XML :: Simple order of output elements from a complex hash

Question

I have already seen several answers in different places regarding setting the order of returned XML elements XMLout. However, I cannot solve the problem using these answers / examples.

I have a script that should output some XML data, and some elements should be printed in a specific order. The hash is quite complex, and I could not achieve any results by overriding it sorted_keysinto XML::Simplean object. Well, I did, but not the way I wanted.

The code example is below, detailed information about the problem is given below the code.

#!/usr/bin/perl

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

package MyXMLSimple;
use base 'XML::Simple';

sub sorted_keys
{
 my ($self, $name, $hashref) = @_;
 # ... 
 return $self->SUPER::sorted_keys($name, $hashref);
}

package main;

my $xmlParser = MyXMLSimple->new;

my $items = {
 'status' => 'OK',
 'fields' => {
  'i1' => {
   'header' => 'Header 1',
   'max_size' => '3'
  },
  'i2' => {
   'header' => 'Header 2',
   'max_size' => '8'
  }
 },
 'item_list' => {
  'GGG' => {
   'index' => '3',
   'i' => 3,
   'points' => {
    'p5' => {
     'data' => '10',
    }
   },
  },
  'AAA' => {
   'index' => '1',
   'i' => 2,
   'points' => {
    'p7' => {
     'data' => '22',
    }
   },
  },
  'ZZZ' => {
   'index' => '2',
   'i' => 1,
   'points' => {
    'p6' => {
     'data' => '15',
    }
   },
  }
 }
};

my $xml = $xmlParser->XMLout($items);
print "$xml";

So, the output of this script will be as follows:

<opt status="OK">
  <fields name="i1" header="Header 1" max_size="3" />
  <fields name="i2" header="Header 2" max_size="8" />
  <item_list name="AAA" i="2" index="1">
    <points name="p7" data="22" />
  </item_list>
  <item_list name="GGG" i="3" index="3">
    <points name="p5" data="10" />
  </item_list>
  <item_list name="ZZZ" i="1" index="2">
    <points name="p6" data="15" />
  </item_list>
</opt>

item_listelements are printed, and the output order is in alphabetical order by sorting by attribute name. The output order is AAA, GGG, ZZZ.

, ( , ) i. , ZZZ, AAA, GGG.

( Tie::...), . NoSort => 1, , .

, , , , sorted_keys. , , sorted_keys item_list. sorted_keys opt, -, Tie::.

, , Tie::IxHash, sorted_keys (re), item_list, ( ), .

- :

sub sorted_keys
{
 my ($self, $name, $hashref) = @_;
 if ($name eq "opt")
 {
  my $clist = { };
  tie %{$clist}, "Tie::IxHash";

  my @sorted_keys = sort { $hashref->{item_list}->{$a}->{i} <=> $hashref->{item_list}->{$b}->{i} } keys %{$hashref->{item_list}};
  foreach my $sorted_key (@sorted_keys)
  {
   $clist->{$sorted_key} = $hashref->{item_list}->{$sorted_key};
  }

  delete $hashref->{item_list};
  $hashref->{item_list} = $clist;
 }
 return $self->SUPER::sorted_keys($name, $hashref);
}

, ( , , ), , , Tie::IxHash , -/, / sorted_keys.

, , sorted_keys ( / ;), , -, .

, XML/Simple.pm sorted_keys, - . , , , name, i.

:)

Answer 1

, XML:: Simple. , XML-ish-. XML, , XML:: TreeBuilder, new_from_lol. XML:: LibXML, XML:: Twig, XML:: Writer...

Tie:: IxHash XML:: Simple , . . , - .

Answer 2

, hash_to_array? . http://perlmaven.com/xml-simple-sorting

, XML:: Simple hash_to_array. XML:: Simple.pm - :

package MyXMLSimple;      # my XML::Simple subclass
use base 'XML::Simple';

sub hash_to_array {
  my $self    = shift;
  my $parent  = shift;
  my $hashref = shift;

  my $arrayref = [];

  my($key, $value);

  if ( $parent eq "mytag" ) {
  my @keys = $self->{opt}->{nosort} ? keys %$hashref : sort {$a<=>$b} keys %$hashref;
  foreach $key (@keys) {
    $value = $hashref->{$key};
    return($hashref) unless(UNIVERSAL::isa($value, 'HASH'));

    if(ref($self->{opt}->{keyattr}) eq 'HASH') {
      return($hashref) unless(defined($self->{opt}->{keyattr}->{$parent}));
      push @$arrayref, $self->copy_hash(
        $value, $self->{opt}->{keyattr}->{$parent}->[0] => $key
      );
    }
    else {
      push(@$arrayref, { $self->{opt}->{keyattr}->[0] => $key, %$value });
    }
  }

  } else {
  my @keys = $self->{opt}->{nosort} ? keys %$hashref : sort keys %$hashref;
  foreach $key (@keys) {
    $value = $hashref->{$key};
    return($hashref) unless(UNIVERSAL::isa($value, 'HASH'));

    if(ref($self->{opt}->{keyattr}) eq 'HASH') {
      return($hashref) unless(defined($self->{opt}->{keyattr}->{$parent}));
      push @$arrayref, $self->copy_hash(
        $value, $self->{opt}->{keyattr}->{$parent}->[0] => $key
      );
    }
    else {
      push(@$arrayref, { $self->{opt}->{keyattr}->[0] => $key, %$value });
    }
  }
  }

  return($arrayref);
}

my $xmlParser = MyXMLSimple->new(KeepRoot => 1);
$xmlParser->XMLout($self->{_xml}, KeyAttr => { ...

, , "i" KeyAttr 5 , , - :)