Re: XML::Simple design decisions

[alw]

I have a problem with array folding that I could only solve by subclassing XML::Simple and hardcoding a return in the array_to_hash method.

sub array_to_hash {
.
.
.

  # Or assume keyattr => [ .... ]

 else {
  ELEMENT: for($i = 0; $i < @$arrayref; $i++)  {
   return ($arrayref) if $arrayref->[$i]{name} eq 'e_im_dev_io_entry';
+   #this line was added to jump out
   return($arrayref) unless(UNIVERSAL::isa($arrayref->[$i], 'HASH'));
.
.
.
}

If an attribute called "name" has the same value in multiple nested elements, then only one attribute will remain after the array folding. This example is only a part of a larger xml file. I don't want to use KeyAttr=>[] which does prevent the folding, since in other parts of the file, the array folding is desirable. I only want to prevent array folding if the attribute value is equal to "something". I have tried many options with no success. Am I missing something, or is subclassing the only way?

 <?xml version="1.0" encoding="UTF-8" standalone="no" ?>
<Report address="Address" name="IM Report" productID="INTRFC-MGR01">
   <Entry detail="4" name="e_im_dev_io_entry">
     <Text>Device Handle: 2</Text>
   </Entry>
   <Entry detail="4" name="e_im_dev_io_entry">
     <Text>Device Handle: 5</Text>
   </Entry>
</Report>
_______________________________________________
Options used were: none No good, I lost one element

$VAR1 = {
          'Entry' => {
                     'e_im_dev_io_entry' => {
                                            'detail' => '4',
                                            'Text' => 'Device Handle: 
+5'
                                          }
                   },
          'name' => 'IM Report',
          'address' => 'Address',
          'productID' => 'INTRFC-MGR01'
        };
_______________________________________________
Options used were: KeyAttr=>[]  This is what I want.

$VAR1 = {
          'Entry' => [
                     {
                       'detail' => '4',
                       'name' => 'e_im_dev_io_entry',
                       'Text' => 'Device Handle: 2'
                     },
                     {
                       'detail' => '4',
                       'name' => 'e_im_dev_io_entry',
                       'Text' => 'Device Handle: 5'
                     }
                   ],
          'name' => 'IM Report',
          'address' => 'Address',
          'productID' => 'INTRFC-MGR01'
        };

I would like the output to be identical to the last example. I don't want to lose any elements. Again, this is just a small piece of a much larger xml document. There are lots of Entry elements so I can't use KeyAttr {...}

[Jenda]

You could also use XML::Rules instead of XML::Simple as it gives you more detailed control over what data structure gets generated.

Something like:

use XML::Rules;
 # at least 0.22 (for the stripspaces)
 # see http://www.perlmonks.org/?node_id=658971
my $parser = XML::Rules->new(
    rules => [
        Text => 'content',
        Entry => 'as array',
        Report => 'pass',
        Other => sub {return delete($_[1]->{name}) => $_[1]},
    ],
    stripspaces  => 3,
);

my $data = $parser->parse(\*DATA);

use Data::Dumper;
print Dumper($data);

__DATA__
<?xml version="1.0" encoding="UTF-8" standalone="no" ?>
<Report address="Address" name="IM Report" productID="INTRFC-MGR01">
   <Entry detail="4" name="e_im_dev_io_entry">
     <Text>Device Handle: 2</Text>
   </Entry>
   <Entry detail="4" name="e_im_dev_io_entry">
     <Text>Device Handle: 5</Text>
   </Entry>
   <Other detail="4" name="first">
     <Text>Device Handle: 5</Text>
   </Other>
   <Other detail="4" name="second">
     <Text>Device Handle: 5</Text>
   </Other>
</Report>

It doesn't try to guess as XML::Simple does so it's more work though. (In not yet released 0.23 the rule for the Other tag will be just Other => 'by name',.)

[alw]

Thanks Jenda, that module works very well for me. One more point I would like to make. With XML::Simple and my xml file that I am working with, I can't use ForceArray => 'Entry' either for some reason; it hangs the script. I do not have that problem with XML::Rules.

[ysth]

Could you also show the output you actually want? Or is it identical to the KeyAttr=>[] output?