownPreviewHandlerControl : FormHandlerControl
         private RichTextBox infoBar;
 
         /// <summary>
-        /// WebBrowser control to display markdown html.
+        /// Extended Browser Control to display markdown html.
         /// </summary>
-        private WebBrowser browser;
+        private WebBrowserExt browser;
 
         /// <summary>
         /// True if external image is blocked, false otherwise.
@@ -85,17 +86,17 @@ public override void DoPreview<T>(T dataSource)
                     MarkdownPipeline pipeline = this.pipelineBuilder.Build();
                     string parsedMarkdown = Markdown.ToHtml(fileText, pipeline);
                     sb.AppendFormat("{0}{1}{2}", this.htmlHeader, parsedMarkdown, this.htmlFooter);
-                    string markdownHTML = this.RemoveScriptFromHTML(sb.ToString());
+                    string markdownHTML = sb.ToString();
 
-                    this.browser = new WebBrowser
+                    this.browser = new WebBrowserExt
                     {
                         DocumentText = markdownHTML,
                         Dock = DockStyle.Fill,
                         IsWebBrowserContextMenuEnabled = false,
                         ScriptErrorsSuppressed = true,
                         ScrollBarsEnabled = true,
+                        AllowNavigation = false,
                     };
-                    this.browser.Navigating += this.WebBrowserNavigating;
                     this.Controls.Add(this.browser);
 
                     if (this.infoBarDisplayed)
@@ -121,23 +122,6 @@ public override void DoPreview<T>(T dataSource)
             });
         }
 
-        /// <summary>
-        /// Removes script tag from html string.
-        /// </summary>
-        /// <param name="html">html string.</param>
-        /// <returns>HTML string without script tag.</returns>
-        public string RemoveScriptFromHTML(string html)
-        {
-            HtmlAgilityPack.HtmlDocument doc = new HtmlAgilityPack.HtmlDocument();
-            doc.LoadHtml(html);
-
-            doc.DocumentNode.Descendants()
-                            .Where(n => n.Name == "script")
-                            .ToList()
-                            .ForEach(n => n.Remove());
-            return doc.DocumentNode.InnerHtml;
-        }
-
         /// <summary>
         /// Gets a textbox control.
         /// </summary>
@@ -191,16 +175,5 @@ private void ImagesBlockedCallBack()
         {
             this.infoBarDisplayed = true;
         }
-
-        /// <summary>
-        /// Callback when link tag is clicked in html.
-        /// </summary>
-        /// <param name="sender">Reference to resized control.</param>
-        /// <param name="e">Provides data for the WebBrowserNavigatingEventArgs event.</param>
-        private void WebBrowserNavigating(object sender, WebBrowserNavigatingEventArgs e)
-        {
-            e.Cancel = true;
-            Process.Start(e.Url.ToString());
-        }
     }
 }
diff --git a/src/modules/previewpane/PreviewPaneUnitTests/MarkdownPreviewHandlerTest.cs b/src/modules/previewpane/PreviewPaneUnitTests/MarkdownPreviewHandlerTest.cs
@@ -7,6 +7,7 @@
 using Markdig;
 using MarkdownPreviewHandler;
 using Microsoft.VisualStudio.TestTools.UnitTesting;
+using PreviewHandlerCommon;
 
 namespace PreviewPaneUnitTests
 {
@@ -24,7 +25,7 @@ public void MarkdownPreviewHandlerControl__AddsBrowserToForm_WhenDoPreviewIsCall
 
             // Assert
             Assert.AreEqual(markdownPreviewHandlerControl.Controls.Count, 2);
-            Assert.IsInstanceOfType(markdownPreviewHandlerControl.Controls[0], typeof(WebBrowser));
+            Assert.IsInstanceOfType(markdownPreviewHandlerControl.Controls[0], typeof(WebBrowserExt));
         }
 
         [TestMethod]
@@ -52,7 +53,7 @@ public void MarkdownPreviewHandlerControl__DoesNotAddInfoBarToFormIfExternalImag
 
             // Assert
             Assert.AreEqual(markdownPreviewHandlerControl.Controls.Count, 1);
-            Assert.IsInstanceOfType(markdownPreviewHandlerControl.Controls[0], typeof(WebBrowser));
+            Assert.IsInstanceOfType(markdownPreviewHandlerControl.Controls[0], typeof(WebBrowserExt));
         }
 
         [TestMethod]
@@ -65,12 +66,13 @@ public void MarkdownPreviewHandlerControl__UpdatesWebBrowserSettings_WhenDoPrevi
             markdownPreviewHandlerControl.DoPreview<string>("HelperFiles/MarkdownWithExternalImage.txt");
 
             // Assert
-            Assert.IsInstanceOfType(markdownPreviewHandlerControl.Controls[0], typeof(WebBrowser));
+            Assert.IsInstanceOfType(markdownPreviewHandlerControl.Controls[0], typeof(WebBrowserExt));
             Assert.IsNotNull(((WebBrowser)markdownPreviewHandlerControl.Controls[0]).DocumentText);
             Assert.AreEqual(((WebBrowser)markdownPreviewHandlerControl.Controls[0]).Dock, DockStyle.Fill);
             Assert.AreEqual(((WebBrowser)markdownPreviewHandlerControl.Controls[0]).IsWebBrowserContextMenuEnabled, false);
             Assert.AreEqual(((WebBrowser)markdownPreviewHandlerControl.Controls[0]).ScriptErrorsSuppressed, true);
             Assert.AreEqual(((WebBrowser)markdownPreviewHandlerControl.Controls[0]).ScrollBarsEnabled, true);
+            Assert.AreEqual(((WebBrowser)markdownPreviewHandlerControl.Controls[0]).AllowNavigation, false);
         }
 
         [TestMethod]
@@ -90,19 +92,5 @@ public void MarkdownPreviewHandlerControl__UpdateInfobarSettings_WhenDoPreviewIs
             Assert.AreEqual(((RichTextBox)markdownPreviewHandlerControl.Controls[1]).BackColor, Color.LightYellow);
             Assert.AreEqual(((RichTextBox)markdownPreviewHandlerControl.Controls[1]).Multiline, true);
         }
-
-        [TestMethod]
-        public void MarkdownPreviewHandlerControl_RemovesScriptTags_RemoveScriptFromHTMLIsCalled()
-        {
-            // Arrange
-            MarkdownPreviewHandlerControl markdownPreviewHandlerControl = new MarkdownPreviewHandlerControl();
-            string html = "<html><style></style><script>alert(\"hello\");</script><script></script></html>";
-
-            // Act
-            string parsedHTML = markdownPreviewHandlerControl.RemoveScriptFromHTML(html);
-
-            // Assert
-            Assert.AreEqual(parsedHTML, "<html>\r\n  <style></style>\r\n</html>");
-        }
     }
 }
diff --git a/src/modules/previewpane/SvgPreviewHandler/SvgPreviewControl.cs b/src/modules/previewpane/SvgPreviewHandler/SvgPreviewControl.cs
@@ -110,6 +110,7 @@ private void AddBrowserControl(string svgData)
             this.browser.IsWebBrowserContextMenuEnabled = false;
             this.browser.ScriptErrorsSuppressed = true;
             this.browser.ScrollBarsEnabled = true;
+            this.browser.AllowNavigation = false;
             this.Controls.Add(this.browser);
         }
 

diff --git a/src/modules/previewpane/UnitTests-SvgPreviewHandler/SvgPreviewControlTests.cs b/src/modules/previewpane/UnitTests-SvgPreviewHandler/SvgPreviewControlTests.cs
@@ -94,6 +94,19 @@ public void SvgPreviewControl_ShouldSetScrollBarsEnabledProperty_WhenDoPreviewCa
             Assert.AreEqual(((WebBrowser)svgPreviewControl.Controls[0]).ScrollBarsEnabled, true);
         }
 
+        [TestMethod]
+        public void SvgPreviewControl_ShouldDisableAllowNavigation_WhenDoPreviewCalled()
+        {
+            // Arrange
+            var svgPreviewControl = new SvgPreviewControl();
+
+            // Act
+            svgPreviewControl.DoPreview(GetMockStream("<svg></svg>"));
+
+            // Assert
+            Assert.AreEqual(((WebBrowser)svgPreviewControl.Controls[0]).AllowNavigation, false);
+        }
+
         [TestMethod]
         public void SvgPreviewControl_ShouldAddValidInfoBar_IfSvgPreviewThrows()
         {