node.cs

工作流的基本资料(文档资料

using System;
using System.Collections;
using System.Xml;
using System.Xml.XPath;

namespace com.use.wfp.util
{
	/// <summary>
	/// Node 的摘要说明。
	/// </summary>
	public interface Node{
		IList SelectNodes(String xPath);
		Node SelectSingleNode(String xPath);
		IList GetChildren();
		IDictionary GetAttributes();
		String GetName();
		String GetText();
		bool IsEmpty();
	}

	class EmptyNode:Node
	{
		public IList SelectNodes(String xPath)
		{
			return children;
		}

		public Node SelectSingleNode(String xPath)
		{
			return this;
		}

		public IList GetChildren()
		{
			return children;
		}

		public IDictionary GetAttributes()
		{
			return attrs;
		}

		public String GetName()
		{
			return "";
		}
		
		public String GetText()
		{
			return "";
		}

		public bool IsEmpty(){
			return true;
		}
		private IDictionary attrs = new Hashtable();
		private IList children = new ArrayList();
	}

	class NonEmptyNode:Node
	{
		private IDictionary attrs;
		private IList children;
		private String text;
		private XmlNode xml_node;

		public NonEmptyNode(XmlNode xmlNode)
		{
			this.xml_node = xmlNode;
		}
		public IList SelectNodes(String xPath)
		{
			return Convert( xml_node.SelectNodes(xPath) );
		}
		public Node SelectSingleNode(String xPath)
		{
			return NodeFactory.CreateNode(xml_node.SelectSingleNode(xPath));
		}
		public IList GetChildren()
		{
			if(children == null)
			{
				children = Convert(xml_node.ChildNodes);
			}
			return children;
		}
		public IDictionary GetAttributes()
		{
			if(attrs == null)
			{
				attrs = Convert(xml_node.Attributes);
			}
			return attrs;
		}
		public String GetName()
		{
			return xml_node.Name;;
		}		
		public String GetText()
		{
			if(text == null)
			{
				text = xml_node.InnerText + "";
			}
			return text;
		}
		public bool IsEmpty()
		{
			return false;
		}

		private IList Convert(XmlNodeList nodeList)
		{
			ArrayList retList = new ArrayList();
			foreach (XmlNode xmlNode in nodeList)
			{
				retList.Add(NodeFactory.CreateNode(xmlNode));
			}
			return retList;
		}
		private IDictionary Convert(XmlAttributeCollection xmlAttrs)
		{
			IDictionary attrs = new Hashtable();
			foreach (XmlNode xmlNode in xmlAttrs)
			{
				attrs.Add(xmlNode.Name, xmlNode.Value);
			}
			return attrs;
		}
	}
	public class NodeFactory
	{
		private NodeFactory(){}
		private static Node empty = new EmptyNode();

		public static Node CreateNode(String fileName){
			XmlDocument myXmlDocument = new XmlDocument();
			myXmlDocument.Load (fileName);
			return myXmlDocument.DocumentElement == null ? empty : new NonEmptyNode(myXmlDocument.DocumentElement);
		}
		public static Node CreateNode(XmlNode xmlNode){
			return xmlNode == null ? empty : new NonEmptyNode(xmlNode);
		}
		public static Node CreateEmptyNode()
		{
			return empty;
		}
	}
}