Develop Reference

XML Node Attribute returning as NULL when populated?

I have a XML Doc that I'm pulling out a specific Node and all of it's attributes. In debug mode I can see that I'm getting the specific Nodes and all of their attributes. However, when I try to get the attribute value it can't find it and returns a NULL value. I've done some searching and looked at some examples and from what I can tell I should be getting the value but I'm not and I don't see what I'm doing wrong.
I'm trying to get the StartTime value.
Here is the XML that is returned.
Here you can see in debug and with the Text Visualizer the value should be there.
The code I'm trying.
XmlNodeList nodes = xmlDoc.GetElementsByTagName("PlannedAbsences");
if (nodes != null && nodes.Count > 0)
{
foreach (XmlNode node in nodes)
{
if (node.Attributes != null)
{
var nameAttribute = node.Attributes["StartTime"];
if (nameAttribute != null)
{
//var startDate = nameAttribute.Value;
}
}
}
}

Using the XDocument class contained within the System.Xml.Linq namespace, grab the sub elements from the PlannedAbsences parent, then iterate over sub elements retrieving the value of the desired attribute.
var xmlDoc = XDocument.Load(#"path to xml file")
var absences = xmlDoc.Element("PlannedAbsences")?.Elements("Absence");
foreach (var item in absences)
{
var xElement = item.Attribute("StartTime").Value;
Console.WriteLine(xElement);
}

XDocument, it says that a node is text but it is an element

I am reading an XML that contains a tag like this:
<source><bpt id="1"><donottranslate></bpt><ph id="2">($ T_353_1 Parent ID $)</ph><ept id="1"></donottranslate></ept></source>
When reading source node I get that this node type is Text, but it should be Element.
This is an XML that I am receiving and I cannot change it.
Do you know how can I get this sorted out?
This is my code:
XDocument doc = XDocument.Load(fileName, LoadOptions.PreserveWhitespace);
foreach (var elUnit in doc.Descendants("trans-unit"))
{
if (elUnit.AttributeString("translate").ToString() == "no")
{
foreach (var elSource in elUnit.Elements("source"))
{
string text = "";
foreach (var node in elSource.DescendantNodes().Where(n => XmlNodeType.Text == n.NodeType).ToList())
{
//When reading that "source" node, it enters inside this code
Thanks

First check whether your XML is wellformed
http://www.w3schools.com/xml/xml_validator.asp
http://chris.photobooks.com/xml/default.htm
I could get this to work
//using System.Xml.Linq;
var str = "<source><bpt id=\"1\"><donottranslate></bpt>" +
"<ph id=\"2\">($ T_353_1 Parent ID $)</ph>" +
"<ept id=\"1\"></donottranslate></ept></source>";
XElement element = XElement.Parse(str);
Console.WriteLine(element);
The output is this
<source>
<bpt id="1"><donottranslate></bpt>
<ph id="2">($ T_353_1 Parent ID $)</ph>
<ept id="1"></donottranslate></ept>
</source>
Please provide some code sample for more help if this example if not suffient.

Finally, I solved this checking if the node is correct or not:
if (System.Security.SecurityElement.IsValidText(text.XmlDecodeEntities()))

How to iterate a xml file with XmlReader class

my xml stored in xml file which look like as below
<?xml version="1.0" encoding="utf-8"?>
<metroStyleManager>
<Style>Blue</Style>
<Theme>Dark</Theme>
<Owner>CSRAssistant.Form1, Text: CSR Assistant</Owner>
<Site>System.ComponentModel.Container+Site</Site>
<Container>System.ComponentModel.Container</Container>
</metroStyleManager>
this way i am iterating but some glitch is there
XmlReader rdr = XmlReader.Create(System.IO.Path.GetDirectoryName(System.Windows.Forms.Application.ExecutablePath) + #"\Products.xml");
while (rdr.Read())
{
if (rdr.NodeType == XmlNodeType.Element)
{
string xx1= rdr.LocalName;
string xx = rdr.Value;
}
}
it is always getting empty string xx = rdr.Value;
when element is style then value should be Blue as in the file but i am getting always empty....can u say why?
another requirement is i want to iterate always within <metroStyleManager></metroStyleManager>
can anyone help for the above two points. thanks

Blue is the value of Text node, not of Element node. You either need to add another if to get value of text nodes, or you can read inner xml of current element node:
rdr.MoveToContent();
while (rdr.Read())
{
if (rdr.NodeType == XmlNodeType.Element)
{
string name = rdr.LocalName;
string value = rdr.ReadInnerXml();
}
}
You can also use Linq to Xml to get names and values of root children:
var xdoc = XDocument.Load(path_to_xml);
var query = from e in xdoc.Root.Elements()
select new {
e.Name.LocalName,
Value = (string)e
};

You can use the XmlDocument class for this.
XmlDocument doc = new XmlDocument.Load(filename);
foreach (XmlNode node in doc.ChildNodes)
{
if (node.ElementName == "metroStyleManager")
{
foreach (XmlNode subNode in node.ChildNodes)
{
string key = subNode.LocalName; // Style, Theme, etc.
string value = subNode.Value; // Blue, Dark, etc.
}
}
else
{
...
}
}

you can user XDocument xDoc = XDocument.Load(strFilePath) to load XML file.
then you can use
foreach (XElement xeNode in xDoc.Element("metroStyleManager").Elements())
{
//Check if node exist
if (!xeNode.Elements("Style").Any()
//If yes then
xeNode.Value
}
Hope it Helps...
BTW, its from System.XML.Linq.XDocument

Removing XML node

I have got yet another task I am not able to accomplish: I am supposed to parse the XML from this site, remove all the nodes that don't have "VIDEO" in their name and then save it to another XML file. I have no problems with reading and writing, but removing makes me some difficulties. I have tried to do the Node -> Parent Node -> Child Node work-aroud, but it did not seem useful:
static void Main(string[] args)
{
using (WebClient wc = new WebClient())
{
string s = wc.DownloadString("http://feeds.bbci.co.uk/news/health/rss.xml");
XmlElement tbr = null;
XmlDocument xml = new XmlDocument();
xml.LoadXml(s);
foreach (XmlNode node in xml["rss"]["channel"].ChildNodes)
{
if (node.Name.Equals("item") && node["title"].InnerText.StartsWith("VIDEO"))
{
Console.WriteLine(node["title"].InnerText);
}
else
{
node.ParentNode.RemoveChild(node);
}
}
xml.Save("NewXmlDoc.xml");
Console.WriteLine("\nDone...");
Console.Read();
}
}
I have also tried the RemoveAll method, which does not work as well, because it removes all the nodes not satisfying the "VIDEO" condition.
//same code as above, just the else statement is changed
else
{
node.RemoveAll();
}
Could you help me, please?

I find Linq To Xml easier to use
var xDoc = XDocument.Load("http://feeds.bbci.co.uk/news/health/rss.xml");
xDoc.Descendants("item")
.Where(item => !item.Element("title").Value.StartsWith("VIDEO"))
.ToList()
.ForEach(item=>item.Remove());
xDoc.Save("NewXmlDoc.xml");
You can also use XPath
foreach (var item in xDoc.XPathSelectElements("//item[not(starts-with(title,'VIDEO:'))]")
.ToList())
{
item.Remove();
}

Update or inserting a node in an XML doc

I am a beginner to XML and XPath in C#. Here is an example of my XML doc:
<root>
<folder1>
...
<folderN>
...
<nodeMustExist>...
<nodeToBeUpdated>some value</nodeToBeUpdated>
....
</root>
What I need is to update the value of nodeToBeUdpated if the node exists or add this node after the nodeMustExist if nodeToBeUpdated is not there. The prototype of the function is something like this:
void UpdateNode(
xmlDocument xml,
string nodeMustExist,
string nodeToBeUpdte,
string newVal
)
{
/*
search for XMLNode with name = nodeToBeUpdate in xml
to XmlNodeToBeUpdated (XmlNode type?)
if (xmlNodeToBeUpdated != null)
{
xmlNodeToBeUpdated.value(?) = newVal;
}
else
{
search for nodeMustExist in xml to xmlNodeMustExist obj
if ( xmlNodeMustExist != null )
{
add xmlNodeToBeUpdated as next node
xmlNodeToBeUpdte.value = newVal;
}
}
*/
}
Maybe there are other better and simplified way to do this. Any advice?
By the way, if nodeToBeUpdated appears more than once in other places, I just want to update the first one.

This is to update all nodes in folder:
public void UpdateNodes(XmlDocument doc, string newVal)
{
XmlNodeList folderNodes = doc.SelectNodes("folder");
if (folderNodes.Count > 0)
foreach (XmlNode folderNode in folderNodes)
{
XmlNode updateNode = folderNode.SelectSingleNode("nodeToBeUpdated");
XmlNode mustExistNode = folderNode.SelectSingleNode("nodeMustExist"); ;
if (updateNode != null)
{
updateNode.InnerText = newVal;
}
else if (mustExistNode != null)
{
XmlNode node = folderNode.OwnerDocument.CreateNode(XmlNodeType.Element, "nodeToBeUpdated", null);
node.InnerText = newVal;
folderNode.AppendChild(node);
}
}
}
If you want to update a particular node, you cannot pass string nodeToBeUpdte, but you will have to pass the XmlNode of the XmlDocument.
I have omitted the passing of node names in the function since nodes names are unlikely to change and can be hardcoded. However, you can pass these to the functions and use the strings instead of hardcoded node names.

The XPath expression that selects all instances of <nodeToBeUpdated> would be this:
/root/folder[nodeMustExist]/nodeToBeUpdated
or, in a more generic form:
/root/folder[*[name() = 'nodeMustExist']]/*[name() = 'nodeToBeUpdated']
suitable for:
void UpdateNode(xmlDocument xml,
string nodeMustExist,
string nodeToBeUpdte,
string newVal)
{
string xPath = "/root/folder[*[name() = '{0}']]/*[name() = '{1}']";
xPath = String.Format(xPath, nodeMustExist, nodeToBeUpdte);
foreach (XmlNode n in xml.SelectNodes(xPath))
{
n.Value = newVal;
}
}

Have a look at the SelectSingleNode method MSDN Doc
your xpath wants to be something like "//YourNodeNameHere" ;
once you have found that node you can then traverse back up the tree to get to the 'nodeMustExist' node:
XmlNode nodeMustExistNode = yourNode.Parent["nodeMustExist];