Appending Node to Large XML File

[Jonathan Taylor]

I have a large XML file, that is too large to read in to XmlDocument.

I need to append data to this XML file without creating a new file, since I
don't want to have two copies of the large file on the server.

I've not seen any example that works so far, even with google. Can anyone
help ?

[Yingzi Le]

Hi Jonathan,

You can use XmlTextReader and XmlTextWriter. They're very fast. You can
programmatically delete the old file if you don't want to keep two large
files.

To start you can read through some documentations here:
http://msdn.microsoft.com/library/de...us/cpref/html/
frlrfsystemxmlxmltextwriterclasstopic.asp
http://msdn.microsoft.com/library/de...us/cpref/html/
frlrfsystemxmlxmltextreaderclassnodetypetopic.asp
http://msdn.microsoft.com/library/de...us/cpref/html/
frlrfsystemxmlxmltextwriterclasstopic.asp

The following are some sample code:

//reader the Large Xml file using XmlTextReader
XmlTextReader reader = new XmlTextReader(@"C:\Test\LargeXmlFile.xml");

//XmlTextWriter to write Large XML File
XmlTextWriter cdocWriter = new
XmlTextWriter(@"C:\Test\LargeXmlFile_New.xml", Encoding.UTF8);

writer.Formatting = Formatting.Indented;

writer.WriteStartDocument();

// Read the file and display each of the nodes.
while (reader.Read())
{
switch (reader.NodeType)
{
case XmlNodeType.Element:
writer.WriteStartElement(reader.Name);
writer.WriteAttributes(reader,false);
if (reader.IsEmptyElement)
writer.WriteEndElement();
break;
//You can have some test statement here to append nodes
if (reader.Name == "????")
{
//TODO: do something
}
case XmlNodeType.Text:
writer.WriteString(reader.Value);
break;
case XmlNodeType.Whitespace:
case XmlNodeType.SignificantWhitespace:
writer.WriteWhitespace(reader.Value);
break;
case XmlNodeType.CDATA:
writer.WriteCData(reader.Value);
break;
case XmlNodeType.Comment:
writer.WriteComment(reader.Value);
break;
case XmlNodeType.EntityReference:
writer.WriteEntityRef(reader.Name);
break;
case XmlNodeType.EndElement:
//You can have some test statement here to append nodes
if (reader.Name == "????")
{
//TODO: do something
}

writer.WriteEndElement();
break;
}
}

writer.WriteEndDocument();
writer.Flush();
writer.Close();
reader.Close();

Hope this helps!
--
Yingzi Le
LongHorn SDK Team

This posting is provided "AS IS" with no warranties, and confers no rights.

--------------------

From: "Jonathan Taylor" <jo****@00000000homtail.com>
Subject: Appending Node to Large XML File
Date: Fri, 20 May 2005 13:18:24 +0100
Lines: 9
X-Priority: 3
X-MSMail-Priority: Normal
X-Newsreader: Microsoft Outlook Express 6.00.2900.2527
X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2900.2527
X-RFC2646: Format=Flowed; Original
Message-ID: <#6**************@TK2MSFTNGP10.phx.gbl>
Newsgroups: microsoft.public.dotnet.xml
NNTP-Posting-Host: 82-41-12-138.cable.ubr02.edin.blueyonder.co.uk 82.41.12.138Path: TK2MSFTNGXA01.phx.gbl!TK2MSFTNGP08.phx.gbl!TK2MSFT NGP10.phx.gbl
Xref: TK2MSFTNGXA01.phx.gbl microsoft.public.dotnet.xml:7123
X-Tomcat-NG: microsoft.public.dotnet.xml

I have a large XML file, that is too large to read in to XmlDocument.

I need to append data to this XML file without creating a new file, since Idon't want to have two copies of the large file on the server.

I've not seen any example that works so far, even with google. Can anyone
help ?