help needed in writing xpath

anboss · November 14th, 2008, 12:55 PM

The input to my xsl is the following xml:

<root>
<message>
<messageId>BPL34</messageId>
<timeStamp>2008-11-14T16:47:24.881</timeStamp>
<description>description for 34 goes here</description>
</message>
<message>
<messageId>BPL92</messageId>
<timeStamp>2008-11-14T16:47:24.883</timeStamp>
<description>description for 92 goes here</description>
</message>
</root>

The input xml contains two message tags. I need to get the description tag value for the messageId BPL34 and my output xml shd be:

<root>
<result>
<description>description for 34 goes here</description>
</result>
</root>

can anyone help me with the xpath expression which i shd use here inorder to get the description tag alone from the input xml?

iceandrews · November 14th, 2008, 01:02 PM

If your document structure is the same. You can use:
/message/messageId[. = 'BPL34']/description

This will select the description node that is a child of messageId, that is a child of message, that stems from the root.

If you want ALL the description nodes, regardless of their location within, use:
//description[.. = 'BPL34']

By the way this is pretty basic stuff that you need if you're going to learn XSLT at all. I would recommend picking up a book, or possibly reading the http://www.w3schools.com/ guides for starters.

Martin Honnen · November 14th, 2008, 01:04 PM

XPath alone does not suffice to transform the XML, you need XSLT to do that:

Code:

<xsl:stylesheet
  xmlns:xsl="http://www.w3.org/1999/XSL/Transform"
  version="1.0">

  <xsl:param name="msgId" select="'BPL34'"/>


  <xsl:template match="root">
    <xsl:copy>
      <result>
        <xsl:copy-of select="message[messageId = $msgId]/description"/>
      </result>
    </xsl:copy>
  </xsl:template>

</xsl:stylesheet>

--
Martin Honnen
Microsoft MVP - XML

anboss · November 14th, 2008, 01:07 PM

Thanks Martin for the response.

My requirement is slightly different. The message tag will be in any order. So, is there a way to get the description tag only when the messageId is BPL34?

anboss · November 14th, 2008, 01:10 PM

Thanks for the response..

Martin Honnen · November 14th, 2008, 01:21 PM

Quote:

quote:Originally posted by anboss
Thanks Martin for the response.

My requirement is slightly different. The message tag will be in any order. So, is there a way to get the description tag only when the messageId is BPL34?

My posted stylesheet, when applied to the XML input you posted, produces the described result.
If your requirement is different now, meaning your XML input and/or your needed result is different, then you need to describe the new XML input and/or the new result you want.

--
Martin Honnen
Microsoft MVP - XML

anboss · November 14th, 2008, 01:26 PM

I overlooked the xsl that you have posted. Thanks Martin for the response. Requirement accomplished.