XPath: select a node based on another node?

Question

Consider the following XML:

<Items>
    <Item>
        <Code>Test</Code>
        <Value>Test</Value>
    </Item>
    <Item>
        <Code>MyCode</Code>
        <Value>MyValue</Value>
    </Item>
    <Item>
        <Code>AnotherItem</Code>
        <Value>Another value</Value>
    </Item>
</Items>

I would like to select the Value node of the Item that has the Code node in with the value MyCode. How would I go about using XPath?

I've tried using Items/Item[Code=MyCode]/Value but it doesn't seem to work.

Try setting MyCode in astring like this "MyCode", and if it is possible I would recommend using Linq-to-XML. — Yet Another Geek
– Yet Another Geek, Commented Jun 1, 2011 at 15:29
@alexbrn: The bad XML may well be part of the problem, so should be in the answer (in this case). I've addressed it in my answer, for example. I suggest leaving the question how it was asked. — Merlyn Morgan-Graham
– Merlyn Morgan-Graham, Commented Jun 1, 2011 at 15:36
Changed the XML. My XML is a little bit more complex :P. Was just a typo. — Kees C. Bakker
– Kees C. Bakker, Commented Jun 1, 2011 at 15:37
Sorry about that. Please edit again, and I won't "fix" the changes :) Make sure you take care of the Value end tags too - right now they're Code end tags. — Merlyn Morgan-Graham
– Merlyn Morgan-Graham, Commented Jun 1, 2011 at 15:39

Merlyn Morgan-Graham · Accepted Answer · 2011-06-01 15:32:11Z

7

Your XML data is wrong. The Value tag doesn't have correct matching closing tags, and your Item tags don't have matching closing tags (</Item>).

As for your XPath, try enclosing the data you want to match in quotes:

const string xmlString =
@"<Items>
    <Item>
        <Code>Test</Code>
        <Value>Test</Value>
    </Item>
    <Item>
        <Code>MyCode</Code>
        <Value>MyValue</Value>
    </Item>
    <Item>
        <Code>AnotherItem</Code>
        <Value>Another value</Value>
    </Item>
</Items>";

var doc = new XmlDocument();
doc.LoadXml(xmlString);
XmlElement element = (XmlElement)doc.SelectSingleNode("Items/Item[Code='MyCode']/Value");
Console.WriteLine(element.InnerText);

answered Jun 1, 2011 at 15:32

Merlyn Morgan-Graham

59.4k16 gold badges131 silver badges189 bronze badges

Sign up to request clarification or add additional context in comments.

2 Comments

Kees C. Bakker Over a year ago

It seems that the quotes are the issue.

Chris Chilvers Over a year ago

Yes, without the quotes it tries to compare the value of the node Code, to the value of the node MyCode. As expected it doesn't find a node called MyCode.

alexbrn · Accepted Answer · 2011-06-01 15:37:49Z

1

You need:

/Items/Item[Code="MyCode"]/Value

Assuming you fix-up your XML:

<?xml version="1.0"?>
<Items>
  <Item>
    <Code>Test</Code>
    <Value>Test</Value>
  </Item>
  <Item>
    <Code>MyCode</Code>
    <Value>MyValue</Value>
  </Item>
  <Item>
    <Code>AnotherItem</Code>
    <Value>Another value</Value>
  </Item>
</Items>

answered Jun 1, 2011 at 15:37

alexbrn

2,15514 silver badges11 bronze badges

Collectives™ on Stack Overflow

XPath: select a node based on another node?

2 Answers 2

2 Comments

Comments

Your Answer

Linked

Hot Network Questions

Collectives™ on Stack Overflow

2 Answers 2

2 Comments

Comments

Your Answer

Sign up or log in

Post as a guest

Linked

Related