HtmlNode.cs

using System.Collections.Generic;
using System.Text;
using System.Xml;

namespace Waher.Content.Html
{
	/// <summary>
	/// Base class for all HTML nodes.
	/// </summary>
	public abstract class HtmlNode
	{
		private readonly HtmlDocument document;
		private readonly HtmlNode parent;
		private int start;
		private int end;

		/// <summary>
		/// Base class for all HTML nodes.
		/// </summary>
		/// <param name="Document">HTML Document.</param>
		/// <param name="Parent">Parent node. Can be null for root elements.</param>
		/// <param name="StartPosition">Start position.</param>
		public HtmlNode(HtmlDocument Document, HtmlNode Parent, int StartPosition)
		{
			this.document = Document;
			this.parent = Parent;
			this.start = StartPosition;
			this.end = -1;
		}

		/// <summary>
		/// Base class for all HTML nodes.
		/// </summary>
		/// <param name="Document">HTML Document.</param>
		/// <param name="Parent">Parent node. Can be null for root elements.</param>
		/// <param name="StartPosition">Start position.</param>
		/// <param name="EndPosition">End position.</param>
		public HtmlNode(HtmlDocument Document, HtmlNode Parent, int StartPosition, int EndPosition)
		{
			this.document = Document;
			this.parent = Parent;
			this.start = StartPosition;
			this.end = EndPosition;
		}

		/// <summary>
		/// HTML Document
		/// </summary>
		public HtmlDocument Document => this.document;

		/// <summary>
		/// Parent node, if available.
		/// </summary>
		public HtmlNode Parent => this.parent;

		/// <summary>
		/// Start position of element.
		/// </summary>
		public int StartPosition
		{
			get => this.start;
			internal set => this.start = value;
		}

		/// <summary>
		/// End position of element.
		/// </summary>
		public int EndPosition
		{
			get => this.end;
			internal set => this.end = value;
		}

		/// <summary>
		/// Outer HTML
		/// </summary>
		public string OuterHtml
		{
			get
			{
				return this.document.HtmlText.Substring(this.start, this.end - this.start + 1);
			}
		}

		/// <summary>
		/// Splits a full name into a prefix (if available) and a local name.
		/// </summary>
		/// <param name="FullName">Full Name</param>
		/// <param name="Prefix">Prefix part</param>
		/// <param name="LocalName">Local name</param>
		/// <param name="HasPrefix">If a prefix was found.</param>
		protected static void SplitName(string FullName, out string Prefix, out string LocalName,
			out bool HasPrefix)
		{
			int i = FullName.IndexOf(':');
			if (i < 0)
			{
				LocalName = FullName;
				Prefix = null;
				HasPrefix = false;
			}
			else
			{
				Prefix = FullName.Substring(0, i);
				LocalName = FullName.Substring(i + 1);
				HasPrefix = true;
			}
		}

		/// <summary>
		/// Exports the HTML document to XML.
		/// </summary>
		/// <param name="Output">XML Output</param>
		/// <param name="Namespaces">Namespaces defined, by prefix.</param>
		public abstract void Export(XmlWriter Output, Dictionary<string, string> Namespaces);

		/// <summary>
		/// Exports the HTML document to XML.
		/// </summary>
		/// <param name="Output">XML Output</param>
		public abstract void Export(StringBuilder Output);
	}
}