Xpath to generate an xpath string to the current item

An xpath to be used in either xquery or XSLT to generate the heirarchical path to the current item

string-join(
   (for $node in ancestor::* 
    return 
      concat($node/name(),
              '[', 
              count($node/preceding-sibling::*[name() = $node/name()])+1, 
              ']'
            ),
      concat(name(),
              '[', 
              count(preceding-sibling::*[name() = current()/name()]) + 1, 
              ']'
            )
    ),
  '/')

Find Duplicate IDs with XSLT

This little snippet of XSLT is a useful tool to find all duplicate ids within an XML source document and generate a report with the count of duplicates and xpath to each element that has a duplciate id attribute.

This relies upon the attribute in question being names @id but it is simple enough to change this to whatever attribute you need to interrogate

Note that this is XSLT 2 and has been used with the Saxon transformation engine

<xsl:stylesheet version="2.0" 
  xmlns:xsl="http://www.w3.org/1999/XSL/Transform"
  xmlns:xs="http://www.w3.org/2001/XMLSchema"
 
  exclude-result-prefixes="xs">

  <xsl:output indent="yes"/>
  
  <xsl:key name="ids" match="*[@id]" use="@id"/> 

  <xsl:template match="/">
    <duplicates>
      <xsl:apply-templates select="//*[@id]"/>
    </duplicates>
  </xsl:template>


  <xsl:template match="*[@id]">
    <xsl:if test="count(key('ids', @id)) &gt; 1">
      <duplicate 
        id="{@id}" 
        dup-count="{count(key('ids', @id))}" 
        node-xpath="{string-join((for $node in ancestor::* return concat($node/name(),'[', count($node/preceding-sibling::*[name() = $node/name()])+1, ']'),concat(name(),'[', count(preceding-sibling::*[name() = current()/name()]) + 1, ']')
   ),'/')}">
     
      </duplicate>
    </xsl:if>
  </xsl:template>

</xsl:stylesheet>

Xsparql - a first attempt!

Xsparql is an easy method of using sparql queries with an xquery syntax. I thought I would give this a go with a data scrape from the schema.org markup on my own walks blog. The specific page I chose was The South West Coast Path - Marazion to Porthleven walk. I wasnt going to do anything complicated, just attempt to pull out the co-ordinates and names of the places featured in the walk posting.

First I needed an implementation of the xsparql specification, this I found at http://xsparql.deri.org/.

Then I needed an rdf source, this was created by scraping my blog posting mentioned above using Apache Any23 - Anything To Triples - Live Service Demo and requesting xml/rdf output which was saved as any23.org.rdf.

The xsparql code was then put together - it seemed to be white space sensitive in some instances and took a few attempts to get working. The code below was used and saved to a file named query.xs:

declare namespace place = "http://schema.org/Place/";
declare namespace geo = "http://schema.org/GeoCoordinates/";

<places>
{ for $Place $Name from <any23.org.rdf>
  where { $Place place:name $Name }
  order by $Name
  return <place obj="{$Place}" name="{$Name}" >
         { for $Name $Geo $lat $long from <any23.org.rdf>
           where { $Place place:geo  $Geo.
   $Place place:name $Name.
   $Geo geo:latitude $lat.
   $Geo geo:longitude $long}
           return <geo> 
   <lat>{ $lat }</lat>
   <long>{$long}</long>
  </geo>
         }
</place>
}
</places>

The implementation was then invoked with the following command line:

java -jar cli-0.5-jar-with-dependencies.jar query.xs -f result.xml

Which generateed the result document:

<places>
   <place name="Marazion" obj="b0">
      <geo>
         <lat>50.118267</lat>
         <long>-5.4776716</long>
      </geo>
   </place>
   <place name="Porthleven" obj="b1">
      <geo>
         <lat>50.118267</lat>
         <long>-5.4776716</long>
      </geo>
   </place>
   <place name="Prussia Cove Smugglers" obj="b2">
      <geo>
         <lat>50.101272</lat>
         <long>-5.4157501</long>
      </geo>
   </place>
   <place name="St Michael's Mount" obj="b3">
      <geo>
         <lat>50.116836</lat>
         <long>-5.4779291</long>
      </geo>
   </place>
</places>

Funky stuff!