feat: Add Aspose.HTML .NET C# Examples — Html Navigation

html-navigation/add-aria-label-attributes-to-navigation-links-without-descriptive-text-screen-readers.cs

@@ -0,0 +1,75 @@
+// Add aria‑label attributes to navigation links lacking descriptive text for screen readers.
+
+using System;
+using System.IO;
+
+class Program
+{
+    static void Main(string[] args)
+    {
+        try
+        {
+            string html = "<!DOCTYPE html><html><head><title>Test</title></head><body><nav><ul><li><a href=\"home.html\"></a></li><li><a href=\"about.html\">About</a></li><li><a href=\"contact.html\"></a></li></ul></nav></body></html>";
+            string baseUri = "about:blank";
+
+            using (Aspose.Html.HTMLDocument document = new Aspose.Html.HTMLDocument(html, baseUri))
+            {
+                // Add aria-label to links without descriptive text
+                Aspose.Html.Collections.HTMLCollection anchors = document.GetElementsByTagName("a");
+                for (int i = 0; i < anchors.Length; i++)
+                {
+                    Aspose.Html.Dom.Element element = anchors[i] as Aspose.Html.Dom.Element;
+                    if (element != null)
+                    {
+                        Aspose.Html.HTMLAnchorElement anchor = element as Aspose.Html.HTMLAnchorElement;
+                        if (anchor != null)
+                        {
+                            string text = anchor.TextContent != null ? anchor.TextContent.Trim() : string.Empty;
+                            if (string.IsNullOrEmpty(text))
+                            {
+                                string href = anchor.GetAttribute("href");
+                                if (!string.IsNullOrEmpty(href))
+                                {
+                                    anchor.SetAttribute("aria-label", href);
+                                }
+                            }
+                        }
+                    }
+                }
+
+                // Validate accessibility
+                Aspose.Html.Accessibility.WebAccessibility webAccessibility = new Aspose.Html.Accessibility.WebAccessibility();
+                Aspose.Html.Accessibility.AccessibilityValidator validator = webAccessibility.CreateValidator(Aspose.Html.Accessibility.ValidationBuilder.All);
+                Aspose.Html.Accessibility.Results.ValidationResult validationResult = validator.Validate(document);
+                if (!validationResult.Success)
+                {
+                    foreach (Aspose.Html.Accessibility.Results.RuleValidationResult ruleResult in validationResult.Details)
+                    {
+                        if (!ruleResult.Success)
+                        {
+                            foreach (Aspose.Html.Accessibility.ITechniqueResult techResult in ruleResult.Errors)
+                            {
+                                if (techResult.Error.Target.TargetType == Aspose.Html.Accessibility.TargetTypes.HTMLElement)
+                                {
+                                    Aspose.Html.HTMLElement element = (Aspose.Html.HTMLElement)techResult.Error.Target.Item;
+                                    string tagName = element.TagName;
+                                    string attributeValue = element.GetAttribute("aria-label");
+                                    Console.WriteLine($"Tag: {tagName}, Attribute: {attributeValue}, Message: {techResult.Error.ErrorMessage}");
+                                }
+                            }
+                        }
+                    }
+                }
+
+                // Save modified HTML
+                string outputPath = Path.Combine(Directory.GetCurrentDirectory(), "output.html");
+                document.Save(outputPath);
+                Console.WriteLine($"Modified HTML saved to {outputPath}");
+            }
+        }
+        catch (Exception ex)
+        {
+            Console.WriteLine(ex.Message);
+        }
+    }
+}

html-navigation/add_crossorigin_attribute_to_external_script_tags_enable_cors_handling.cs → html-navigation/add-crossorigin-attribute-external-script-tags-enable-cors-handling.cs

@@ -1,16 +1,20 @@
 // Add a crossorigin attribute to external script tags to enable CORS handling.
 
+using System;
+
 class Program
 {
     static void Main()
     {
         try
         {
-            string htmlContent = "<html><head><script src=\"https://example.com/lib.js\"></script></head><body></body></html>";
+            string htmlContent = "<!DOCTYPE html><html><head><script src='https://example.com/lib.js'></script></head><body></body></html>";
             string tempFile = System.IO.Path.Combine(System.IO.Path.GetTempPath(), "sample.html");
             System.IO.File.WriteAllText(tempFile, htmlContent);
+
             Aspose.Html.Configuration configuration = new Aspose.Html.Configuration();
             configuration.Security |= Aspose.Html.Sandbox.Scripts;
+
             using (Aspose.Html.HTMLDocument document = new Aspose.Html.HTMLDocument(tempFile, configuration))
             {
                 Aspose.Html.Collections.HTMLCollection scriptElements = document.GetElementsByTagName("script");
@@ -23,13 +27,14 @@ static void Main()
                         scriptElement.SetAttribute("crossorigin", "anonymous");
                     }
                 }
+
                 string output = document.DocumentElement != null ? document.DocumentElement.OuterHTML : string.Empty;
                 System.Console.WriteLine(output);
             }
         }
         catch (System.Exception ex)
         {
-            System.Console.WriteLine("Error: " + ex.Message);
+            System.Console.Error.WriteLine("Error: " + ex.Message);
         }
     }
 }

html-navigation/add-custom-data-attribute-heading-elements-javascript-interaction.cs

@@ -0,0 +1,32 @@
+// Add a custom data‑attribute to all heading elements for JavaScript interaction later.
+
+using System;
+
+class Program
+{
+    static void Main()
+    {
+        try
+        {
+            var document = new Aspose.Html.HTMLDocument();
+            var body = document.Body;
+
+            var h1 = (Aspose.Html.HTMLHeadingElement)document.CreateElement("h1");
+            h1.SetAttribute("data-custom", "heading1");
+            h1.AppendChild(document.CreateTextNode("Heading 1"));
+            body.AppendChild(h1);
+
+            var h2 = (Aspose.Html.HTMLHeadingElement)document.CreateElement("h2");
+            h2.SetAttribute("data-custom", "heading2");
+            h2.AppendChild(document.CreateTextNode("Heading 2"));
+            body.AppendChild(h2);
+
+            string outputPath = "output.html";
+            document.Save(outputPath);
+        }
+        catch (System.Exception ex)
+        {
+            System.Console.WriteLine(ex.Message);
+        }
+    }
+}

html-navigation/add-custom-data-tracking-attribute-to-outbound-links-for-analytics.cs

@@ -0,0 +1,50 @@
+// Add a custom data‑tracking attribute to all outbound links for analytics purposes.
+
+using System;
+
+class Program
+{
+    static void Main(string[] args)
+    {
+        try
+        {
+            // Sample HTML content
+            string htmlContent = "<html><body>" +
+                                 "<a href=\"https://example.com\">External Link</a>" +
+                                 "<a href=\"/local\">Local Link</a>" +
+                                 "</body></html>";
+
+            // Load the document from the HTML string
+            using (Aspose.Html.HTMLDocument document = new Aspose.Html.HTMLDocument(htmlContent, "about:blank"))
+            {
+                // Select all anchor elements with href attribute
+                Aspose.Html.Collections.NodeList anchors = document.QuerySelectorAll("a[href]");
+
+                foreach (Aspose.Html.Dom.Node node in anchors)
+                {
+                    Aspose.Html.HTMLElement element = node as Aspose.Html.HTMLElement;
+                    if (element != null)
+                    {
+                        string href = element.GetAttribute("href");
+                        if (!string.IsNullOrEmpty(href) &&
+                            (href.StartsWith("http://", StringComparison.OrdinalIgnoreCase) ||
+                             href.StartsWith("https://", StringComparison.OrdinalIgnoreCase)))
+                        {
+                            // Add custom data-tracking attribute
+                            element.SetAttribute("data-tracking", Guid.NewGuid().ToString());
+                        }
+                    }
+                }
+
+                // Save the modified HTML to a file
+                string outputPath = "output.html";
+                document.Save(outputPath);
+                Console.WriteLine($"Modified HTML saved to: {outputPath}");
+            }
+        }
+        catch (Exception ex)
+        {
+            Console.WriteLine($"Error: {ex.Message}");
+        }
+    }
+}

html-navigation/add-language-attribute-html-tag-based-on-detected-content-language.cs

@@ -0,0 +1,28 @@
+// Add a language attribute to the html tag based on detected content language.
+
+class Program
+{
+    static void Main()
+    {
+        try
+        {
+            string htmlContent = "<!DOCTYPE html><html><head><title>Sample</title></head><body>Hello world!</body></html>";
+            // Simple language detection based on content
+            string languageCode = htmlContent.Contains("Bonjour") ? "fr" : "en";
+
+            Aspose.Html.HTMLDocument document = new Aspose.Html.HTMLDocument(htmlContent, "about:blank");
+
+            Aspose.Html.HTMLElement htmlElement = (Aspose.Html.HTMLElement)document.DocumentElement;
+            htmlElement.SetAttribute("lang", languageCode);
+
+            string outputPath = "output.html";
+            document.Save(outputPath);
+
+            System.Console.WriteLine("HTML saved to " + outputPath + " with lang='" + languageCode + "'.");
+        }
+        catch (System.Exception ex)
+        {
+            System.Console.WriteLine(ex.Message);
+        }
+    }
+}

html-navigation/add_missing_alt_attributes_to_img_tags_using_placeholder_description_for_accessibility.cs → html-navigation/add-missing-alt-attributes-img-tags-using-placeholder-description-accessibility.cs

@@ -1,35 +1,16 @@
 // Add missing alt attributes to img tags using a placeholder description for accessibility.
 
 using System;
-using System.IO;
-using System.Text;
 
 class Program
 {
     static void Main()
     {
         try
         {
-            // Prepare sample HTML content
-            string htmlContent = "<html><body>" +
-                                 "<img src='image1.png'>" +
-                                 "<img src='image2.png' alt='Existing alt'>" +
-                                 "</body></html>";
-
-            // Define input and output file paths
-            string inputPath = "sample.html";
-            string outputPath = "output.html";
-
-            // Write the sample HTML to a file
-            File.WriteAllText(inputPath, htmlContent, Encoding.UTF8);
-
-            // Load the HTML document
-            Aspose.Html.HTMLDocument document = new Aspose.Html.HTMLDocument(inputPath);
-
-            // Get all <img> elements
+            string htmlContent = "<!DOCTYPE html><html><head><title>Sample</title></head><body><img src='image1.png'><p>Text</p><img src='image2.jpg' alt='Existing alt'></body></html>";
+            Aspose.Html.HTMLDocument document = new Aspose.Html.HTMLDocument(htmlContent, "about:blank");
             Aspose.Html.Collections.HTMLCollection images = document.GetElementsByTagName("img");
-
-            // Iterate over each image element
             foreach (Aspose.Html.Dom.Element node in images)
             {
                 Aspose.Html.HTMLImageElement img = node as Aspose.Html.HTMLImageElement;
@@ -43,9 +24,7 @@ static void Main()
                     }
                 }
             }
-
-            // Save the modified document
-            document.Save(outputPath);
+            document.Save("output.html");
         }
         catch (Exception ex)
         {

html-navigation/add-missing-charset-meta-tag-detected-file-encoding-improve-compatibility.cs

@@ -0,0 +1,58 @@
+// Add a missing charset meta tag based on detected file encoding to improve compatibility.
+
+using System;
+using System.IO;
+using System.Text;
+
+class Program
+{
+    static void Main()
+    {
+        try
+        {
+            // Define input and output paths
+            string sourcePath = "input.html";
+            string outputPath = "output.html";
+
+            // Create a minimal sample HTML file if it does not exist
+            if (!File.Exists(sourcePath))
+            {
+                string sampleHtml = "<!DOCTYPE html><html><head><title>Sample</title></head><body><p>Hello World</p></body></html>";
+                File.WriteAllText(sourcePath, sampleHtml, Encoding.UTF8);
+            }
+
+            // Detect encoding (for this example we assume UTF-8)
+            string encodingName = "utf-8";
+            string htmlContent = File.ReadAllText(sourcePath, Encoding.GetEncoding(encodingName));
+
+            // Add charset meta tag if missing
+            if (!htmlContent.Contains("<meta charset=", StringComparison.OrdinalIgnoreCase))
+            {
+                if (htmlContent.Contains("<head>", StringComparison.OrdinalIgnoreCase))
+                {
+                    htmlContent = htmlContent.Replace("<head>", "<head><meta charset=\"utf-8\">", StringComparison.OrdinalIgnoreCase);
+                }
+                else if (htmlContent.Contains("<html>", StringComparison.OrdinalIgnoreCase))
+                {
+                    htmlContent = htmlContent.Replace("<html>", "<html><head><meta charset=\"utf-8\"></head>", StringComparison.OrdinalIgnoreCase);
+                }
+                else
+                {
+                    htmlContent = "<meta charset=\"utf-8\">" + htmlContent;
+                }
+            }
+
+            // Load HTML content into Aspose.HTML document
+            Aspose.Html.HTMLDocument document = new Aspose.Html.HTMLDocument(htmlContent, "about:blank");
+
+            // Save the modified document
+            document.Save(outputPath);
+
+            Console.WriteLine($"HTML saved to: {outputPath}");
+        }
+        catch (Exception ex)
+        {
+            Console.WriteLine($"Error: {ex.Message}");
+        }
+    }
+}

html-navigation/add_missing_doctype_declaration_at_beginning_of_html_file_to_ensure_standards_mode.cs → html-navigation/add-missing-doctype-declaration-beginning-html-file-ensure-standards-mode.cs

@@ -2,7 +2,7 @@
 
 using System;
 using System.IO;
-using Aspose.Html;
+using System.Text;
 
 class Program
 {
@@ -13,33 +13,31 @@ static void Main()
             string inputPath = "input.html";
             string outputPath = "output.html";
 
-            // Create a minimal sample HTML file without DOCTYPE if it doesn't exist
+            // Create a minimal sample HTML file if it does not exist
             if (!File.Exists(inputPath))
             {
                 string sampleHtml = "<html><head><title>Sample</title></head><body><p>Hello, World!</p></body></html>";
-                File.WriteAllText(inputPath, sampleHtml);
+                File.WriteAllText(inputPath, sampleHtml, Encoding.UTF8);
             }
 
-            // Load the HTML document using Aspose.Html
-            Aspose.Html.HTMLDocument document = new Aspose.Html.HTMLDocument(inputPath);
-
-            // Get the outer HTML of the document
-            string html = document.DocumentElement.OuterHTML;
+            // Read the HTML content
+            string html = File.ReadAllText(inputPath, Encoding.UTF8);
 
             // Add DOCTYPE if missing
             if (!html.TrimStart().StartsWith("<!DOCTYPE", StringComparison.OrdinalIgnoreCase))
             {
                 html = "<!DOCTYPE html>\n" + html;
             }
 
-            // Save the modified HTML to the output file
-            File.WriteAllText(outputPath, html);
+            // Load the HTML into Aspose.HTML document
+            Aspose.Html.HTMLDocument document = new Aspose.Html.HTMLDocument(html, "about:blank");
 
-            Console.WriteLine("HTML file processed successfully. Output saved to: " + outputPath);
+            // Save the updated document
+            document.Save(outputPath);
         }
         catch (Exception ex)
         {
-            Console.WriteLine("Error: " + ex.Message);
+            Console.WriteLine(ex.Message);
         }
     }
 }