xsl:message Element (Windows Embedded CE 6.0)
1/6/2010
The <xsl:message> element sends a text message to either the message buffer or a message dialog box, depending on the environment in which the element call is made. It also raises a system-level error message that can be trapped through typical error-handling mechanisms.
Syntax
<xsl:message
terminate = "yes|no" >
</xsl:message>
Attributes
- terminate
The terminate attribute indicates that the XSLT document should stop processing.
Element Information
Number of occurrences |
Unlimited |
Parent elements |
Any element where the content is a template. |
Child elements |
Any element that can occur in a template. |
Remarks
The <xsl:message> element provides a mechanism to debug XSL Transformations (XSLT) style sheets in progress. Whenever an <xsl:message> element is encountered, if the terminate flag is set to "yes" (the default), then the XSLT processor quits, and sends a system-level error message. Expressions contained within the <xsl:message> element evaluate relative to the current context, making message a good way to watch individual elements.
If terminate is set to "no", then the Microsoft XML Parser (MSXML) 3.0 ignores the command. This is a good way to disable error handling without removing it entirely from your Extensible Stylesheet Language (XSL) style sheet, although upcoming implementations can send such messages out to a log file. (This is not currently supported.)
Example
The following sample demonstrates use of the <xsl:message> element.
In the following file, a name is not supplied for the name element in the second record element.
<?xml version="1.0"?>
<?xml-stylesheet href="message.xsl" type="text/xsl"?>
<records>
<record>
<name>Hansen Claus</name>
<address>222 Cherry</address>
<phone>425-555-0102</phone>
</record>
<record>
<name></name>
<address>312 Elm</address>
<phone>425-555-0103</phone>
</record>
</records>
message.xsl
The following style sheet verifies that the name element within a record element has been filled in. If a name field is empty, then a message indicating that the XML is invalid is output.
<xsl:stylesheet xmlns:xsl="http://www.w3.org/1999/XSL/Transform" version="1.0">
<xsl:template match="/">
<xsl:apply-templates select="*"/>
<xsl:copy-of select="."/>
</xsl:template>
<xsl:template match="*">
<xsl:apply-templates select="//record"/>
</xsl:template>
<xsl:template match="record">
<xsl:if test="name=''">
<xsl:message terminate="yes">A name field is empty.
</xsl:message>
</xsl:if>
</xsl:template>
</xsl:stylesheet>
Output
A name field is empty.