XML Question

[Michael C]

Hi all,

I'm back with another XML question. We covered this briefly before, but I'm
still having problems with it. Basically what I need to do is be able to
add, delete and update nodes and their attributes in an XML file. Here's a
sample of an XML file I might use:

<root>
<settings>
<setting name="timeout">50</setting>
<setting name="loginattempts">3</setting>
</settings>
<servers>
<server name="sql1" username="sa" password="password"/>
<server name="sql2" username="user" password="upassword"/>
</servers>
</root>

I need to change the values of the <setting> nodes by name and add/delete or
modify the <server> tag attributes. As it stands right now, I read in the
entire file using an XmlTextReader; and when I update it, I re-write the
entire file using a StreamWriter. Can someone post, or direct me to, some
sample code that can get me on the road to properly using my XML file?
Meanwhile, I'll just be hitting the books

Thanks in advance,
Michael C.

 

[Desi Cortez]

Hi all,

I'm back with another XML question. We covered this briefly before, but
I'm
still having problems with it. Basically what I need to do is be able to
add, delete and update nodes and their attributes in an XML file. Here's
a sample of an XML file I might use:

<root>
<settings>
<setting name="timeout">50</setting>
<setting name="loginattempts">3</setting>
</settings>
<servers>
<server name="sql1" username="sa" password="password"/>
<server name="sql2" username="user" password="upassword"/>
</servers>
</root>

I need to change the values of the <setting> nodes by name and add/delete
or
modify the <server> tag attributes. As it stands right now, I read in the
entire file using an XmlTextReader; and when I update it, I re-write the
entire file using a StreamWriter. Can someone post, or direct me to, some
sample code that can get me on the road to properly using my XML file?
Meanwhile, I'll just be hitting the books

Thanks in advance,
Michael C.

You should be able to just load it and save it using those methods of the
XmlDocument class.

XmlDocument xd = new XmlDocument()
xd.Load("MyDoc.xml");
xd.Save("MyDoc.xml");

Now as far as modifying the value, use the innerText property after getting
to the node you want. You can set its value. The attributes are a
collection of the node. You can set those as well, one you've iterated
through them.

Alternatively, create an XPath query to retrieve the node and do the above.
I wrote a Windows service that does some of what you are asking.

Here's some sample code:

using System;
using System.Xml;

namespace xmltest{
class xpathtest1
{
[STAThread]
static void Main(string[] args)
{
if(args.Length < 2)
{
Console.WriteLine("Incorrect number of parameters.");
goto endApp;
}

try
{
//Load the XML document
XmlDocument doc = new XmlDocument();
doc.Load(args[0]);

//Select the nodes
XmlNodeList resultNodes = doc.SelectNodes(args[1]);
Console.WriteLine("{0} matching nodes found...",
resultNodes.Count);

//Print the node values
int iCount = 0;
foreach(XmlNode aNode in resultNodes)
Console.WriteLine("Node {0} value: {1}",
++iCount, aNode.InnerText);
}
catch(Exception exp)
{
Console.WriteLine("Error: " + exp.ToString());
}

endApp:
Console.Write("Press Enter to continue...");
Console.ReadLine();

}
}
}