Question

I’ve seen some variations of this quesiton asked here, but I’m not sure how to apply them to my situation, so I’m hoping maybe someone can help me here.

I have a flat XML file in a format similar to this one:

<item id="1"/>
<item id="1.1"/>
<item id="1.1.1"/>
<item id="1.1.2"/>
<item id="1.1.2.1"/>
<item id="1.2"/>
<item id="1.3"/>

I’m looking to set up the tags hierarchically based on the id attribute, like so:

<item id="1">
  <item id="1.1">
    <item id="1.1.1"/>
    <item id="1.1.2">
      <item id="1.1.2.1"/>
    </item>
  </item>
  <item id="1.2"/>
  <item id="1.3"/>
</item>

Some of the id values have two digit numbers (e.g., “1.2.3.15.1”) which makes comparing them even more challenging.

Help?

Answer 1

Selecting the correct nodes can be tricky but as you have no hierarchy this works for your sample input (if you add a root element to it)

  <!-- start somewhere -->
  <xsl:template match="/root">
    <root>
      <!-- select all with no . in the id -->
      <xsl:apply-templates  select="//item[string-length(translate(@id,'1234567890',''))=0]" />
    </root>
  </xsl:template>

  <xsl:template match="item">
    <xsl:variable name="id" select="@id"/>
    <!-- how many . have we ? That is how deep we are and add 1 -->
    <xsl:variable name="deep" select="string-length(translate(@id,'1234567890',''))+1" />
    <xsl:copy>
      <!-- copy attribs over -->
      <xsl:apply-templates select="@*"/> 
      <!-- select all nodes that start with our curent id,  
           select nodes that are just one level below us 
           and don't select our selfs-->
      <xsl:apply-templates select="//item[starts-with(@id, $id) and string-length(translate(@id,'1234567890',''))=$deep and not(@id=$id)]"/>
    </xsl:copy>
  </xsl:template>

  <!-- copy attribs -->
  <xsl:template match="@*">
    <xsl:copy />
  </xsl:template>