xpathxpath-3.1

XPath sorting not persistent?

I have a following XML:

<doc>
<ActivityNarrativeInformation>
  <ActivityID>123456789</ActivityID>
  <ActivityNarrativeInformationID>111111111</ActivityNarrativeInformationID>
  <ActivityNarrativeSequenceNumber>1</ActivityNarrativeSequenceNumber>
  <ActivityNarrativeText>She Sells Sea Shells by the Sea Shore and she also</ActivityNarrativeText>
  </ActivityNarrativeInformation>
 <ActivityNarrativeInformation>
  <ActivityID>123456789</ActivityID>
  <ActivityNarrativeInformationID>111111111</ActivityNarrativeInformationID>
  <ActivityNarrativeSequenceNumber>3</ActivityNarrativeSequenceNumber>
  <ActivityNarrativeText>triple shot frappuccino, extra hot, with whipped cream in a tall cup </ActivityNarrativeText>
</ActivityNarrativeInformation>
<ActivityNarrativeInformation>
  <ActivityID>123456789</ActivityID>
  <ActivityNarrativeInformationID>111111111</ActivityNarrativeInformationID>
  <ActivityNarrativeSequenceNumber>2</ActivityNarrativeSequenceNumber>
  <ActivityNarrativeText>likes to take long walks on the beach while she drinks a</ActivityNarrativeText>
  </ActivityNarrativeInformation>
<ActivityNarrativeInformation>
  <ActivityID>987654321</ActivityID>
  <ActivityNarrativeInformationID>222222222</ActivityNarrativeInformationID>
  <ActivityNarrativeSequenceNumber>486</ActivityNarrativeSequenceNumber>
  <ActivityNarrativeText>It was a dark and stormy night; the rain fell in torrents--except at occasional intervals, when
 </ActivityNarrativeText>
</ActivityNarrativeInformation>
<ActivityNarrativeInformation>
  <ActivityID>987654321</ActivityID>
  <ActivityNarrativeInformationID>222222222</ActivityNarrativeInformationID>
  <ActivityNarrativeSequenceNumber>488</ActivityNarrativeSequenceNumber>
  <ActivityNarrativeText>scene lies), rattling along the housetops, and fiercely agitating the scanty flame of the lamps that
</ActivityNarrativeText>
</ActivityNarrativeInformation>
<ActivityNarrativeInformation>
  <ActivityID>987654321</ActivityID>
  <ActivityNarrativeInformationID>222222222</ActivityNarrativeInformationID>
  <ActivityNarrativeSequenceNumber>487</ActivityNarrativeSequenceNumber>
  <ActivityNarrativeText>was checked by a violent gust of wind which swept up the streets (for it is in London that our
</ActivityNarrativeText>
</ActivityNarrativeInformation>
<ActivityNarrativeInformation>
  <ActivityID>987654321</ActivityID>
  <ActivityNarrativeInformationID>222222222</ActivityNarrativeInformationID>
  <ActivityNarrativeSequenceNumber>489</ActivityNarrativeSequenceNumber>
  <ActivityNarrativeText>struggled against the darkness.
</ActivityNarrativeText>
</ActivityNarrativeInformation>
<ActivityNarrativeInformation>
  <ActivityID>55555555</ActivityID>
  <ActivityNarrativeInformationID>77777777</ActivityNarrativeInformationID>
  <ActivityNarrativeSequenceNumber>31921</ActivityNarrativeSequenceNumber>
  <ActivityNarrativeText>Papa Bear was very big and growly. Mamma Bear was middle-sized and pleasant.
</ActivityNarrativeText>
</ActivityNarrativeInformation>
<ActivityNarrativeInformation>
  <ActivityID>55555555</ActivityID>
  <ActivityNarrativeInformationID>77777777</ActivityNarrativeInformationID>
  <ActivityNarrativeSequenceNumber>31923</ActivityNarrativeSequenceNumber>
  <ActivityNarrativeText>Papa bear loved to fix things around the house; Mama bear loved to grow flowers in her garden; and, Baby bear loved playing in the yard. They were very happy. </ActivityNarrativeText>
</ActivityNarrativeInformation>
<ActivityNarrativeInformation>
  <ActivityID>55555555</ActivityID>
  <ActivityNarrativeInformationID>77777777</ActivityNarrativeInformationID>
  <ActivityNarrativeSequenceNumber>31920</ActivityNarrativeSequenceNumber>
  <ActivityNarrativeText>Once upon a time there were three bears, Papa Bear, Mamma Bear and Baby Bear
</ActivityNarrativeText>
</ActivityNarrativeInformation>
<ActivityNarrativeInformation>
  <ActivityID>55555555</ActivityID>
  <ActivityNarrativeInformationID>77777777</ActivityNarrativeInformationID>
  <ActivityNarrativeSequenceNumber>31922</ActivityNarrativeSequenceNumber>
  <ActivityNarrativeText>And Baby Bear, well, he was small, and
sometimes he squeaked! They lived in a pretty little house on the edge of the forest
</ActivityNarrativeText>
</ActivityNarrativeInformation>
</doc

I need to group ActivityNarrativeInformation elements by ActivityID and concatenate ActivityNarrativeText in such a way, that it is sorted by ActivityNarrativeSequenceNumber

I managed to sort elements with following XPath query (XPath 3.1) sort(//ActivityNarrativeInformation[ActivityID=123456789], (), function($ActivityNarrativeSequenceNumber) {$ActivityNarrativeSequenceNumber})

So the result looks like this:

<ActivityNarrativeInformation>
  <ActivityID>123456789</ActivityID>
  <ActivityNarrativeInformationID>111111111</ActivityNarrativeInformationID>
  <ActivityNarrativeSequenceNumber>1</ActivityNarrativeSequenceNumber>
  <ActivityNarrativeText>She Sells Sea Shells by the Sea Shore and she also</ActivityNarrativeText>
  </ActivityNarrativeInformation>
<ActivityNarrativeInformation>
  <ActivityID>123456789</ActivityID>
  <ActivityNarrativeInformationID>111111111</ActivityNarrativeInformationID>
  <ActivityNarrativeSequenceNumber>2</ActivityNarrativeSequenceNumber>
  <ActivityNarrativeText>likes to take long walks on the beach while she drinks a</ActivityNarrativeText>
  </ActivityNarrativeInformation>
<ActivityNarrativeInformation>
  <ActivityID>123456789</ActivityID>
  <ActivityNarrativeInformationID>111111111</ActivityNarrativeInformationID>
  <ActivityNarrativeSequenceNumber>3</ActivityNarrativeSequenceNumber>
  <ActivityNarrativeText>triple shot frappuccino, extra hot, with whipped cream in a tall cup </ActivityNarrativeText>
</ActivityNarrativeInformation>

The probelm however is, that if I want to limit down above to just all ActivityNarrativeText by adding /ActivityNarrativeText at the end like this

sort(//ActivityNarrativeInformation[ActivityID=123456789], (), function($ActivityNarrativeSequenceNumber) {$ActivityNarrativeSequenceNumber})/ActivityNarrativeText

or

sort(//ActivityNarrativeInformation[ActivityID=123456789]/ActivityNarrativeText, (), function($seq) {$seq/ActivityNarrativeSequenceNumber})

The order is lost:

<ActivityNarrativeText>She Sells Sea Shells by the Sea Shore and she also</ActivityNarrativeText>
<ActivityNarrativeText>triple shot frappuccino, extra hot, with whipped cream in a tall cup </ActivityNarrativeText>
<ActivityNarrativeText>likes to take long walks on the beach while she drinks a</ActivityNarrativeText>

What am I doing wrong?

Solution

  • In addition to the right answer not to use / after sorting but ! instead, one of your attempts would actually work if your sort function argument selected the right element as the sort key:

    sort(//ActivityNarrativeInformation[ActivityID=123456789]/ActivityNarrativeText, (), function($text) {$text/../ActivityNarrativeSequenceNumber})