Want to skip a tag and get by index

Question

Given this XML:

<mets:mets>
 <mets:fileSec>
   <mets:fileGrp ID="fileGrp001" USE="image/dynamic">
  <mets:file ID="filebib4112678_18760203_1_24_0001_m.jp2" MIMETYPE="image/jp2" SIZE="5308416"
    CREATED="2009-11-10T00:00:00" USE="image/dynamic" ADMID="techMD001"
    CHECKSUM="c07f516d77d8a5ca452775d489ffe78c" CHECKSUMTYPE="MD5">
    <mets:FLocat LOCTYPE="URL" xlink:type="simple"
      xlink:href="file:bib4112678_18760203_1_24_0001_m.jp2"/>
  </mets:file>
  <mets:file ID="filebib4112678_18760203_1_24_0002_m.jp2" MIMETYPE="image/jp2" SIZE="5308416"
    CREATED="2009-11-10T00:00:00" USE="image/dynamic" ADMID="techMD002"
    CHECKSUM="6497ceb7a8477fbe9ba4ff9e6e57999f" CHECKSUMTYPE="MD5">
    <mets:FLocat LOCTYPE="URL" xlink:type="simple"
      xlink:href="file:bib4112678_18760203_1_24_0002_m.jp2"/>
  </mets:file>

</mets:fileGrp>
<mets:fileGrp ID="fileGrp002" USE="text/alto">
  <mets:file ID="filebib4112678_18760203_1_24_0001_alto.xml" MIMETYPE="text/xml" SIZE="1114112"
    CREATED="2009-11-10T00:00:00" USE="text/alto" ADMID="techMD005"
    CHECKSUM="e391852693f78d2eb024caf6dbdb97c6" CHECKSUMTYPE="MD5">
    <mets:FLocat LOCTYPE="URL" xlink:type="simple"
      xlink:href="file:bib4112678_18760203_1_24_0001_alto.xml"/>
  </mets:file>
  <mets:file ID="filebib4112678_18760203_1_24_0002_alto.xml" MIMETYPE="text/xml" SIZE="1114112"
    CREATED="2009-11-10T00:00:00" USE="text/alto" ADMID="techMD006"
    CHECKSUM="e391852693f78d2eb024caf6dbdb97c6" CHECKSUMTYPE="MD5">
    <mets:FLocat LOCTYPE="URL" xlink:type="simple"
      xlink:href="file:bib4112678_18760203_1_24_0002_alto.xml"/>
  </mets:file>

   </mets:fileGrp>
  </mets:fileSec>
</mets:mets>

This expression :

/mets/fileSec/fileGrp[2]/file[2]/@ADMID

gives the result "techMD006"

However, I would like to get the same result using something like this expression/query:

/mets/fileSec//file[4]/@ADMID

I.e I don't want to bother about the fileGrp element, since it makes things more complicated. Unfortunately the expression above didn't work..

Does anyone know how to make such an expression?

thanx!

Check this out, I think you'll be able to query for your file element and then just select the index you want...http://stackoverflow.com/questions/4007413/xpath-query-to-get-nth-instance-of-an-element — Sam Trost, Mar 25 '11 at 15:47
One of the many duplicates of this FAQ: http://stackoverflow.com/questions/4007413/xpath-query-to-get-nth-instance-of-an-element — , Mar 26 '11 at 01:00

score 1 · Accepted Answer · answered Mar 25 '11 at 16:03

Your expression retrieves all file elements that are a descendant of /mets/fileSec and are the fourth child of their parent:

/mets/fileSec//file[4]/@ADMID

But you have no such elements. What you want is to retrieve all file elements that are a descendant of /mets/fileSec and then take the fourth one. Use this:

(/mets/fileSec//file)[4]/@ADMID

Want to skip a tag and get by index

1 Answers1