[xsl] FW: Stopping recursion

["Mark Seaborne" <mseaborne@xxxxxxxxxxxxxxxxx>]

Hi,

I have a 1.0 stylesheet that takes a WXS schema and adds xml:base to certain
complex type definitions. The rule for inclusion of the attribute is that
the complex type must either include directly, or have a descendent in
another complex type that includes the XLink namespace.

So the stylesheet recurses through each complex type and tests to see if
they contain anything belonging to the XLink namespace. If the type is
itself a complex type the template is called again to check to see if that
one has any elements within the XLink namespace, and so on. If the XLink
namespace is found then <xsd:attribute ref="xml:base"/> is output.

My problem is that once the XLink namespace is found I would like the
recursion to stop, mainly because if the namespace is found in more than one
descendent element/attribute declaration the attribute is added multiple
times.

I suspect that either my approach is totally wrong, or this is a common
enough problem that there is a design pattern I can use to achieve the
effect I want, but I haven't hit on the key words to find it. So any
pointers would be gratefully received.

This is the template causing the problem:

<xsl:template match="xsd:element" mode="findXLink">
   <xsl:choose>
   <!-- if the element is declared locally (has a type attribute_ -->
      <xsl:when test="@type">
        <!-- remove the namespace prefix from the qname -->
        <xsl:variable name="myType" select="substring-after(@type, ':')"/>
        <xsl:for-each select="/xsd:schema/xsd:complexType[@name = $myType]">
        <xsl:choose>
        <!-- if the complex type definition includes anything in the XLink
namespace output the xml:base attribute -->
          <xsl:when test=".//@namespace='http://www.w3.org/1999/xlink'">
            <xsd:attribute ref="xml:base"/>
          </xsl:when>
       <!-- otherwise apply this template to all of the elements declared
within the complex type -->
          <xsl:otherwise>
             <xsl:apply-templates select=".//xsd:element" mode="findXLink"/>
          </xsl:otherwise>
        </xsl:choose>
      </xsl:for-each>
    </xsl:when>
    <!-- otherwise assume that the element references a globally declared
element, so look for that -->
    <xsl:otherwise>
      <xsl:variable name="myName" select="substring-after(@ref, ':')"/>
      <xsl:apply-templates select="//xsd:element[@name = $myName]"
mode="findXLink"/>
     </xsl:otherwise>
   </xsl:choose>
</xsl:template>

All the best

Mark
The information in this e-mail is sent in confidence for the addressee only
and may be legally privileged. Unauthorised recipients must preserve this
confidentiality and should please advise the sender immediately of the error
in transmission and then delete this e-mail. If you are not the intended
recipient, any disclosure, copying, distribution or any action taken in
reliance on its content is prohibited and may be unlawful.

Origo Services Limited accepts no responsibility for any loss or damage
resulting directly or indirectly from the use of this e-mail or the contents.
It is your responsibility to scan for viruses.  Origo Services Limited
reserves the right to monitor e-mails sent to or from addresses under its
control.  When you reply to this e-mail, you are consenting to Origo Services
Limited monitoring the content of the e-mails you send to or receive from
Origo Services Limited.  If this e-mail is non-business related Origo Services
Limited is not liable for any opinions expressed by the sender.  The contents
of this e-mail are protected by copyright.  All rights reserved.



Origo Services Limited is a company incorporated in Scotland (company number
115061) having its registered office at 4th floor, Saltire Court, 20 Castle
Terrace, Edinburgh EH1 2EN.