XML Parser issue

siva kumar has asked for the wisdom of the Perl Monks concerning the following question:

I have issue with XML Parsing. The following is the xml content.

<story>
           <page>
                <author>Author 1 </author>
                <keywords>Keyword1 </keywords>
                <headline>Headline1 </headline>
                <image> Image1 </image>
                <description>Desc 1 </description>
            </page>
            <page>
                <author>Author 2</author>
                <keywords>Keyword2 </keywords>
                <headline>Headline 2 </headline>
               <image> Image2 </image>
               <description>Decs 2 </description>
            </page>
</story>
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I need array of hash references. Means the above xml will produce two records in hash format. The two hash references will be pushed to array. I have written the below parser. But the result render only one record. The second record is empty. Please suggest.

#!/home/y/bin/perl5.8.5 -w

use XML::Parser;
use strict;
use Data::Dumper;


my $parser = new XML::Parser(ErrorContext => 2);

my $xmlStr = "";
my $pageFlag =0 ;
my $authorFlag = 0;
my $titleFlag = 0;
my $descFlag = 0;
my $headlineFlag = 0;
my $imageFlag = 0 ;
my $keywordFlag = 0;
my @pagesArray = ();
my %hash = ();
my $pageEnd = 0 ;

my $authorTxt  = '';
my $keywordTxt = '';
my $headlineTxt = '';
my $imageTxt ='';
my $descTxt = '';


$xmlStr = "
<story>
           <page>
                <author>Author 1 </author>
                <keywords>Keyword1 </keywords>
                <headline>Headline1 </headline>
                <image> Image1 </image>
                <description>Desc 1 </description>
            </page>
            <page>
                <author>Author 2</author>
                <keywords>Keyword2 </keywords>
                <headline>Headline 2 </headline>
               <image> Image2 </image>
               <description>Decs 2 </description>
            </page>
</story>";

$parser->setHandlers(
                         Start => \&start_handler,
                         Char => \&char_handler,
                         End => \&end_handler);
                $parser->parse($xmlStr);

print Dumper @pagesArray;
exit;



sub char_handler
{
   my ($p, $data) = @_;
     if($pageFlag ==1 && $authorFlag ==1 ){
        $authorTxt  .= $data;
     }
     if($pageFlag ==1 && $keywordFlag ==1 ){
        $keywordTxt .= $data;
     }
     if($pageFlag ==1 && $headlineFlag ==1 ){
        $headlineTxt .= $data;
     }
     if($pageFlag ==1 && $imageFlag ==1 ){
        $imageTxt .= $data;
     }
     if($pageFlag ==1 && $descFlag ==1 ){
        $descTxt .= $data;
     }

}
sub start_handler
{

   my ($p, $data) = @_;
   if($data =~ /^(page)$/) {
         %hash = ();
         $pageFlag = 1;
   }
   if($data =~ /^author$/)      {
        $authorFlag = 1;
   }
   if($data =~ /^keywords$/)      {
        $keywordFlag = 1;
   }
   if($data =~ /^headline$/)      {
        $headlineFlag  = 1;
   }
   if($data =~ /^image$/)      {
        $imageFlag  = 1;
   }
   if($data =~ /^description$/)      {
        $descFlag = 1;
   }

}
sub end_handler
{
my ($p, $data) = @_;
   if($data =~ /^author$/)      {
        $hash{author} = $authorTxt;
        $authorTxt = '';
        print "Author -- $hash{author} \n";
        $authorFlag = 0;
   }
   if($data =~ /^keywords$/)      {
        $hash{keywords} = $keywordTxt;
        $keywordTxt = '';
        print "Keyword  -- $hash{keywords}\n";
        $keywordFlag = 0;
   }
   if($data =~ /^headline$/)      {
        $hash{headline} = $headlineTxt;
        $headlineTxt = '';
        print "Head -- $hash{headline}\n";
        $headlineFlag  = 0;
   }
   if($data =~ /^image$/)      {
        $hash{image} = $imageTxt;
        $imageTxt = '';
        print "Image  -- $hash{image}\n";
        $imageFlag  = 0;
   }
   if($data =~ /^description$/)      {
        $hash{description} = $descTxt;
        $descTxt ='';
        print "Desc   -- $hash{description}\n";
        $descFlag = 0;
    }
    if($data =~ /^page$/)   {
                push(@pagesArray,\%hash);
    }
}
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Re: XML Parser issue
by GrandFather (Saint) on Jul 05, 2007 at 08:39 UTC

You are pushing multiple references to the same hash. You need to create a new hash for each page. A small change that does that is to change

    if($data =~ /^page$/)   {
                push(@pagesArray,\%hash);
    }
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to:

    if($data =~ /^page$/)   {
        push @pagesArray, {%hash};
        %hash = ();
    }
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which simply creates a copy of the hash.

DWIM is Perl's answer to Gödel

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Re: XML Parser issue
by rg0now (Chaplain) on Jul 05, 2007 at 12:28 UTC

I need array of hash references. Means the above xml will produce two records in hash format. The two hash references will be pushed to array. I have written the below parser. But the result render only one record. The second record is empty. Please suggest.

XML::Simple

#!/usr/bin/perl

use warnings;
use strict;

use XML::Simple;
use Data::Dumper;

my $xml = XMLin(
    \*DATA,
    ForceArray => [ 'page' ],
);
print Dumper $xml->{page};

__DATA__
<story>
           <page>
                <author>Author 1 </author>
                <keywords>Keyword1 </keywords>
                <headline>Headline1 </headline>
                <image> Image1 </image>
                <description>Desc 1 </description>
            </page>
            <page>
                <author>Author 2</author>
                <keywords>Keyword2 </keywords>
                <headline>Headline 2 </headline>
               <image> Image2 </image>
               <description>Decs 2 </description>
            </page>
</story>

__OUTPUT__
$VAR1 = [
          {
            'keywords' => 'Keyword1 ',
            'author' => 'Author 1 ',
            'description' => 'Desc 1 ',
            'image' => ' Image1 ',
            'headline' => 'Headline1 '
          },
          {
            'keywords' => 'Keyword2 ',
            'author' => 'Author 2',
            'description' => 'Decs 2 ',
            'image' => ' Image2 ',
            'headline' => 'Headline 2 '
          }
        ];
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rg0now

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Re: XML Parser issue
by Jenda (Abbot) on Jul 05, 2007 at 12:40 UTC

Here's the solution using XML::Rules:

#!/usr/bin/perl
use warnings;
use strict;

use XML::Rules;
use Data::Dumper;

my $xml = do { local $/; <DATA>};

my $parser = XML::Rules->new(
    rules => [
        _default => 'content',
        page => 'no content array',
        story => 'pass no content',
    ]
);

my $data = $parser->parse($xml);
print Dumper $data->{page};

__DATA__
<story>
           <page>
                <author>Author 1 </author>
                <keywords>Keyword1 </keywords>
                <headline>Headline1 </headline>
                <image> Image1 </image>
                <description>Desc 1 </description>
            </page>
            <page>
                <author>Author 2</author>
                <keywords>Keyword2 </keywords>
                <headline>Headline 2 </headline>
               <image> Image2 </image>
               <description>Decs 2 </description>
            </page>
</story>
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If you wanted to process each <page> separately, as the file is parsed, you could do something like this:

#!/usr/bin/perl
use warnings;
use strict;

use XML::Rules;
use Data::Dumper;

my $xml = do { local $/; <DATA>};

my $parser = XML::Rules->new(
    rules => [
        _default => 'content trim',
        page => sub {
            print <<"*END*"
"$_[1]->{headline}" by $_[1]->{author}
Keywords: $_[1]->{keywords}
Description: $_[1]->{description}

*END*
        },
        story => '',
    ]
);

$parser->parse($xml);

__DATA__
...
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Jenda
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