I have an XML file with the following structure:
<Definitions>
<Definition Execution="Firstkey" Name="Somevalue"></Definition>
<Definition Execution="Secondkey" Name="Someothervalue"></Definition>
</Definitions>
How can I get the values of the keys (Firstkey, Secondkey) and write them down using C# in my .NET application?
Thanks.
Using Linq to XML this is straightforward.
To just get the keys:
var keys = doc.Descendants("Definition")
.Select(x => x.Attribute("Execution").Value);
foreach (string key in keys)
{
Console.WriteLine("Key = {0}", key);
}
To get all values:
XDocument doc = XDocument.Load("test.xml");
var definitions = doc.Descendants("Definition")
.Select(x => new { Execution = x.Attribute("Execution").Value,
Name = x.Attribute("Name").Value });
foreach (var def in definitions)
{
Console.WriteLine("Execution = {0}, Value = {1}", def.Execution, def.Name);
}
Edit in response to comment:
I think what you really want is a dictionary, that maps from a key ("Execution") to a value ("Name"):
XDocument doc = XDocument.Load("test.xml");
Dictionary<string, string> dict = doc.Descendants("Definition")
.ToDictionary(x => x.Attribute("Execution").Value,
x => x.Attribute("Name").Value);
string firstKeyValue = dict["Firstkey"]; //Somevalue
using System.Xml.Linq;
var keys = XDocument.Load("path to the XML file")
.Root
.Elements()
.Select(x => x.Attribute("Execution"));
Using XMLDocumnet/XMLNode(s):
//Load the XML document into memory
XmlDocument doc = new XmlDocument();
doc.Load("myXML.xml");
//get a list of the Definition nodes in the document
XmlNodeList nodes = doc.GetElementsByTagName("Definition");
//loop through each node in the XML
foreach (XmlNode node in nodes)
{
//access the key attribute, since it is named Execution,
//that is what I pass as the index of the attribute to get
string key = node.Attributes["Execution"].Value;
//To select a single node, check if we have the right key
if(key == "SecondKey") //then this is the second node
{
//do stuff with it
}
}
basically you load the xml into a document variable, select the nodes you wish to view. Then iterate through them and store pertinent information.
XPath would be a great choice, I'd say.
Below is a sample XPath expression.
//Definition[#Execution='Firstkey']/#Name
As a XPath expression is a string, you can easily replace 'Firstkey' with whatever you need.
Use this with a XmlDocument.SelectSingleNode or XmlDocument.SelectNodes method
Both the above mentioned methods return an XmlNode. You can easily access the XmlNode.Value
Here are some XPath expressions
Don't forget XPath Visualizer which makes working with XPath so much easier!
Related
I have an XML document containing processing instructions. I know that, with the XmlDocument class, you can use
var node = xmlDoc.SelectSingleNode("processing-instruction('xml-stylesheet')") as XmlProcessingInstruction;
but I want to use XDocument. How can I do this?
This is how I access an XML file's nodes with the XDocument class.
However, you'll have to be more specific on what you want to do with it.
XDocument doc = XDocument.Load("filepath");
var node = doc.Nodes().OfType<XElement>().SingleOrDefault(n => n.Name == "node name");
var node_value = node.Value;
var node_descendants = node.Descendants();
UPDATE:
As you may have noticed there's no SelectSingleNode in XDocument, in fact, to retrieve the node you want you'll have to fetch it from the corresponding ienumerable collection, or alternatively from the predefined FirstNode, NextNode, PreviousNode, LastNode, but you cannot apply any filters to those. Therefore the only ways to retrieve ProcessingInstruction nodes are
var pI_nodes = doc.Nodes().OfType<XProcessingInstruction>();
And
var pI_nodes = (from node in doc.Nodes()
where node.NodeType == System.Xml.XmlNodeType.ProcessingInstruction
select node);
If you expect to retrieve several ProcessingInstructions and need to filter these as well, the equivalent to the node name would the Target property
var filtered_pIs = pI_nodes_1.Where(pI => pI.Target == "xml-stylesheet");
And as a final reminder the value of the processing instruction is stored in the Data property.
string pI_value = filtered_pIs.First().Data
Here is one way:
var node = xDoc.Root.Nodes().OfType<XProcessingInstruction>().First();
I have an XML file with a structure similar to this
<entry name="something">
<members>
<member>aaa</member>
<member>bbb</member>
</members>
</entry>
<entry name="something_else">
<members>
<member>ccc</member>
<member>ddd</member>
</members>
</entry>
I need to be able to get the values out of each of the member nodes to store in a datatable. if i use the innertext property, it concatenates the values (aaabbb). there is nothing discernible to split the string on. I can also use the inner XML but then i just get a string with the XML structure (aaa bbb<\member>)
What is the best way to get each value out of the XML elements and store it in a string array?
here is what I have been trying.
foreach (XmlNode grpNode in GrpList)
{
subNode = grpNode.Attributes["name"];
if (subNode != null)
{
Obj = grpNode.Attributes["name"].Value;
}
subNode = grpNode["members"];
if (subNode != null)
{
string innerXml = string.Empty;
innerXml = grpNode["members"].InnerXml.ToString();
string[] tempArrary = innerXml.Split(new char[] {'>', '<'});
}
}
You can use Xpath to iterate through Entry nodes and get the members within it like this
string xml = "<root><entry name='something'>" +
"<members>" +
"<member>aaa</member>" +
"<member>bbb</member>" +
"</members>" +
"</entry>" +
"<entry name='something_else'>" +
"<members>" +
"<member>ccc</member>" +
"<member>ddd</member>" +
"</members>" +
"</entry></root>";
XmlDocument doc = new XmlDocument();
doc.LoadXml(xml);
var memsList = doc.SelectNodes("//entry");
foreach (XmlNode a in memsList)
{
Console.WriteLine(a.Attributes["name"].Value);
var memList = a.SelectNodes("members/member");
foreach(XmlNode x in memList)
Console.WriteLine(x.InnerText);
}
You need to iterate the child elements within members, so something like:
foreach (var node in grpNode["members"].ChildNodes)
{
var value = node.InnerText;
}
That said, you would be better off using LINQ to XML unless you have some specific reason to use XmlDocument. This gives you much more expressive code, for example:
var doc = XDocument.Parse(xml);
var something = doc.Descendants("entry")
.Where(e => (string)e.Attribute("name") == "something")
.Single();
var somethingMembers = something.Descendants("member")
.Select(e => e.Value)
.ToArray();
This should do the trick:
XDocument xdoc = XDocument.Load(#"Path/to/file");
var result = xdoc.Descendants("member").Select (x => x.Value).ToArray();
Result:
Demo Code
the xml you've provided isn't valid. But assuming you just want the inner text of all member nodes into a string array, I'd just use Linq-To-Xml (XDocument):
var results = XDocument.Parse(xmlString)
.Descendants("member")
.Select(m => m.Value)
.ToArray();
Even though you're using the old XmlDocument API, by throwing in an .OfType<XmlNode>() you can convert an XmlNodeList to a generic enumerable and thereby mix in some linq and lambda syntax, for instance:
var tempArrary = subNode.SelectNodes("member").OfType<XmlNode>().Select(n => n.InnerText).ToArray();
I want to check that if the "< city>" node 'having a specific value (say Pathankot )' already exist in the xml file under the a particular "< user Id="any"> having a specific Id", before inserting a new city node into the xml.
< users>
< user Id="4/28/2015 11:29:44 PM">
<city>Fazilka</city>
<city>Pathankot </city>
<city>Jalandher</city>
<city>Amritsar</city>
</user>
</users>
In order to insert I am using the Following c# code
XDocument xmlDocument = XDocument.Load(#"C:\Users\Ajax\Documents\UserSelectedCity.xml");
string usrCookieId = Request.Cookies["CookieId"].Value;
xmlDocument.Element("Users")
.Elements("user")
.Single(x => (string)x.Attribute("Id") == usrCookieId)
//Incomplete because same named cities can be entered more that once
//need to make delete function
.Add(
new XElement("city", drpWhereToGo.SelectedValue));
My Questions:
How Can i check weather the < city> node having specific value say
Pathankot already exist in the xml file Before Inserting a new city
node.
I am Using absolute Path in" XDocument xmlDocument =
XDocument.Load(#"C:\Users\Ajax\Documents\Visual Studio
2012\WebSites\punjabtourism.com\UserSelectedCity.xml");" This
does not allow me to move the files to new folder without changing
the path which is not desirable. But if i use the relative path The
Error Occures "Access Denied";
I would use this simple approach:
var query =
xmlDocument
.Root
.Elements("user")
.Where(x => x.Attribute("Id").Value == usrCookieId)
.Where(x => !x.Elements("city").Any(y => y.Value == "Pathankot"));
foreach (var xe in query)
{
xe.Add(new XElement("city", drpWhereToGo.SelectedValue));
}
It's best to avoid using .Single(...) or .First(...) if possible. The description of your problem doesn't sound like you need to use these though.
Try this:-
First load the XML file into XDocument object by specifying the physical path where your XML file is present. Once you have the object just take the First node with matching condition (please note I am using First instead of Single cz you may have multiple nodes with same matching condition, Please see the Difference between Single & First)
XDocument xmlDocument = XDocument.Load(#"YourPhysicalPath");
xmlDocument.Descendants("user").First(x => (string)x.Attribute("Id") == "1"
&& x.Elements("city").Any(z => z.Value.Trim() == "Pathankot"))
.Add(new XElement("city", drpWhereToGo.SelectedValue));
xmlDocument.Save("YourPhysicalPath");
Finally add the required city to the node retrieved from the query and save the XDocument object.
Update:
If you want to check first if all the criteria fulfills then simply use Any like this:-
bool isCityPresent = xdoc.Descendants("user").Any(x => (string)x.Attribute("Id") == "1"
&& x.Elements("city").Any(z => z.Value.Trim() == "Pathankot"));
I'd create an extension to clean it up a bit, and use XPath for the search.
public static class MyXDocumentExtensions
{
public static bool CityExists(this XDocument doc, string cityName)
{
//Contains
//var matchingElements = doc.XPathSelectElements(string.Format("//city[contains(text(), '{0}')]", cityName));
//Equals
var matchingElements = doc.XPathSelectElements(string.Format("//city[text() = '{0}']", cityName));
return matchingElements.Count() > 0;
}
}
And call it like that:
XDocument xmlDocument = XDocument.Load("xml.txt");
var exists = xmlDocument.CityExists("Amritsar");
Expanding on your question in the comment, you can then use it as:
if(!xmlDocument.CityExists("Amritsar"))
{
//insert city
}
If you would like to match regardless of the trailing whitespace in the XML, you can wrap the text() call in XPath with a normalize-space:
var matchingElements = doc.XPathSelectElements(string.Format("//city[normalize-space(text()) = '{0}']", cityName.Trim()));
I am recently working on a .net 2.0 project I have to read some xml files and replace certain elements value.
Wondering how you do it the following not using linq to xml?
IEnumerable<XElement> cities= xmldoc.Descendants("City")
.Where(x => x.Value == "London");
foreach (XElement myElem in cities)
{
myElem.ReplaceWith(new XElement("City", "NewCity"));
}
or
var xElement = xdoc.Descendants("FirstName").Where(x => x.Value == "Max").First();
xElement.ReplaceWith(new XElement("FirstName", "NewValue");
Any suggestions
You can consider using XmlDocument, like this:
string xmlFile = "<xml><data<test /><test /><test /><test /></data></xml>";
var xmlDoc = new XmlDocument();
xmlDoc.Load(xmlFile);
var oNodes = xmlDoc.SelectNodes("//test");
foreach (var oNode in oNodes)
{
oNode.InnerText = "bla bla";
}
xmlDoc.Save("..path to xml file");
(In your case you can use InnerXml property of the document)
http://msdn.microsoft.com/en-us/library/system.xml.xmldocument.aspx
To selectNodes you should pass XPath Query, reference can be found:
http://www.w3schools.com/xpath/
Also if you XML contains namespace, you need to use XmlNamespaceManager:
http://msdn.microsoft.com/en-us/library/system.xml.xmlnamespacemanager.aspx
Otherwise xpath won't work.
You will need to use XmlDocument and query it using XPath with SelectNodes.
It will not be as nice and succint.
I'd like to get all the element name from a xml file, for example the xml file is,
<BookStore>
<BookStoreInfo>
<Address />
<Tel />
<Fax />
<BookStoreInfo>
<Book>
<BookName />
<ISBN />
<PublishDate />
</Book>
<Book>
....
</Book>
</BookStore>
I would like to get the element's name of "BookName". "ISBN" and "PublishDate " and only those names, not include " BookStoreInfo" and its child node's name
I tried several ways, but doesn't work, how can I do it?
Well, with XDocument and LINQ-to-XML:
foreach(var name in doc.Root.DescendantNodes().OfType<XElement>()
.Select(x => x.Name).Distinct())
{
Console.WriteLine(name);
}
There are lots of similar routes, though.
Using XPath
XmlDocument xdoc = new XmlDocument();
xdoc.Load(something);
XmlNodeList list = xdoc.SelectNodes("//BookStore");
gives you a list with all nodes in the document named BookStore
I agree with Adam, the ideal condition is to have a schema that defines the content of xml document. However, sometimes this is not possible. Here is a simple method for iterating all of the nodes of an xml document and using a dictionary to store the unique local names. I like to keep track of the depth of each local name, so I use a list of int to store the depth. Note that the XmlReader is "easy on the memory" since it does not load the entire document as the XmlDocument does. In some instances it makes little difference because the size of the xml data is small. In the following example, an 18.5MB file is read with an XmlReader. Using an XmlDocument to load this data would have been less effecient than using an XmlReader to read and sample its contents.
string documentPath = #"C:\Docs\cim_schema_2.18.1-Final-XMLAll\all_classes.xml";
Dictionary<string, List<int>> nodeTable = new Dictionary<string, List<int>>();
using (XmlReader reader = XmlReader.Create(documentPath))
{
while (!reader.EOF)
{
if (reader.NodeType == XmlNodeType.Element)
{
if (!nodeTable.ContainsKey(reader.LocalName))
{
nodeTable.Add(reader.LocalName, new List<int>(new int[] { reader.Depth }));
}
else if (!nodeTable[reader.LocalName].Contains(reader.Depth))
{
nodeTable[reader.LocalName].Add(reader.Depth);
}
}
reader.Read();
}
}
Console.WriteLine("The node table has {0} items.",nodeTable.Count);
foreach (KeyValuePair<string, List<int>> kv in nodeTable)
{
Console.WriteLine("{0} [{1}]",kv.Key, kv.Value.Count);
for (int i = 0; i < kv.Value.Count; i++)
{
if (i < kv.Value.Count-1)
{
Console.Write("{0}, ", kv.Value[i]);
}
else
{
Console.WriteLine(kv.Value[i]);
}
}
}
The purists way of doing this (and, to be fair, the right way) would be to have a schema contract definition and read it in that way. That being said, you could do something like this...
List<string> nodeNames = new List<string>();
foreach(System.Xml.XmlNode node in doc.SelectNodes("BookStore/Book"))
{
foreach(System.Xml.XmlNode child in node.Children)
{
if(!nodeNames.Contains(child.Name)) nodeNames.Add(child.Name);
}
}
This is, admittedly, a rudimentary method for obtaining the list of distinct node names for the Book node's children, but you didn't specify much else in the way of your environment (if you have 3.5, you could use LINQ to XML to make this a little prettier, for example), but this should get the job done regardless of your environment.
If you're using C# 3.0, you can do the following:
var data = XElement.Load("c:/test.xml"); // change this to reflect location of your xml file
var allElementNames =
(from e in in data.Descendants()
select e.Name).Distinct();
You can try doing it using XPATH.
XmlDocument doc = new XmlDocument();
doc.LoadXml("xml string");
XmlNodeList list = doc.SelectNodes("//BookStore/Book");
If BookStore is ur root element then u can try following code
XmlDocument doc = new XmlDocument();
doc.Load(configPath);
XmlNodeList list = doc.DocumentElement.GetElementsByTagName("Book");
if (list.Count != 0)
{
for (int i = 0; i < list[0].ChildNodes.Count; i++)
{
XmlNode child = list[0].ChildNodes[i];
}
}