from javax.xml.parsers import ParserConfigurationException
from javax.xml.parsers import DocumentBuilderFactory
from javax.xml.xpath import XPath
from javax.xml.xpath import XPathExpressionException
from javax.xml.xpath import XPathFactory
from javax.xml.xpath import XPathConstants
from org.xml.sax import InputSource
from org.virbo.dataset import DDataSet

from java.io import File
from java.io import FileInputStream

import java

ss= PWD + '20100305_1600.xml'  

file= getFile( ss, monitor )  # from http://forecast.weather.gov/

myin= FileInputStream( file )

builder = DocumentBuilderFactory.newInstance().newDocumentBuilder()
source = InputSource( myin )
initialDocument = builder.parse(source)

factory= XPathFactory.newInstance()
xpath= factory.newXPath()

# // is anywhere, / is root.
temps= xpath.evaluate( '/dwml/data/parameters/temperature[@type="hourly"]/value', initialDocument, XPathConstants.NODESET )
ttemps= DDataSet.createRank1( temps.getLength() )
for i in range( temps.getLength() ):
   value = xpath.evaluate('text()', temps.item(i), XPathConstants.STRING)
   if value:
      ttemps.putValue( i, java.lang.Integer.parseInt( value ) )
   else:
      ttemps.putValue( i, -1e31 )
ttemps.putProperty( QDataSet.FILL_VALUE, -1e31 )

times= xpath.evaluate( '/dwml/data/time-layout/start-valid-time/text()', initialDocument, XPathConstants.NODESET )

ttimes= DDataSet.createRank1( times.getLength() )

tp= TimeParser.create( TimeParser.iso8601String( times.item(0).nodeValue[0:19]) )
tp.parse( times.item(0).nodeValue[0:19] ).getTime( Units.us2000 )

for i in range( times.getLength() ):
   ttimes.putValue( i, tp.parse( times.item(i).nodeValue[0:19] ).getTime( Units.us2000 ) )
ttimes.putProperty( QDataSet.UNITS, Units.us2000 )

ttemps.putProperty( QDataSet.DEPEND_0, ttimes )

plot( ttemps, title='Temperature, read via XPath calls into XML file' )