XmlHierarchyData.cs source code in C# .NET

Source code for the .NET framework in C#

                        
Code:

                         / DotNET / DotNET / 8.0 / untmp / whidbey / REDBITS / ndp / fx / src / xsp / System / Web / UI / WebControls / XmlHierarchyData.cs / 2 / XmlHierarchyData.cs
                        

                        
                            //------------------------------------------------------------------------------ 
// 
//     Copyright (c) Microsoft Corporation.  All rights reserved.
// 
//----------------------------------------------------------------------------- 

namespace System.Web.UI.WebControls { 
 
    using System;
    using System.Collections; 
    using System.ComponentModel;
    using System.Data;
    using System.Drawing.Design;
    using System.Globalization; 
    using System.Text;
    using System.Web; 
    using System.Web.UI; 
    using System.Xml;
 
    using AttributeCollection = System.ComponentModel.AttributeCollection;


    ///  
    /// Represents the data associated with a single hierarchy item - in this case an XmlNode.
    ///  
    internal sealed class XmlHierarchyData : IHierarchyData, ICustomTypeDescriptor { 

        private XmlNode _item; 
        private XmlHierarchicalEnumerable _parent;
        private string _path;

        ///  
        /// Create a new instance of XmlHierarchyData.
        ///  
        internal XmlHierarchyData(XmlHierarchicalEnumerable parent, XmlNode item) { 
            _parent = parent;
            _item = item; 
        }


        ///  
        /// Creates a path to a given XmlNode from the root using XPath.
        ///  
        private string CreateRecursivePath(XmlNode node) { 
            if (node.ParentNode == null)
                return String.Empty; 

            return CreateRecursivePath(node.ParentNode) + FindNodePosition(node);
        }
 
        /// 
        /// Finds a node's position relative to its parent. 
        ///  
        private string FindNodePosition(XmlNode node) {
            XmlNodeList nodeList = node.ParentNode.ChildNodes; 

            int index = 0;

            for (int i = 0; i < nodeList.Count; i++) { 
                // Position only considers elements, not other node types
                if (nodeList[i].NodeType == XmlNodeType.Element) 
                    index++; 

                if (nodeList[i] == node) 
                    return "/*[position()=" + Convert.ToString(index, CultureInfo.InvariantCulture) + "]";
            }

            throw new ArgumentException(SR.GetString(SR.XmlHierarchyData_CouldNotFindNode)); 
        }
 
        public override string ToString() { 
            return _item.Name;
        } 


        bool IHierarchyData.HasChildren {
            get { 
                return _item.HasChildNodes;
            } 
        } 

        object IHierarchyData.Item { 
            get {
                return _item;
            }
        } 

        string IHierarchyData.Path { 
            get { 
                if (_path == null) {
                    // If we don't yet have a path, create one and cache it 
                    if (_parent != null) {
                        // If we have a parent enumerable, then our path is the parent's
                        // path plus our position within that parent.
                        if (_parent.Path == null) { 
                            _parent.Path = CreateRecursivePath(_item.ParentNode);
                        } 
                        _path = _parent.Path + FindNodePosition(_item); 
                    }
                    else { 
                        // If we are not associated with a parent enumerable, we
                        // have to build up our entire path from scratch.
                        _path = CreateRecursivePath(_item);
                    } 
                }
                return _path; 
            } 
        }
 
        string IHierarchyData.Type {
            get {
                return _item.Name;
            } 
        }
 
        IHierarchicalEnumerable IHierarchyData.GetChildren() { 
            return new XmlHierarchicalEnumerable(_item.ChildNodes);
        } 

        IHierarchyData IHierarchyData.GetParent() {
            XmlNode parentNode = _item.ParentNode;
            if (parentNode == null) 
                return null;
 
            return new XmlHierarchyData(null, parentNode); 
        }
 
        AttributeCollection ICustomTypeDescriptor.GetAttributes() {
            return AttributeCollection.Empty;
        }
 
        string ICustomTypeDescriptor.GetClassName() {
            return GetType().Name; 
        } 

        string ICustomTypeDescriptor.GetComponentName() { 
            return null;

        }
 
        TypeConverter ICustomTypeDescriptor.GetConverter() {
            return null; 
        } 

        EventDescriptor ICustomTypeDescriptor.GetDefaultEvent() { 
            return null;
        }

        PropertyDescriptor ICustomTypeDescriptor.GetDefaultProperty() { 
            return new XmlHierarchyDataPropertyDescriptor("#Name");
        } 
 
        object ICustomTypeDescriptor.GetEditor(Type editorBaseType) {
            return null; 
        }

        EventDescriptorCollection ICustomTypeDescriptor.GetEvents() {
            return null; 
        }
 
        EventDescriptorCollection ICustomTypeDescriptor.GetEvents(Attribute[] attrs) { 
            return null;
        } 

        PropertyDescriptorCollection ICustomTypeDescriptor.GetProperties() {
            return ((ICustomTypeDescriptor)this).GetProperties(null);
        } 

        PropertyDescriptorCollection ICustomTypeDescriptor.GetProperties(Attribute[] attrFilter) { 
            System.Collections.Generic.List list = new System.Collections.Generic.List(); 
            list.Add(new XmlHierarchyDataPropertyDescriptor("#Name"));
            list.Add(new XmlHierarchyDataPropertyDescriptor("#Value")); 
            list.Add(new XmlHierarchyDataPropertyDescriptor("#InnerText"));

            XmlAttributeCollection attrs = _item.Attributes;
            if (attrs != null) { 
                for (int i = 0; i < attrs.Count; i++) {
                    list.Add(new XmlHierarchyDataPropertyDescriptor(attrs[i].Name)); 
                } 
            }
 
            return new PropertyDescriptorCollection(list.ToArray());
        }

        object ICustomTypeDescriptor.GetPropertyOwner(PropertyDescriptor pd) { 
            if (pd is XmlHierarchyDataPropertyDescriptor) {
                return this; 
            } 

            return null; 
        }

        private class XmlHierarchyDataPropertyDescriptor : PropertyDescriptor {
            private string _name; 

            public XmlHierarchyDataPropertyDescriptor(string name) : base(name, null) { 
                _name = name; 
            }
 

            public override Type ComponentType {
                get {
                    return typeof(XmlHierarchyData); 
                }
            } 
 
            public override bool IsReadOnly {
                get { 
                    return true;
                }
            }
 
            public override Type PropertyType {
                get { 
                    return typeof(string); 
                }
            } 

            public override bool CanResetValue(object o) {
                return false;
            } 

            public override object GetValue(object o) { 
                XmlHierarchyData data = o as XmlHierarchyData; 
                if (data != null) {
                    switch (_name) { 
                        case "#Name":
                            return data._item.Name;
                        case "#Value":
                            return data._item.Value; 
                        case "#InnerText":
                            return data._item.InnerText; 
                        default: 
                            XmlAttributeCollection attrs = data._item.Attributes;
 
                            if (attrs != null) {
                                XmlAttribute attr = attrs[_name];
                                if (attr != null) {
                                    return attr.Value; 
                                }
                            } 
                            break; 
                    }
                } 

                return String.Empty;
            }
 
            public override void ResetValue(object o) {
                return; 
            } 

            public override void SetValue(object o, object value) { 
            }

            public override bool ShouldSerializeValue(object o) {
                return true; 
            }
        } 
    } 
}

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