XSLT for recursive XML element-CodePudding

I am working on an XML standard for swimming programs. I created an XML schema and some example XML files. Since swimming programs often use repetitions (e.g. 4 x 100m Freestyle), I created an XML element <instruction> that can include further instances of itself. It uses the <XS:choice> to either include a <repetition> (e.g 4 x) or direct swimming instructions (100m Freestyle). A <repetition> can then include further repetitions and/or direct swimming instructions.

I am now trying to use XSLT to convert instance1.xml to something like goal.xhtml. While I was able to get the basic XSLT transformation going (e.g. <author>), I am struggling with the recursive nature of the XML Schema and the <instruction>' element. I just can't get my head around how to even start with a solution.

Is there anybody out there who could maybe have a look at the XML file examples and suggest a strategy for the XSLT transformation?

CodePudding user response：

The general strategy in XSLT for dealing with recursive XML structures (i.e. elements which can contain other elements of the same type) is to use template matching. You would create a template which matches the element concerned (e.g. <xsl:template match="instruction">); the template then produces some output, and also uses xsl:apply-templates to process child elements, which (assuming there are child elements of the same type) is effectively a recursive call to the same template.

CodePudding user response：

Reinforcing @ConalTuohy's answer, the standard design pattern for XSLT stylesheets handles recursion without you even needing to think about it. Ask yourself "what do I need to do when I encounter an instruction element?", and the answer will probably be something like "generate a ul element with li elements for its children.". So write a template rule something like

<xsl:template match="instruction">
 <ul>
   <xsl:for-each select"child::node()">
     <li><xsl:apply-templates select="."/></li.
   </xsl:for-each>
 </ul>
</xsl:template>

Note: this answer relates to the general question of "how do I get started". I haven't studied your input and output in any detail.