XmlNavigatorFilter.cs source code in C# .NET

                        Code:
                         / 4.0 / 4.0 / untmp / DEVDIV_TFS / Dev10 / Releases / RTMRel / ndp / fx / src / XmlUtils / System / Xml / Xsl / Runtime / XmlNavigatorFilter.cs / 1305376 / XmlNavigatorFilter.cs
                        
                        
                            //------------------------------------------------------------------------------ 
// 
//     Copyright (c) Microsoft Corporation.  All rights reserved.
// 
// [....] 
//-----------------------------------------------------------------------------
using System.Xml; 
using System.Xml.XPath; 
using System.Diagnostics;
using System.ComponentModel; 

namespace System.Xml.Xsl.Runtime {

    ///  
    /// XmlNavigatorFilter provides a flexible filtering abstraction over XPathNavigator.  Callers do
    /// not know what type of filtering will occur; they simply call MoveToContent or MoveToSibling. 
    /// The filter implementation invokes appropriate operation(s) on the XPathNavigator in order 
    /// to skip over filtered nodes.
    ///  
    [EditorBrowsable(EditorBrowsableState.Never)]
    public abstract class XmlNavigatorFilter {
        /// 
        /// Reposition the navigator to the first matching content node (inc. attributes); skip over 
        /// filtered nodes.  If there are no matching nodes, then don't move navigator and return false.
        ///  
        public abstract bool MoveToContent(XPathNavigator navigator); 

        ///  
        /// Reposition the navigator to the next matching content node (inc. attributes); skip over
        /// filtered nodes.  If there are no matching nodes, then don't move navigator and return false.
        /// 
        public abstract bool MoveToNextContent(XPathNavigator navigator); 

        ///  
        /// Reposition the navigator to the next following sibling node (no attributes); skip over 
        /// filtered nodes.  If there are no matching nodes, then don't move navigator and return false.
        ///  
        public abstract bool MoveToFollowingSibling(XPathNavigator navigator);

        /// 
        /// Reposition the navigator to the previous sibling node (no attributes); skip over filtered 
        /// nodes.  If there are no matching nodes, then don't move navigator and return false.
        ///  
        public abstract bool MoveToPreviousSibling(XPathNavigator navigator); 

        ///  
        /// Reposition the navigator to the next following node (inc. descendants); skip over filtered nodes.
        /// If there are no matching nodes, then return false.
        /// 
        public abstract bool MoveToFollowing(XPathNavigator navigator, XPathNavigator navigatorEnd); 

        ///  
        /// Return true if the navigator's current node matches the filter condition. 
        /// 
        public abstract bool IsFiltered(XPathNavigator navigator); 
    }


    ///  
    /// Filters any non-element and any element with a non-matching local name or namespace uri.
    ///  
    internal class XmlNavNameFilter : XmlNavigatorFilter { 
        private string localName;
        private string namespaceUri; 

        /// 
        /// Return an XmlNavigatorFilter that skips over nodes that do not match the specified name.
        ///  
        public static XmlNavigatorFilter Create(string localName, string namespaceUri) {
            return new XmlNavNameFilter(localName, namespaceUri); 
        } 

        ///  
        /// Keep only elements with name = localName, namespaceUri.
        /// 
        private XmlNavNameFilter(string localName, string namespaceUri) {
            this.localName = localName; 
            this.namespaceUri = namespaceUri;
        } 
 
        /// 
        /// Reposition the navigator on the first element child with a matching name. 
        /// 
        public override bool MoveToContent(XPathNavigator navigator) {
            return navigator.MoveToChild(this.localName, this.namespaceUri);
        } 

        ///  
        /// Reposition the navigator on the next element child with a matching name. 
        /// 
        public override bool MoveToNextContent(XPathNavigator navigator) { 
            return navigator.MoveToNext(this.localName, this.namespaceUri);
        }

        ///  
        /// Reposition the navigator on the next element sibling with a matching name.
        ///  
        public override bool MoveToFollowingSibling(XPathNavigator navigator) { 
            return navigator.MoveToNext(this.localName, this.namespaceUri);
        } 

        /// 
        /// Reposition the navigator on the previous element sibling with a matching name.
        ///  
        public override bool MoveToPreviousSibling(XPathNavigator navigator) {
            return navigator.MoveToPrevious(this.localName, this.namespaceUri); 
        } 

        ///  
        /// Reposition the navigator on the next following element with a matching name.
        /// 
        public override bool MoveToFollowing(XPathNavigator navigator, XPathNavigator navEnd) {
            return navigator.MoveToFollowing(this.localName, this.namespaceUri, navEnd); 
        }
 
        ///  
        /// Return false if the navigator is positioned on an element with a matching name.
        ///  
        public override bool IsFiltered(XPathNavigator navigator) {
            return navigator.LocalName != this.localName || navigator.NamespaceURI != namespaceUri;
        }
    } 

 
    ///  
    /// Filters any node not of the specified type (type may not be attribute or namespace).
    ///  
    internal class XmlNavTypeFilter : XmlNavigatorFilter {
        private static XmlNavigatorFilter[] TypeFilters;
        private XPathNodeType nodeType;
        private int mask; 

        ///  
        /// There are a limited number of types, so create all possible XmlNavTypeFilter objects just once. 
        /// 
        static XmlNavTypeFilter() { 
            TypeFilters = new XmlNavigatorFilter[(int) XPathNodeType.Comment + 1];
            TypeFilters[(int) XPathNodeType.Element] = new XmlNavTypeFilter(XPathNodeType.Element);
            TypeFilters[(int) XPathNodeType.Text] = new XmlNavTypeFilter(XPathNodeType.Text);
            TypeFilters[(int) XPathNodeType.ProcessingInstruction] = new XmlNavTypeFilter(XPathNodeType.ProcessingInstruction); 
            TypeFilters[(int) XPathNodeType.Comment] = new XmlNavTypeFilter(XPathNodeType.Comment);
        } 
 
        /// 
        /// Return a previously constructed XmlNavigatorFilter that skips over nodes that do not match the specified type. 
        /// 
        public static XmlNavigatorFilter Create(XPathNodeType nodeType) {
            Debug.Assert(TypeFilters[(int) nodeType] != null);
            return TypeFilters[(int) nodeType]; 
        }
 
        ///  
        /// Keep only nodes with XPathNodeType = nodeType, where XPathNodeType.Text selects whitespace as well.
        ///  
        private XmlNavTypeFilter(XPathNodeType nodeType) {
            Debug.Assert(nodeType != XPathNodeType.Attribute && nodeType != XPathNodeType.Namespace);
            this.nodeType = nodeType;
            this.mask = XPathNavigator.GetContentKindMask(nodeType); 
        }
 
        ///  
        /// Reposition the navigator on the first child with a matching type.
        ///  
        public override bool MoveToContent(XPathNavigator navigator) {
            return navigator.MoveToChild(this.nodeType);
        }
 
        /// 
        /// Reposition the navigator on the next child with a matching type. 
        ///  
        public override bool MoveToNextContent(XPathNavigator navigator) {
            return navigator.MoveToNext(this.nodeType); 
        }

        /// 
        /// Reposition the navigator on the next non-attribute sibling with a matching type. 
        /// 
        public override bool MoveToFollowingSibling(XPathNavigator navigator) { 
            return navigator.MoveToNext(this.nodeType); 
        }
 
        /// 
        /// Reposition the navigator on the previous non-attribute sibling with a matching type.
        /// 
        public override bool MoveToPreviousSibling(XPathNavigator navigator) { 
            return navigator.MoveToPrevious(this.nodeType);
        } 
 
        /// 
        /// Reposition the navigator on the next following element with a matching kind. 
        /// 
        public override bool MoveToFollowing(XPathNavigator navigator, XPathNavigator navEnd) {
            return navigator.MoveToFollowing(this.nodeType, navEnd);
        } 

        ///  
        /// Return false if the navigator is positioned on a node with a matching type. 
        /// 
        public override bool IsFiltered(XPathNavigator navigator) { 
            return ((1 << (int) navigator.NodeType) & this.mask) == 0;
        }
    }
 

    ///  
    /// Filters all attribute nodes. 
    /// 
    internal class XmlNavAttrFilter : XmlNavigatorFilter { 
        private static XmlNavigatorFilter Singleton = new XmlNavAttrFilter();

        /// 
        /// Return a singleton XmlNavigatorFilter that filters all attribute nodes. 
        /// 
        public static XmlNavigatorFilter Create() { 
            return Singleton; 
        }
 
        /// 
        /// Constructor.
        /// 
        private XmlNavAttrFilter() { 
        }
 
        ///  
        /// Reposition the navigator on the first non-attribute child.
        ///  
        public override bool MoveToContent(XPathNavigator navigator) {
            return navigator.MoveToFirstChild();
        }
 
        /// 
        /// Reposition the navigator on the next non-attribute sibling. 
        ///  
        public override bool MoveToNextContent(XPathNavigator navigator) {
            return navigator.MoveToNext(); 
        }

        /// 
        /// Reposition the navigator on the next non-attribute sibling. 
        /// 
        public override bool MoveToFollowingSibling(XPathNavigator navigator) { 
            return navigator.MoveToNext(); 
        }
 
        /// 
        /// Reposition the navigator on the previous non-attribute sibling.
        /// 
        public override bool MoveToPreviousSibling(XPathNavigator navigator) { 
            return navigator.MoveToPrevious();
        } 
 
        /// 
        /// Reposition the navigator on the next following non-attribute. 
        /// 
        public override bool MoveToFollowing(XPathNavigator navigator, XPathNavigator navEnd) {
            return navigator.MoveToFollowing(XPathNodeType.All, navEnd);
        } 

        ///  
        /// Return true if the navigator is positioned on an attribute. 
        /// 
        public override bool IsFiltered(XPathNavigator navigator) { 
            return navigator.NodeType == XPathNodeType.Attribute;
        }
    }
 

    ///  
    /// Never filter nodes. 
    /// 
    internal class XmlNavNeverFilter : XmlNavigatorFilter { 
        private static XmlNavigatorFilter Singleton = new XmlNavNeverFilter();

        /// 
        /// Return a singleton XmlNavigatorFilter that never filters any nodes. 
        /// 
        public static XmlNavigatorFilter Create() { 
            return Singleton; 
        }
 
        /// 
        /// Constructor.
        /// 
        private XmlNavNeverFilter() { 
        }
 
        ///  
        /// Reposition the navigator on the first child (attribute or non-attribute).
        ///  
        public override bool MoveToContent(XPathNavigator navigator) {
            return MoveToFirstAttributeContent(navigator);
        }
 
        /// 
        /// Reposition the navigator on the next child (attribute or non-attribute). 
        ///  
        public override bool MoveToNextContent(XPathNavigator navigator) {
            return MoveToNextAttributeContent(navigator); 
        }

        /// 
        /// Reposition the navigator on the next sibling (no attributes). 
        /// 
        public override bool MoveToFollowingSibling(XPathNavigator navigator) { 
            return navigator.MoveToNext(); 
        }
 
        /// 
        /// Reposition the navigator on the previous sibling (no attributes).
        /// 
        public override bool MoveToPreviousSibling(XPathNavigator navigator) { 
            return navigator.MoveToPrevious();
        } 
 
        /// 
        /// Reposition the navigator on the next following node. 
        /// 
        public override bool MoveToFollowing(XPathNavigator navigator, XPathNavigator navEnd) {
            return navigator.MoveToFollowing(XPathNodeType.All, navEnd);
        } 

        ///  
        /// Nodes are never filtered so always return false. 
        /// 
        public override bool IsFiltered(XPathNavigator navigator) { 
            return false;
        }

        ///  
        /// Move to navigator's first attribute node.  If no attribute's exist, move to the first content node.
        /// If no content nodes exist, return null.  Otherwise, return navigator. 
        ///  
        public static bool MoveToFirstAttributeContent(XPathNavigator navigator) {
            if (!navigator.MoveToFirstAttribute()) 
                return navigator.MoveToFirstChild();
            return true;
        }
 
        /// 
        /// If navigator is positioned on an attribute, move to the next attribute node.  If there are no more 
        /// attributes, move to the first content node.  If navigator is positioned on a content node, move to 
        /// the next content node.  If there are no more attributes and content nodes, return null.
        /// Otherwise, return navigator. 
        /// 
        public static bool MoveToNextAttributeContent(XPathNavigator navigator) {
            if (navigator.NodeType == XPathNodeType.Attribute) {
                if (!navigator.MoveToNextAttribute()) { 
                    navigator.MoveToParent();
                    if (!navigator.MoveToFirstChild()) { 
                        // No children, so reposition on original attribute 
                        navigator.MoveToFirstAttribute();
                        while (navigator.MoveToNextAttribute()) 
                            ;
                        return false;
                    }
                } 
                return true;
            } 
            return navigator.MoveToNext(); 
        }
    } 
}

// File provided for Reference Use Only by Microsoft Corporation (c) 2007.
Link Menu

Network programming in C#, Network Programming in VB.NET, Network Programming in .NET
This book is available now!
Buy at Amazon US or
Buy at Amazon UK
XmlNavigatorFilter.cs source code in C# .NET

Source code for the .NET framework in C#

Code:

Link Menu
