Add XmlDocument methods

SharpHelpers/SharpHelpers/XmlDocumentHelper.cs

@@ -1,6 +1,7 @@
 // (c) 2019 SharpCoding
 // This code is licensed under MIT license (see LICENSE.txt for details)
 using System;
+using System.IO;
 using System.Text;
 using System.Xml;
 using System.Xml.Linq;
@@ -10,10 +11,11 @@ namespace SharpCoding.SharpHelpers
     public static class XmlDocumentHelper
     {
         /// <summary>
-        /// Return a XmlDocument from a XDocument
+        /// Converts an XDocument to an XmlDocument.
         /// </summary>
-        /// <param name="xDocument"></param>
-        /// <returns></returns>
+        /// <param name="xDocument">The XDocument to convert.</param>
+        /// <returns>The converted XmlDocument.</returns>
+        /// <exception cref="ArgumentNullException">Thrown when xDocument is null.</exception>
         public static XmlDocument ToXmlDocument(this XDocument xDocument)
         {
             if (xDocument == null) throw new ArgumentNullException(nameof(xDocument));
@@ -27,10 +29,11 @@ public static XmlDocument ToXmlDocument(this XDocument xDocument)
         }
 
         /// <summary>
-        /// Return a XDocument from a XmlDocument
+        /// Converts an XmlDocument to an XDocument.
         /// </summary>
-        /// <param name="xmlDocument"></param>
-        /// <returns></returns>
+        /// <param name="xmlDocument">The XmlDocument to convert.</param>
+        /// <returns>The converted XDocument.</returns>
+        /// <exception cref="ArgumentNullException">Thrown when xmlDocument is null.</exception>
         public static XDocument ToXDocument(this XmlDocument xmlDocument)
         {
             if (xmlDocument == null) throw new ArgumentNullException(nameof(xmlDocument));
@@ -43,10 +46,11 @@ public static XDocument ToXDocument(this XmlDocument xmlDocument)
         }
 
         /// <summary>
-        /// Return a XmlDocument from a XElement
+        /// Converts an XElement to an XmlDocument.
         /// </summary>
-        /// <param name="xElement"></param>
-        /// <returns></returns>
+        /// <param name="xElement">The XElement to convert.</param>
+        /// <returns>The converted XmlDocument.</returns>
+        /// <exception cref="ArgumentNullException">Thrown when xElement is null.</exception>
         public static XmlDocument ToXmlDocument(this XElement xElement)
         {
             if (xElement == null) throw new ArgumentNullException(nameof(xElement));
@@ -61,5 +65,74 @@ public static XmlDocument ToXmlDocument(this XElement xElement)
             doc.LoadXml(sb.ToString());
             return doc;
         }
+
+        /// <summary>
+        /// Finds the first child node with the specified name.
+        /// </summary>
+        /// <param name="xmlDocument">The XmlDocument to search.</param>
+        /// <param name="nodeName">The name of the node to find.</param>
+        /// <returns>The first matching XmlNode, or null if not found.</returns>
+        public static XmlNode FindFirstChild(this XmlDocument xmlDocument, string nodeName)
+        {
+            if (xmlDocument == null) throw new ArgumentNullException(nameof(xmlDocument));
+            if (string.IsNullOrWhiteSpace(nodeName)) throw new ArgumentException("Node name cannot be null or empty.", nameof(nodeName));
+
+            return xmlDocument.SelectSingleNode($"//{nodeName}");
+        }
+
+        /// <summary>
+        /// Adds a new child element with the specified name and value to the given parent node.
+        /// </summary>
+        /// <param name="xmlDocument">The XmlDocument to modify.</param>
+        /// <param name="parentNode">The parent node to which the new element will be added.</param>
+        /// <param name="elementName">The name of the new element.</param>
+        /// <param name="elementValue">The value of the new element.</param>
+        /// <returns>The newly created XmlElement.</returns>
+        public static XmlElement AddChildElement(this XmlDocument xmlDocument, XmlNode parentNode, string elementName, string elementValue)
+        {
+            if (xmlDocument == null) throw new ArgumentNullException(nameof(xmlDocument));
+            if (parentNode == null) throw new ArgumentNullException(nameof(parentNode));
+            if (string.IsNullOrWhiteSpace(elementName)) throw new ArgumentException("Element name cannot be null or empty.", nameof(elementName));
+
+            var newElement = xmlDocument.CreateElement(elementName);
+            newElement.InnerText = elementValue;
+            parentNode.AppendChild(newElement);
+            return newElement;
+        }
+
+        /// <summary>
+        /// Converts the XmlDocument to a formatted string.
+        /// </summary>
+        /// <param name="xmlDocument">The XmlDocument to convert.</param>
+        /// <returns>A string representation of the XmlDocument.</returns>
+        public static string ToFormattedString(this XmlDocument xmlDocument)
+        {
+            if (xmlDocument == null) throw new ArgumentNullException(nameof(xmlDocument));
+
+            using (var stringWriter = new StringWriter())
+            {
+                using (var xmlWriter = XmlWriter.Create(stringWriter, new XmlWriterSettings { Indent = true }))
+                {
+                    xmlDocument.Save(xmlWriter);
+                }
+                return stringWriter.ToString();
+            }
+        }
+
+        /// <summary>
+        /// Removes the specified node from the XmlDocument.
+        /// </summary>
+        /// <param name="xmlDocument">The XmlDocument to modify.</param>
+        /// <param name="node">The node to remove.</param>
+        public static void RemoveNode(this XmlDocument xmlDocument, XmlNode node)
+        {
+            if (xmlDocument == null) throw new ArgumentNullException(nameof(xmlDocument));
+            if (node == null) throw new ArgumentNullException(nameof(node));
+
+            if (node.ParentNode != null)
+            {
+                node.ParentNode.RemoveChild(node);
+            }
+        }
     }
 }