how-to parse xml file with perl and XML::Simple module

use strict ; 

use warnings ; 

use XML::Simple;        #ppm install XML::Simple

use Data::Dumper; #ppm install Data::Dumper - used just for debugging

sub main 

{

print "START SCRIPT " ; 

my $fileToParse = 'C:/Temp/CDIP/scripts/perl/nps_all_workflows.xml' ; 

# create object

my $objXml= new XML::Simple;

# read XML file

my $data = $objXml->XMLin("$fileToParse");

# print "\n FirstLevel is " . $objXml->{'POWERMART'} ; 

printHashKeyValues ($data ) ;  

} #eof main 

#for each 

sub printHashKeyValues  

{

my $refHash = shift ; 

my $parentKey = shift ; 

my $parentValue = shift ; 

while( my ($key, $value) = each %$refHash) 

{

if ( defined ( $key ) )

{

if ( ref ($refHash->{"$key"}) eq 'HASH'  ) 

{

my $newRefHash = $refHash->{"$key"} ; 

print " \n The key is a hash " ; 

printHashKeyValues ($newRefHash , $key , $value) ;

}

if ( ref ($refHash->{"$key"}) eq 'ARRAY'  ) 

{

print " \n the key is an ARRAY " ; 

printArrayValues ( $refHash->{"$key"} ) ; 

}

} #eof  if ( defined ( $key ))

if ( defined ( $value) )

{

if (  ref ($refHash->{"$value"}) eq 'HASH'  ) 

{

my $newRefHash = $refHash->{"$value"} ; 

print " \n The value is a hash " ; 

printHashKeyValues ($newRefHash , $key , $value) ;

}

if ( ref ($refHash->{"$value"}) eq 'ARRAY'  ) 

{

print " \n the value is an ARRAY " ; 

printArrayValues ( $refHash->{"$value"} ) ; 

}

} #eof if defined ( $value ) 

print "\n key: $key, value: $value.\n";

} #eof while

} #eof sub 

#Foreach element of the array if it is array call itself recursively 

# if the element is a hash ref print the hash recursively 

sub printArrayValues

{

my $arrRef = shift ; 

my @array = @$arrRef; 

my $parrentArrayElement = shift ; 

print "printArrayValues CALLED " ;

foreach my $arrayElement ( @array ) 

{

if (defined ( $arrayElement ) )

{

if   ( ref ($arrayElement) eq 'HASH'  ) 

{

print " \n The  \$arrayElement is a hash FROM THE ARRAY " ; 

printHashKeyValues ($arrayElement ) ;  

} #eof if 

if   ( ref ($arrayElement) eq 'ARRAY'  ) 

{

print " \n The \$arrayElement is a ARRAY  FROM THE ARRAY " ; 

printArrayValues ($arrayElement ) ;  

} #eof if 

print "\n \$arrayElement is $arrayElement " ; 

} #eof if ( defined ( $arrayElement ) ) 

} #eof foreach 

} #eof sub 

# print output

#print Dumper($data);

#action !!

main();

1 ; 

#Purpose: 

#open an xml file and parse it with XML::Simple

#since the XML::Simple module represents the xml document as a data structure collection of hash of hashes and array 

#go trough the initial hash and if the key or the value are hashes print hash recursively 

# if the key or the value are array refs print hte array refs recursively 

#Version 1.0 

#TODO: add recognition for parent keys and values