get child nodes xml attribute value - c#

<test>
<acc id="1"> acc1 </acc>
<acc id="2"> acc2 </acc>
<acc id="3"> acc3 </acc>
<acc id="4"> acc4 </acc>
</test>
For example, if I want to take the value of each <acc> element:
var iAccs = xdoc.Descendants("test").Elements("acc").Select(p => p.Value);
List<string> myList = new List<string>();
foreach(string p in iAccs)
{
myList.Add(p);
}
But how to substract all the attribute "id" values of each <acc> elements?

You can easily get this using LINQ-to-XML:-
XDocument xdoc = XDocument.Load(#"You XML file path");
List<string> result = xdoc.Descendants("acc")
.Select(x => (string)x.Attribute("id")).ToList();
Or if you prefer query syntax then:-
List<int> result2 = (from x in xdoc.Descendants("acc")
select (int)x.Attribute("id")).ToList();

Related

How do I find the maximum value of an attribute value in an XML file?

I have an XML file with the following structure:
<doc>
<rootelement>
<childelement id="0" />
<childelement id="1" />
.
.
</rootelement>
</doc>
I want to find the highest numeric value of the id attribute
The idea I have in mind is something like:
int highest = -1;
foreach(var node in xmldoc.SelectNodes("//doc/rootelement/childelement"))
{
highest = Math.Max(GetID(node), highest);
}
where GetID(XMLNode) would retrieve the value of the attribute of the current node.
Is there a more compact (or more efficient) XPath expression to do that?
You can use Linq to Xml:
var xdoc = XDocument.Load(path_to_xml);
var maxId = xdoc.XPathSelectElements("//doc/rootelement/childelement")
.Max(c => (int)c.Attribute("id"));
Or without XPath:
var maxId = xdoc.Root.Elements("rootelement")
.Elements("childelement")
.Max(c => (int)c.Attribute("id"));
With XmlDocument:
var maxId = doc.SelectNodes("//doc/rootelement/childelement")
.Cast<XmlElement>()
.Max(c => Int32.Parse(c.Attributes["id"].Value));
Use Linq to XML.
string xml =
#"<doc>
<rootelement>
<childelement id='0' />
<childelement id='1' />
</rootelement>
</doc>";
var doc = XDocument.Parse(xml);
int max = doc.Descendants("childelement").Max(e => (int)e.Attribute("id"));

Linq to XML... null and missing elements

I have an XML file
<Person>
<PersonItem id="0">
<Time>1/8/2014</Time>
<Step><![CDATA[Normal]]></Step>
<HasAddress/>
<Address/>
</PersonItem>
<PersonItem id="1">
<Time>1/8/2014 3:21:45 PM</Time>
<Step><![CDATA[Normal]]></Step>
<HasAddress/>
<Address/>
</PersonItem>
<PersonItem id="2">
<Time>1/8/2014</Time>
<Step><![CDATA[Normal]]></Step>
<HasAddress>Main</HasAddress>
<Address>
<AddressItem id="0" location=5>
<Address>15 Oak</Address>
</AddressItem>
<AddressItem id="1" location=7>
<Address>12 Maple</Address>
</AddressItem>
<AddressItem id="2" location=8>
<Address>30 Beech</Picture>
</AddressItem>
</Address>
</PersonItem>
</Person>
I want to put to retrieve the information and send some of it to a database. I've tried several different ways of dealing with this and I believe I'm close. Here is the Linq I tried.
public void DoIt(fileName)
{
XElement xml = XElement.Load(fileName);
var items = from item in xml.Elements("PersonItem")
where (from x in item.Elements("HasAddress")
where x.Element("HasAddress") != null
select x).Any()
select item;
Array.ForEach(items.ToArray(),
o=>Console.WriteLine(o.Element("Time").Value));
Console.ReadLine();
}
The problem is nothing is being returned.
Could be just a typo but in your xml file there is this tag error.
<Address>30 Beech</Picture>
which should be:
<Address>30 Beech</Address>
Try this:
XElement xml = XElement.Load(fileName);
var items = xml.Descendants("PersonItem")
.Where(x => (string)x.Element("HasAddress") != null)
.Select(x => x);
XDocument xml = XDocument.Load("Input.xml");
var items = from item in xml.Root.Elements("PersonItem")
where !string.IsNullOrEmpty((string)item.Element("HasAddress"))
select item;
For your sample XML document returns only the last PersonItem element.

List is empty after parsing XML with LinQ

I have an xml file similar to the following:
<doc>
<file>
<header>
<source>
RNG
</source>
</header>
<body>
<item name="items.names.id1">
<property>propertyvalue1</property>
</item>
<!-- etc -->
<item name="items.names.id100">
<property>propertyvalue100</property>
</item>
<!-- etc -->
<item name="otheritems.names.id100">
<property>propertyvalue100</property>
</item>
</body>
</file>
</doc>
And the following class:
private class Item
{
public string Id;
public string Property;
}
The file has, for example, 100 item entries (labeled 1 to 100 in the name attribute). How can I use Linq Xml to get hold of these nodes and place them a in list of item?
Using Selman22's example, I'm doing the following:
var myList = xDoc.Descendants("item")
.Where(x => x.Attributes("name").ToString().StartsWith("items.names.id"))
.Select(item => new Item
{
Id = (string)item.Attribute("name"),
Name = (string)item.Element("property")
}).ToList();
However, the list is empty. What am I missing here?
Using LINQ to XML:
XDocument xDoc = XDocument.Load(filepath);
var myList = xDoc.Descendants("item").Select(item => new Item {
Id = (string)item.Attribute("name"),
Property = (string)item.Element("property")
}).ToList();
You can use LinqToXml to directly query the XML, or deserialize it and use LINQ to object. If you choose to deserialize I suggest to start from the schema and generate the classes representing your datamodel with xsd.exe. If you don't have the schema of your xml, even xsd.exe can infer one from an example xml file, but you probably need to fine tune the result.
Try this one XElement root = XElement.Parse("your file name");
var items textSegs =(from item in root.Descendants("item")
select item).ToList();
Now iterate over list and store it
The below is a way of getting information from xml using Xdocument.
string input = "<Your xml>";
Xdocument doc = XDocument.Parse(input);
var data = doc.Descendants("item");
List<Items> itemsList = new List<Items>();
foreach(var item in data)
{
string itemname= item.Element("item").Value;
string property = item.Element("property").Value;
itemsList.Add(new item(itemname, property));
}
I'm guessing you want the code given how your question is phrased.. also I'm assuming the real XML is very simplistic as well.
var items = from item in doc.Descendants("item")
select new Item()
{
Id = item.Attributes("name").First().Value,
Property = item.Elements().First().Value,
};
Just ensure that your xml is loaded into doc. You can load the xml in two ways:
// By a string with xml
var doc = XDocument.Parse(aStringWithXml);
// or by loading from uri (file)
var doc = XDocuemnt.Load(aStringWhichIsAFile);

Get the Value of XElements that dont has Child

How can I get the value of a Node in a XDocument when don't has more childs ?
<Contacts>
<Company>
<Name>Testing</Name>
<ID>123</ID>
</Company>
</Contacts>
In this case, I wanna get the value of the <Name> and <ID> element, because don't has child elements in them.
I'm trying the follow
protected void LeXMLNode(HttpPostedFile file)
{
XmlReader rdr = XmlReader.Create(file.FileName);
XDocument doc2 = XDocument.Load(rdr);
foreach (var name in doc2.Root.DescendantNodes().OfType<XElement>().Select(x => x.Name).Distinct())
{
XElement Contact = (from xml2 in doc2.Descendants(name.ToString())
where xml2.Descendants(name.ToString()).Count() == 0
select xml2).FirstOrDefault();
string nome = name.ToString();
}
}
but without success, because my foreach pass in all Elements and I wanna get just the value of Elements that don't has childs.
document.Root.Elements("Company").Elements()
.Where(item => !item.HasElements).ToList();
See XElement.HasElements: http://msdn.microsoft.com/en-us/library/system.xml.linq.xelement.haselements.aspx

Filter XDocument more efficiently

I would like to filter with high performance XML elements from an XML document.
Take for instance this XML file with contacts:
<?xml version="1.0" encoding="ISO-8859-1"?>
<?xml-stylesheet type="text/xsl" href="asistentes.xslt"?>
<contactlist evento="Cena Navidad 2010" empresa="company">
<contact type="1" id="1">
<name>Name1</name>
<email>xxxx#zzzz.es</email>
<confirmado>SI</confirmado>
</contact>
<contact type="1" id="2">
<name>Name2</name>
<email>xxxxxxxxx#zzzze.es</email>
<confirmado>Sin confirmar</confirmado>
</contact>
</contaclist>
My current code to filter from this XML document:
using System;
using System.Xml.Linq;
class Test
{
static void Main()
{
string xml = #" the xml above";
XDocument doc = XDocument.Parse(xml);
foreach (XElement element in doc.Descendants("contact")) {
Console.WriteLine(element);
var id = element.Attribute("id").Value;
var valor = element.Descendants("confirmado").ToList()[0].Value;
var email = element.Descendants("email").ToList()[0].Value;
var name = element.Descendants("name").ToList()[0].Value;
if (valor.ToString() == "SI") { }
}
}
}
What would be the best way to optimize this code to filter on <confirmado> element content?
var doc = XDocument.Parse(xml);
var query = from contact in doc.Root.Elements("contact")
let confirmado = (string)contact.Element("confirmado")
where confirmado == "SI"
select new
{
Id = (int)contact.Attribute("id"),
Name = (string)contact.Element("name"),
Email = (string)contact.Element("email"),
Valor = confirmado
};
foreach (var contact in query)
{
...
}
Points of interest:
doc.Root.Elements("contact") selects only the <contact> elements in the document root, instead of searching the whole document for <contact> elements.
The XElement.Element method returns the first child element with the given name. No need to convert the child elements to a list and take the first element.
The XElement and XAttribute classes provide a wide selection of convenient conversion operators.
You could use LINQ:
foreach (XElement element in doc.Descendants("contact").Where(c => c.Element("confirmado").Value == "SI"))

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