CODEWITHSUNDEEP
javaxmlxslt
Abin Manathoor Devasia
Abin Manathoor Devasia

Reputation: 1973

How can I throw an exception from XSLT?

I want to throw an exception if one tag doesn't contain an attribute.

Upvotes: 32

Views: 20198

Answers (3)

Petr Kozelka
Petr Kozelka

Reputation: 7980

Use xsl:message with terminate="yes" to achieve effect similar to throwing an exception:

<xsl:if test="(your condition)">
   <xsl:message terminate="yes">ERROR: Missing attribute XYZ under
      <xsl:value-of select="local-name()"/> !</xsl:message>
</xsl:if>

This causes the message to be sent to STDERR and terminate processing.

BTW. this is heavily used in Schematron validation.

Upvotes: 37

Dimitre Novatchev
Dimitre Novatchev

Reputation: 243449

In addition to the correct answer of using <xsl:message terminate="yes"/>:

  1. In XSLT 3.0 one can use the new instructions <xsl:try ...> and <xsl:catch ...>: http://www.w3.org/TR/xslt-30/#try-catch

  2. In XSLT 2.0 one can also use the standart XPath function error() to terminate the processing.

Here is an example of using xsl:try and xsl:catch:

<xsl:result-document href="out.xml">
  <xsl:variable name="result">
    <xsl:call-template name="construct-output"/>
  </xsl:variable>
  <xsl:try>
    <xsl:copy-of select="$result" validation="strict"/>
    <xsl:catch>
      <xsl:message>Warning: validation of result document failed:
          Error code: <xsl:value-of select="$err:code"/>
          Reason: <xsl:value-of select="$err:description"/>
      </xsl:message>
      <xsl:sequence select="$result"/>
    </xsl:catch>
  </xsl:try>
</xsl:result-document>

Upvotes: 26

Rookie Programmer Aravind
Rookie Programmer Aravind

Reputation: 12154

XSLT isn't meant for validation! it is meant for transformation .. (well XSLT stands for EXtensible Stylesheet Language Transformation)

If you want to validate hierarchy (that is your requirement) and validate the data .. then go for XSD! Extensible Schema Definition..

here is a link reference to learn XSD

XML has to be validated against the XSD by the host code (C#, Java etc) The validation returns set of results. Success or fail with validation errors (if exist)..

Upvotes: 2

Related Questions