How to parse XML file to get specific data effectively

Question

I have an XML file looks like this:

<?xml version="1.0" encoding="utf-8" ?> 
 <PathMasks>
 <Mask desc="Masks_X1">
  <config id="01" mask="88" /> 
  <config id="03" mask="80" /> 
  <config id="51" mask="85" /> 
  </Mask>

 <Mask desc="Masks_X2">
  <config id="70" mask="1" /> 
  <config id="73" mask="6" /> 
  </Mask>

 <Types>
  <path id="01" desc="TC->PP1" /> 
  <path id="02" desc="TC->PP2" /> 
  <path id="03" desc="TC->PPn" /> 
  </Types>
  </PathMasks>

How to parse the file and get all the data of Mask_X1 as following:

id  value
=====
01, 88
03, 80
51, 85

The .NET framework I am using is 2.0

Answer 1

Use XDocument and query into it with Linq to XML

XDocument doc = XDocument.Load("file.xml");
var linqtoxml = from node in document.Descendants("Mask")
    where (string)node.Attribute("desc").Value == "Masks_X1"
    select node;
foreach (var mask in linqtoxml)
{
    // pull data out of here into a structure of your choosing
}

Answer 2

Using Linq to XML :

XDocument doc = XDocument.Load(filename);
var query = from mask in doc.Root.Elements("Mask")
            where mask.Attribute("desc").Value == "Masks_X1"
            from config in mask.Elements("config")
            select new
            {
                id = config.Attribute("id").Value,
                value = config.Attribute("mask").Value
            };

foreach(var mask in query)
{
    Console.WriteLine("{0}\t{1}", mask.id, mask.value);
}

Answer 3

Hi,

As you're working with .Net 2.0 you won't have Linq and will therefore need to use XPath, this sample should help you out.

        XmlDocument doc = new XmlDocument();

        doc.Load(pathToXmlDoc);


        XmlNode node = doc.SelectSingleNode("/PathMasks/Mask[@desc='Masks_X1']");

        foreach (XmlNode config in node)
        {
            Console.WriteLine("{0}\t{1}", 
                            config.Attributes["id"].Value,
                            config.Attributes["mask"].Value);
        }

Answer 4

Using XmlDocument (slower, larger memory footprint, read/write, works the same way XML DOMs everywhere work):

XmlDocument d = new XmlDocument();
d.Load(filename);
string xpath = "/PathMasks/Mask[@desc='Mask_X1']/config"
foreach (XmlElement elm in d.SelectNodes(xpath))
{
   Console.WriteLine(elm.GetAttribute("id"), elm.GetAttribute("desc"));
}

Using XPathDocument (faster, smaller memory footprint, read-only, weird API):

XPathDocument d = new XPathDocument(filename);
string xpath = "/PathMasks/Mask[@desc='Mask_X1']/config"
XPathNodeIterator iter = d.CreateNavigator().Select(xpath);
while (iter.MoveNext())
{
   Console.WriteLine(iter.Current.GetAttribute("id"), iter.Current.GetAttribute("desc'));
}

I'm sure there's a perfectly good reason why there isn't a method of XPathNavigator that returns an IEnumerable<XPathNavigator> so that you can iterate over the results of an XPath query like a normal person, but I haven't been able to work it out.