Develop Reference

Select a subset of childnodes by name

Given this xml doc
<listOfItem>
<Item id="1">
<attribute1 type="foo"/>
<attribute2 type="bar"/>
<property type="x"/>
<property type="y"/>
<attribute3 type="z"/>
</Item>
<Item>
//... same child nodes
</Item>
//.... other Items
</listOfItems>
Given this xml document, I would like to select, for each "Item" node, just the "property" child nodes. How can I do it in c# directly? With "directly" I mean without selecting all the child nodes of Item and then check one by one. So far:
XmlNodeList nodes = xmldoc.GetElementsByTagName("Item");
foreach(XmlNode node in nodes)
{
doSomething()
foreach(XmlNode child in node.ChildNodes)
{
if(child.Name == "property")
{
doSomethingElse()
}
}
}

You can use SelectNodes(xpath) method instead of ChildNodes property:
foreach(XmlNode child in node.SelectNodes("property"))
{
doSomethingElse()
}
Demo.

Try using LINQ to XML instead of XML DOM as it's much simpler syntax for what you want to do.
XDocument doc = XDocument.Load(filename);
foreach (var itemElement in doc.Element("listOfItems").Elements("Item"))
{
var properties = itemElement.Elements("property").ToList();
}

Formatting an elements text using descendants of XElement

Im wondering how to select a specific element from the heirarchy so that I can format its text.
In the example below I would like to format the specific element to remove the time portion of the date, but I am also looking for a way to format any of the elements for example to add a currency symbol to the text between each price tag.
My example
<orders>
<order>
<type> tools </type> //I would like the ability to select this element
<text> screwdriver </text>
<id> 100981 </id>
<price> 5.00 </price>
<date> 01/01/15 12:51:36 </date>
</order>
<order>
<type> uniform </type>
<text> boots </text>
<id> 100546 </id>
<price> 25.00 </price>
<date> 12/01/15 15:30:41 </date>
</order>
</orders>
What I have so far
foreach (XElement element in doc.Descendants())
{
var nodes = element.Nodes().Where(p => p.NodeType == XmlNodeType.Text);
foreach (XText node in nodes)
{
node.Value = FirstLetterToUpper( node.Value );// set the first letter of each output to be uppercase
}
}
What I have tried
foreach (XElement element in doc.Descendants())
{
var nodes = element.Nodes().Where(p => p.NodeType == XmlNodeType.Text);
if( element.Descendants() == element.Element("date"))
{
element.Value = Convert.ToDateTime(element.Value).ToShortDateString();
}
foreach (XText node in nodes)
{
node.Value = FirstLetterToUpper( node.Value );
}
}
I have some XML experience but have never worked with XElement before.
I've been searching SO for a while now but cant find what Im looking for. The answers below are some of the suggested answers from typing this question but they dont provide a solution as the XML elements are generated dynamically in a loop.
XElement node with text node has its formatting ignored
string.Format in XElement not formatting
Any help with this would be great as I have not attempted this before. Thanks.

You can get the text node's parent using Parent property and check it's name:
foreach (XText node in doc.DescendantNodes()
.Where(x => NodeType == XmlNodeType.Text))
{
if(node.Parent.Name == "date") { ... }
if(node.Parent.Name == "price") { ... }
}
BTW, don't forget the save the document using XDocument.Save method after you made the changes.

I usually create one class to represent the xml and send yo the instance of object with correct type. for Example convert.ToDecimal(node.innerText)

How find element in xdocument and read next elements after them

So i have next xml document:
<Items>
<Item>
<ID>123</ID>
<Name>Super Item</Name>
<Count>1</Count>
<Price>45</Price>
</Item>
<Item>
<ID>456</ID>
<Name>not super Item</Name>
<Count>10</Count>
<Price>5</Price>
</Item>
<Item>
<ID>789</ID>
<Name>Simple Item</Name>
<Count>6</Count>
<Price>10</Price>
</Item>
</Items>
So how can i find needed item by ID and read next values? Thanks in advance.
code:
XDocument doc = XDocument.Load (filePath);
foreach (var item in doc.Descendants("ID"))
{
if ((string)item.Element("ID") == "789")
{
How to read Name "Simple Item"?
How to read Count "6"?
How to read Price "10"?
}
}

By what you are asking you could formatt your xml like this:
<Items>
<Item id="123">
<Name>Super Item</Name>
<Count>1</Count>
<Price>45</Price>
</Item>
<Item id="456">
<Name>not super Item</Name>
<Count>10</Count>
<Price>5</Price>
</Item>
<Item id="789">
<Name>Simple Item</Name>
<Count>6</Count>
<Price>10</Price>
</Item>
</Items>
Then in code:
int yourId = 456;
XDocument doc = XDocument.Load("test.xml");
var result = from el in doc.Root.Elements("Item")
where el.Attribute("id").Value == yourId.ToString()
select el;
The id here is an attribute.And for reading its values 2 ways:
//1º
foreach (var item in result.Elements())
{
Console.WriteLine(item.Name + " = " + item.Value);
}
//2º - will print the element
Console.WriteLine(result);

It depends on what you want to do when you find those values. Here is a general method using a foreach loop to find the item with the specified ID and returning it's name:
private string GetItemName(string _id)
{
XmlDocument xDoc = new XmlDocument();
xDoc.Load("myXmlFile.xml");
foreach (XmlNode item in xDoc.SelectNodes("/Items/Item"))
{
if (item.SelectSingleNode("ID").InnerText == _id)
{
// we found the item! Now what do we do?
return item.SelectSingleNode("Name").InnerText;
}
}
return null;
}

How to correctly perform Linq-to-XML query?

I have a XDocument called currentIndex like that:
<INDEX>
<SUBINDEX>
<!-- Many tag and infos -->
<SUBINDEX>
<ITEM>
<IDITEM>1</IDITEM>
<ITEM>
<ITEM>
<IDITEM>2</IDITEM>
<ITEM>
...
<ITEM>
<IDITEM>n</IDITEM>
<ITEM>
</INDEX>
I would recreate a new XDocument similar to above one:
<INDEX>
<SUBINDEX>
<!-- Many tag and infos -->
<SUBINDEX>
<ITEM>
<IDITEM>2</IDITEM>
<ITEM>
</INDEX>
I want to do this in C#, I have tried starting in this way:
public void ParseItems(XDocument items)
{
IEnumerable<XElement> items = from a in indexGenerale.Descendants(XName.Get("ITEM"))
// where a.Element("IDITEM").Equals("2")
select a;
foreach(var item in items) {
// do something
}
}
Now the problem: If where clause is commented, items contains n elements (one for each ITEM tag), but if I remove that comments items is empty. Why this behaviour. How I need to perform a search?

Use an explicit cast:
from a in indexGenerale.Descendants("ITEM")
where (string)a.Element("IDITEM") == "2"
a.Element("IDITEM") will return an XElement and it will never be equal to "2".Maybe you meant a.Element("IDITEM").Value.Equals("2"), that will also work but explicit cast is safer.It doesn't throw exception if the element wasn't found`,

How to get node by name?

It's a simple task, but I can't make it work. Given the following XML:
<?xml version="1.0" encoding="UTF-8"?>
<product>
<item1></item1>
<item2></item2>
<item3></item3>
</product>
I'd like to get all nodes within product. Following two attempts return no nodes, I don't see why:
XDocument meteoDoc = XDocument.Load("data.xml");
foreach (var item in meteoDoc.Descendants("product")) {//...}
foreach (var item in meteoDoc.Descendants().Where(x => x.Name == "product").Nodes()) {//...}
The following, as expected, would return me all nodes:
foreach (var item in meteoDoc.DescendantNodes()) { //...}
Thx for any tipps, I can't see the problem... :-/

Your first attempt is asking for all the Descendants called product. Your second attempt is finding the direct child nodes of all descendants called product.
It's possible that it's looking for descendants within the root element... if you know that the root element is called product, you could just use:
foreach (var item in meteoDoc.Root.Descendants())
(I can't test your existing code to find out exactly why it's not working for you right now, I'm afraid.)
Note that Descendants will only find descendant elements - if you want all descendant nodes, you need the DescendantNodes method.

Use this:
XDocument meteoDoc = XDocument.Load("data.xml");
foreach (var item in meteoDoc.Root.Descendants())
{
// ...
}

Try this:
foreach (var item in meteoDoc.Descendants("product"))
{
foreach (var prod in item.Descendants())
{
// do something
}
}

I have made a few change to xml, in this way the data is more well-formed and i can give you a piece of code that accomplish your task.
static void Main(string[] args)
{
//Data.xml
/*
<?xml version="1.0" encoding="UTF-8"?>
<product>
<item>
<name>test</name>
</item>
<item>
<name>test2</name>
</item>
<item>
<name>test3</name>
</item>
</product>
*/
XDocument meteoDoc = XDocument.Load("data.xml");
var result = from c in meteoDoc.Descendants("item")
select new { Name = c.Element("name").Value };
foreach (var item in result)
{
Console.WriteLine(item.Name);
}