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xmlcsvantxquerybasex

Iteration in Ant, command line xquery function call

I have an xml-file - call it myXML.xml - like this:

<?xml version="1.0" encoding="UTF-8"?>
<Metrics info1="1" info2="2" info3="3" xmlns="http://metrics.sourceforge.net/2003/Metrics-First-Flat">
    <Metric id = "NORM" description ="Number of Overridden Methods">
      <Values per = "type" total = "135" avg = "0.452" stddev = "0.94" max = "5">
        <Value name="a" source ="a.java" package ="package.a" value ="1"/>
        <Value name="b" source ="b.java" package ="package.b" value ="34"/>
        <Value name="c" source ="c.java" package ="package.c" value ="4"/>
        <Value name="d" source ="d.java" package ="package.d" value ="99"/>
        <Value name="e" source ="e.java" package ="package.e" value ="99"/>
        <Value name="f" source ="f.java" package ="package.f" value ="99"/>
        <Value name="g" source ="g.java" package ="package.g" value ="99"/>
      </Values>
    </Metric>

    <Metric id = "NOI" description ="Number of Overridden Methods">
      <Values per = "type" total = "135" avg = "0.452" stddev = "0.94" max = "5">
        <Value name="a" source ="a.java" package ="package.a" value ="10"/>
        <Value name="b" source ="b.java" package ="package.b" value ="340"/>
        <Value name="c" source ="c.java" package ="package.c" value ="40"/>
        <Value name="d" source ="d.java" package ="package.d" value ="990"/>
      </Values>
    </Metric>
</Metrics>

Because I have to evaluate dozens of such files (like myXML.xml) over dozens of attributes (here id=NORM and id=NOI) I tried to automate this in Apache Ant.

The best case scenario would be to get for a fixed file (myXML.xml) a csv-file in return - which will be saved as myXML.csv - and looks something like

NORM 1, 34, 4, 99, 99, 99, 99
NOI 10, 340, 40, 990

To approach this, I thought to create a property file <property file="metrics.properties"/> which looks like

p_1 = NORM
p_2 = NOI
...
p_N = VG

where N is arbitrary, so Ant has to figure out N (in the small example here N=2) and create the csv-file as mentioned above over all p_i's. Further I guess I should rewrite the below xquery as a function of the file (myXML.xml) and NORM and run it from the command line. But I don't see how to do either of this.

The following xquery is partially doing what I am interested in:

declare option db:stripns 'true';
for $x in doc("myXML.xml")/Metrics/Metric[@id="NORM"]/Values//Value/@value
return data($x)

but both myXML.xml and NORM are fixed and the output is simply 1 34 4 99 99 99 99 . I saved this file in query.xq and ran it in Ant:

<target name="ant" depends="#1">
 <echo> ant </echo>
 <exec executable="${pathToAnt}/basex.bat" dir="${basedir}" error="${basedir}/output/error.txt">
  <arg value = "query.xq"/> 
  <redirector output="${basedir}/output/myXML.csv" alwayslog="true"/>
 </exec>
</target>

That's what I have - little far from what I intend to get.

I hope it's clear what I am trying to achieve. I am new to xquery aswell to ant and I am using BaseX (not a must) under Windows, thus this is quite challenging to me ;-).

Thanks a lot for any help, hints, questions, etc.

Solution

  • Thanks for your help. I figured it out:

    A for loop can be done using http://ant-contrib.sourceforge.net/tasks/tasks/for.html. I did an iteration over all my source files (their names are stored in fileNames) which looks like

    <for list="${fileNames}" delimiter="," param="nameIter">
 <sequential>
  <echo> loop over fileNames: nameIter=@{nameIter} </echo>
  <exec executable="${pathToAnt}/basex.bat" dir="${basedir}" error="${basedir}/output/error_baseX/@{nameIter}Error.txt">
   <arg value="-b$importList=${metricsList}" />
   <arg value="-b$name=@{nameIter}"/>
   <arg value="./source_data/data/query.xq"/>
   <redirector output="${basedir}/output/@{nameIter}.csv" alwayslog="true"/>
  </exec>
 </sequential>
</for>

    Now, the exec-part runs the following xquery from command line, where the variable metricsList consist of all the metrics I am interested in. In the xml above for instance this would be metricsList=NORM,NOI. The xquery file query.xq is

    declare option db:stripns 'true';
declare variable $name external;
declare variable $importList external;
declare variable $list as xs:string* := tokenize($importList, ',');
for $i in $list
let $x := doc($name)/Metrics/Metric 
let $nl := "&#10;" (: this is a newline:)
return ($nl,data($x[@id=$i]/Values/../@id), data($x[@id=$i]/Values/Value/@value))