in reply to Which XML module to use for this scenario?

If it's just a quasi XML file that you're appending values to because there is no root node, then I'd suggest you use XML::Simple.

use XML::Simple;

use strict; 
use warnings; 

my $hash = {key => 1, content => "process a"};

print XMLout($hash, RootName => 'Parameter');

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If it's a fully valid xml file that you'll be reading and re-writing each time, then I'd use XML::Twig.

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Re^2: Which XML module to use for this scenario?
by jellisii2 (Hermit) on Apr 21, 2011 at 17:54 UTC
    ++ for XML::Twig. If it can't be done with Twig, I don't consider it XML. May $DEITY bless mirod.
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Re^2: Which XML module to use for this scenario?
by Perllace (Acolyte) on Apr 23, 2011 at 06:57 UTC
    Thanks wind, Please have a look at this 
    

use XML::Simple;
use strict;
use warnings;

my ($id, $value);

#group 1 paramters 
$id = "ID1";
$value = "Recording INformation";
getParameter($id, $value);
$id = "ID2";
$value = "Pausing INformation Record ";
getParameter($id, $value);
$value = "Information Loading";
getParameter($id, $value);
$value = "Information loading Complete";

#From here group 2 parameter starts
my $id = 2;
$value = "Picture loading";
getParameter($id, $value);
my $id = 3;
$value = "Picture loading complete";
getParameter($id, $value);
#Group 2 parameters end.

sub getParameter

{
    my ( $id,$value) = @_;
    my $hash = {
        'Key' => $id,
        'Value' => $value
    };

my $xml = { Parameter => [] };
push( @{ $xml->{Parameter} }
    , { key => $hash->{Key}, content => $hash->{Value} }
    );
    
    print XMLout( $xml, RootName => 'Parameter' );

}

    [download]

    Right now, the output that i get is something like 
    
 <Parameter key="ID1">Recording INformation</Parameter>
 <Parameter key="ID2">Pausing INformation Record</Parameter>
 <Parameter key="ID2">Information Loading</Parameter>
 <Parameter key="ID2">Information loading Complete</Parameter>

    [download]
    If I need something like 
    <Parameters>
- <ParameterGroup ID="Group1">
  <Parameter key="Key1">Some Value</Parameter> 
  <Parameter key="Key2">Some Value</Parameter> 
  <Parameter key="Key3">Some Value</Parameter> 
  </ParameterGroup>
- <ParameterGroup ID="Group2">
  <Parameter key="Key1">Some Value</Parameter> 
  <Parameter key="Key2">Some Value</Parameter> 
  <Parameter key="Key3">Some Value</Parameter> 
  </ParameterGroup>
  </Parameters>

    [download]
    What do I have to do? Thanks
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      To get XML of a specific format, work backwards. Start with xml exactly how you like it and see what type of data structure it makes:

      #!/usr/bin/perl
use Data::Dumper;
use XML::Simple;

use strict;
use warnings;

my $data = do {local $/; <DATA>};
my $xml = XMLin($data);
print Dumper($xml);

__DATA__
<Parameters>
<ParameterGroup ID="Group1">
<Parameter key="Key1">Some Value</Parameter> 
<Parameter key="Key2">Some Value</Parameter> 
<Parameter key="Key3">Some Value</Parameter> 
</ParameterGroup>
<ParameterGroup ID="Group2">
<Parameter key="Key1">Some Value</Parameter> 
<Parameter key="Key2">Some Value</Parameter> 
<Parameter key="Key3">Some Value</Parameter> 
</ParameterGroup>
</Parameters>

      [download]

      Doing this shows us our data structure. Now we just need to build it before translating to xml:

      #!/usr/bin/perl

use XML::Simple;

use strict;
use warnings;

my $xml = { ParameterGroup => [
    {
        ID => 'Group1',
        Parameter => {
            Key1 => {content => 'Some Value'},
            Key2 => {content => 'Some Value'},
            Key3 => {content => 'Some Value'},
        },
    },
    {
        ID => 'Group1',
        Parameter => {
            Key1 => {content => 'Some Value'},
            Key2 => {content => 'Some Value'},
            Key3 => {content => 'Some Value'},
        },
    },
]};

print XMLout($xml,
    RootName => 'Parameters',
    KeyAttr => 'key',
);

      [download]

      Outputs

      <Parameters>
  <ParameterGroup ID="Group1">
    <Parameter key="Key1">Some Value</Parameter>
    <Parameter key="Key2">Some Value</Parameter>
    <Parameter key="Key3">Some Value</Parameter>
  </ParameterGroup>
  <ParameterGroup ID="Group1">
    <Parameter key="Key1">Some Value</Parameter>
    <Parameter key="Key2">Some Value</Parameter>
    <Parameter key="Key3">Some Value</Parameter>
  </ParameterGroup>
</Parameters>

      [download]
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        thanks wind.. this works.. but the user would have to specify the values of tags as an when he is scripting.. and therefore I cannot hard code the values inside the tag.. for this purpose..I have something like.. 
        $xml = { Parameter => [] };
push( @{ $xml->{Parameter} }
    , { key => $hash->{Key}, content => $hash->{Value} }
    );

        [download]
        but this prints something like 
         <Parameter key="ID1">Some Process a</Parameter>
  <Parameter key="ID2">Some Process b</Parameter>
  <Parameter key="ID3">Some Process c</Parameter>

        [download]
        if I also want the ParameterGroup ID to be given by the user how can i do it..
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