Creating Other Node Types

Of course, the XmlDocument class provides methods for creating every node type. Table 11.2 lists the additional System.Xml.XmlNodeTypes and their corresponding creation methods.

Table 11.2. Other XmlNodeTypes and Their Creation Methods

NODETYPE	CREATION METHOD
CDATA	CreateCDataSection(string data)
Comment	CreateComment(string data)
DocumentFragment	CreateDocumentFragment()
EntityReference	CreateEntityReference(string name )
ProcessingInstruction	CreateProcessingInstruction(string target, string data)
Whitespace	CreateWhitespace(string ws)
Text	CreateTextNode(string text)
SignificantWhitespace	CreateSignificantWhitespace(string ws)

The CreateEntityReference method must be handled with care. The method will accept any legal name that can be used to create an EntityReference node. This entity reference will be written out when the document is saved. The catch is that unless the name parameter is equal to one of the general entities ( gt , lt , apos , quot , amp ), a NotSupportedException will be raised when the document is loaded back into an XmlDocument . Listing 11.20 will raise an exception at line 9 because of this.

Listing 11.20

 C# XmlDocument doc = new XmlDocument(); XmlElement ele = doc.CreateElement("", "root", ""); doc.AppendChild(ele); ele.AppendChild(doc.CreateEntityReference("entity")); doc.Save("blah.xml"); XmlDocument doc2 = new XmlDocument(); doc.Load(new StreamReader("blah.xml")); string val = doc.DocumentElement.FirstChild.Value; VB Dim doc As New XmlDocument() Dim ele As doc.CreateElement("", "root", "") doc.AppendChild(ele) ele.AppendChild(doc.CreateEntityReference("entity")) doc.Save("blah.xml") Dim doc2 As New XmlDocument(); doc.Load(New StreamReader("blah.xml")) Dim val As doc.DocumentElement.FirstChild.Value;