Given the code:
var doc = new XmlDocument();
doc.LoadXml(#"<a>
<b>test
<c>test2</c>
</b>
</a>");
var node = doc.SelectNodes("/a/b")[0];
I want to then extract the 'text' value of node b - in this case "test", without retrieving all text elements from all child nodes (as .innerText does)
I find myself resorting to this code
var elementText = node.ChildNodes.Cast<XmlNode>().First(a => a.NodeType == XmlNodeType.Text).Value;
As unfortunately node.Value does something else in this case
is there a neater/inbuilt way without resorting to linq casting? that doesnt involve me doing something like;
foreach (var childNode in node.ChildNodes)
if (childNode.NodeType==XmlNodeType.Text)
...
I prefer XDocument to XmlDocument, I think it's easier to work with. You can easily get a value using the Element method to find the "b" element, and then using the Value property.
using(var stream = new MemoryStream())
{
using(var streamWriter = new StreamWriter(stream))
{
streamWriter.Write(#"<a>
<b>test
<c>test2</c>
</b>
</a>");
streamWriter.Flush();
streamWriter.BaseStream.Seek(0, SeekOrigin.Begin);
var doc = XDocument.Load(stream);
Console.WriteLine(doc.Element("a").Element("b").FirstNode.ToString());
}
}
EDIT: As noted in comments, that would get the incorrect value. I've updated it correctly.
In LINQ2XML you can do this
foreach(XNode elm in doc.Descendants("b").OfType<XText>())
{
//elm has the text
}
You want to use node.InnerText instead of Value. So you would have this:
foreach(XmlNode child in node.ChildNodes)
{
if (string.IsNullOrEmpty(s))
{
s = child.InnerText;
}
else
{
s = s.Replace(child.InnerText, "");
}
}
s.Trim();
Related
Is there a way I can reduce the foreach code below so I don't have to use a foreach loop to iterate over the xml nodes?
I just want to look and see if an item is present in the xml file
XmlDocument doc = new XmlDocument();
doc.Load("MyList.xml");
XmlNodeList list = doc.SelectNodes("/MyList/item");
foreach( XmlNode item in list)
{
string name = item.InnerText;
if(name == "blah blah")
{
//do something
}
}
The above works but I just want a smaller cooler way of doing it :)
If all you want to do is check whether a certain node exists, use SelectSingleNode with a filtered XPath:
XmlNode node = doc.SelectSingleNode("/MyList/item[. = 'blah blah']");
if (node != null)
{
// do something
}
One issue here is that if the value you want to match on is a dynamic value, you should not build up the XPath by concatenating strings together. That would create an invalid XPath.
In that case, you can either use LINQ on an XmlNodeList:
var found = doc.SelectSingleNode("/MyList/item")
.Cast<XmlNode>()
.Any(n => n.InnerText == "blah blah");
or go ahead and use LINQ-to-XML:
XDocument doc = XDocument.Load("MyList.xml");
bool itemFound = doc.Element("MyList")
.Elements("item")
.Any(e => (string) e == "blah blah");
You can filter element by inner text directly in the XPath expression like so :
XmlNodeList list = doc.SelectNodes("/MyList/item[.='blah blah']");
I have a XML file which contains about 850 XML nodes. Like this:
<NameValueItem>
<Text>Test</Text>
<Code>Test</Code>
</NameValueItem>
........ 849 more
And I want to add a new Childnode inside each and every Node. So I end up like this:
<NameValueItem>
<Text>Test</Text>
<Code>Test</Code>
<Description>TestDescription</Description>
</NameValueItem>
........ 849 more
I've tried the following:
XmlDocument doc = new XmlDocument();
doc.Load(xmlPath);
XmlNodeList nodes = doc.GetElementsByTagName("NameValueItem");
Which gives me all of the nodes, but from here am stuck(guess I need to iterate over all of the nodes and append to each and every) Any examples?
You need something along the lines of this example below. On each of your nodes, you need to create a new element to add to it. I assume you will be getting different values for the InnerText property, but I just used your example.
foreach (var rootNode in nodes)
{
XmlElement element = doc.CreateElement("Description");
element.InnerText = "TestDescription";
root.AppendChild(element);
}
You should just be able to use a foreach loop over your XmlNodeList and insert the node into each XmlNode:
foreach(XmlNode node in nodes)
{
node.AppendChild(new XmlNode()
{
Name = "Description",
Value = [value to insert]
});
}
This can also be done with XDocument using LINQ to XML as such:
XDocument doc = XDocument.Load(xmlDoc);
var updated = doc.Elements("NameValueItem").Select(n => n.Add(new XElement() { Name = "Description", Value = [newvalue]}));
doc.ReplaceWith(updated);
If you don't want to parse XML using proper classes (i.e. XDocument), you can use Regex to find a place to insert your tag and insert it:
string s = #"<NameValueItem>
<Text>Test</Text>
<Code>Test</Code>
</NameValueItem>";
string newTag = "<Description>TestDescription</Description>";
string result = Regex.Replace(s, #"(?<=</Code>)", Environment.NewLine + newTag);
but the best solution is Linq2XML (it's much better, than simple XmlDocument, that is deprecated at now).
string s = #"<root>
<NameValueItem>
<Text>Test</Text>
<Code>Test</Code>
</NameValueItem>
<NameValueItem>
<Text>Test2</Text>
<Code>Test2</Code>
</NameValueItem>
</root>";
var doc = XDocument.Load(new StringReader(s));
var elms = doc.Descendants("NameValueItem");
foreach (var element in elms)
{
element.Add(new XElement("Description", "TestDescription"));
}
var text = new StringWriter();
doc.Save(text);
Console.WriteLine(text);
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
I have a DataGridView control where some values are popluted.
And also I have an xml file. The user can change the value in the Warning Column of DataGridView.And that needs to be saved in the xml file.
The below program just does the job
XDocument xdoc = XDocument.Load(filePath);
//match the record
foreach (var rule in xdoc.Descendants("Rule"))
{
foreach (var row in dgRulesMaster.Rows.Cast<DataGridViewRow>())
{
if (rule.Attribute("id").Value == row.Cells[0].Value.ToString())
{
rule.Attribute("action").Value = row.Cells[3].Value.ToString();
}
}
}
//save the record
xdoc.Save(filePath);
Matching the grid values with the XML document and for the matched values, updating the needed XML attribute.
Is there a better way to code this?
Thanks
You could do something like this:
var rules = dgRulesMaster.Rows.Cast<DataGridViewRow>()
.Select(x => new {
RuleId = x.Cells[0].Value.ToString(),
IsWarning = x.Cells[3].Value.ToString() });
var tuples = from n in xdoc.Descendants("Rule")
from r in rules
where n.Attribute("id").Value == r.RuleId
select new { Node = n, Rule = r };
foreach(var tuple in tuples)
tuple.Node.Attribute("action").Value = tuple.Rule.IsWarning;
This is basically the same, just a bit more LINQ-y. Whether or not this is "better" is debatable. One thing I removed is the conversion of IsWarning first to string, then to int and finally back to string. It now is converted to string once and left that way.
XPath allows you to target nodes in the xml with alot of power. Microsoft's example of using the XPathNavigator to modify an XML file is as follows:
XmlDocument document = new XmlDocument();
document.Load("contosoBooks.xml");
XPathNavigator navigator = document.CreateNavigator();
XmlNamespaceManager manager = new XmlNamespaceManager(navigator.NameTable);
manager.AddNamespace("bk", "http://www.contoso.com/books");
foreach (XPathNavigator nav in navigator.Select("//bk:price", manager))
{
if (nav.Value == "11.99")
{
nav.SetValue("12.99");
}
}
Console.WriteLine(navigator.OuterXml);
Source: http://msdn.microsoft.com/en-us/library/zx28tfx1(v=vs.80).aspx
This is part of the input string, i can't modify it, it will always come in this way(via shared memory), but i can modify after i have put it into a string of course:
<sys><id>SCPUCLK</id><label>CPU Clock</label><value>2930</value></sys><sys><id>SCPUMUL</id><label>CPU Multiplier</label><value>11.0</value></sys><sys><id>SCPUFSB</id><label>CPU FSB</label><value>266</value></sys>
i've read it with both:
String.Concat(
XElement.Parse(encoding.GetString(bytes))
.Descendants("value")
.Select(v => v.Value));
and:
XmlDocument document = new XmlDocument();
document.LoadXml(encoding.GetString(bytes));
XmlNode node = document.DocumentElement.SelectSingleNode("//value");
Console.WriteLine("node = " + node);
but they both have an error when run; that the input has multiple roots(There are multiple root elements quote), i don't want to have to split the string.
Is their any way to read the string take the value between <value> and </value> without spiting the string into multiple inputs?
That's not a well-formed XML document, so most XML tools won't be able to process it.
An exception is the XmlReader. Look up XmlReaderSettings.ConformanceLevel in MSDN. If you set it to ConformanceLevel.Fragment, you can create an XmlReader with those settings and use it to read elements from a stream that has no top-level element.
You have to write code that uses XmlReader.Read() to do this - you can't just feed it to an XmlDocument (which does require that there be a single top-level element).
e.g.,
var readerSettings = new XmlReaderSettings { ConformanceLevel = ConformanceLevel.Fragment };
using (var reader = XmlReader.Create(stream, readerSettings))
{
while (reader.Read())
{
using (var fragmentReader = reader.ReadSubtree())
{
if (fragmentReader.Read())
{
var fragment = XNode.ReadFrom(fragmentReader) as XElement;
// do something with fragment
}
}
}
}
XML elements must have ONE root element, with whatever child structure you want.
Your xml string looks like:
<sys>
...
</sys>
<sys>
...
</sys>
The valid version would be:
<someRootElement>
<sys>
...
</sys>
<sys>
...
</sys>
</someElement>
Try:
XmlDocument document = new XmlDocument();
document.LoadXml("<root>"+encoding.GetString(bytes)+"</root>");
XmlNode node = document.DocumentElement.SelectSingleNode("//value");
Console.WriteLine("node = " + node);
This solution parses successfully all node types, including text nodes:
var settings = new XmlReaderSettings{ConformanceLevel = ConformanceLevel.Fragment};
var reader = XmlReader.Create(stream, settings);
while(reader.Read())
{
while(reader.NodeType != XmlNodeType.None)
{
if(reader.NodeType == XmlNodeType.XmlDeclaration)
{
reader.Skip();
continue;
}
XNode node = XNode.ReadFrom(reader);
}
}
Skips the XML declaration because it isn't a node.