XmlDocumentFragment.cs source code in C# .NET

Source code for the .NET framework in C#



/ FXUpdate3074 / FXUpdate3074 / 1.1 / untmp / whidbey / QFE / ndp / fx / src / Xml / System / Xml / Dom / XmlDocumentFragment.cs / 1 / XmlDocumentFragment.cs

//     Copyright (c) Microsoft Corporation.  All rights reserved.
// [....] 
// DocumentFragment is a "lightweight" or "minimal" 
// Document object. It is very common to want to be able to
// extract a portion of a document's tree or to create a new fragment of a 
// document. Imagine implementing a user command like cut or rearranging a
// document by moving fragments around. It is desirable to have an object
// which can hold such fragments and it is quite natural to use a Node for
// this purpose. While it is true that a Document object could 
// fulfil this role,  a Document object can potentially be a
// heavyweight  object, depending on the underlying implementation. What is 
// really needed for this is a very lightweight object. 
// DocumentFragment is such an object.

Furthermore, various operations -- such as inserting nodes as children // of another Node -- may take DocumentFragment // objects as arguments; this results in all the child nodes of the // DocumentFragment being moved to the child list of this node. //

The children of a DocumentFragment node are zero or more // nodes representing the tops of any sub-trees defining the structure of the // document. DocumentFragment nodes do not need to be // well-formed XML documents (although they do need to follow the rules // imposed upon well-formed XML parsed entities, which can have multiple top // nodes). For example, a DocumentFragment might have only one // child and that child node could be a Text node. Such a // structure model represents neither an HTML document nor a well-formed XML // document. //

When a DocumentFragment is inserted into a // Document (or indeed any other Node that may take // children) the children of the DocumentFragment and not the // DocumentFragment itself are inserted into the // Node. This makes the DocumentFragment very // useful when the user wishes to create nodes that are siblings; the // DocumentFragment acts as the parent of these nodes so that the // user can use the standard methods from the Node interface, // such as insertBefore() and appendChild(). namespace System.Xml { using System.Diagnostics; using System.Xml.XPath; // Represents a lightweight object that is useful for tree insert // operations. public class XmlDocumentFragment : XmlNode { XmlLinkedNode lastChild; protected internal XmlDocumentFragment( XmlDocument ownerDocument ): base( ) { if ( ownerDocument == null ) throw new ArgumentException(Res.GetString(Res.Xdom_Node_Null_Doc)); parentNode= ownerDocument; } // Gets the name of the node. public override String Name { get { return OwnerDocument.strDocumentFragmentName;} } // Gets the name of the current node without the namespace prefix. public override String LocalName { get { return OwnerDocument.strDocumentFragmentName;} } // Gets the type of the current node. public override XmlNodeType NodeType { get { return XmlNodeType.DocumentFragment;} } // Gets the parent of this node (for nodes that can have parents). public override XmlNode ParentNode { get { return null;} } // Gets the XmlDocument that contains this node. public override XmlDocument OwnerDocument { get { return (XmlDocument)parentNode; } } // Gets or sets the markup representing just // the children of this node. public override string InnerXml { get { return base.InnerXml; } set { RemoveAll(); XmlLoader loader = new XmlLoader(); //Hack that the content is the same element loader.ParsePartialContent( this, value, XmlNodeType.Element ); } } // Creates a duplicate of this node. public override XmlNode CloneNode(bool deep) { Debug.Assert( OwnerDocument != null ); XmlDocument doc = OwnerDocument; XmlDocumentFragment clone = doc.CreateDocumentFragment(); if (deep) clone.CopyChildren( doc, this, deep ); return clone; } internal override bool IsContainer { get { return true;} } internal override XmlLinkedNode LastNode { get { return lastChild;} set { lastChild = value;} } internal override bool IsValidChildType( XmlNodeType type ) { switch (type) { case XmlNodeType.Element: case XmlNodeType.Text: case XmlNodeType.EntityReference: case XmlNodeType.Comment: case XmlNodeType.Whitespace: case XmlNodeType.SignificantWhitespace: case XmlNodeType.ProcessingInstruction: case XmlNodeType.CDATA: return true; case XmlNodeType.XmlDeclaration: //if there is an XmlDeclaration node, it has to be the first node; XmlNode firstNode = FirstChild; if (firstNode == null || firstNode.NodeType != XmlNodeType.XmlDeclaration) return true; else return false; //not allowed to insert a second XmlDeclaration node default: return false; } } internal override bool CanInsertAfter( XmlNode newChild, XmlNode refChild ) { Debug.Assert(newChild != null); //should be checked that newChild is not null before this function call if (newChild.NodeType == XmlNodeType.XmlDeclaration) { if (refChild == null) { //append at the end return (LastNode == null); } else return false; } return true; } internal override bool CanInsertBefore( XmlNode newChild, XmlNode refChild ) { Debug.Assert(newChild != null); //should be checked that newChild is not null before this function call if (newChild.NodeType == XmlNodeType.XmlDeclaration) { return (refChild==null || refChild==FirstChild); } return true; } // Saves the node to the specified XmlWriter. public override void WriteTo(XmlWriter w) { WriteContentTo( w ); } // Saves all the children of the node to the specified XmlWriter. public override void WriteContentTo(XmlWriter w) { foreach( XmlNode n in this ) { n.WriteTo( w ); } } internal override XPathNodeType XPNodeType { get { return XPathNodeType.Root; } } } } // File provided for Reference Use Only by Microsoft Corporation (c) 2007. // Copyright (c) Microsoft Corporation. All rights reserved.

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