You can use the XML::Rules->inferRulesFromExample() (or XML::Rules->inferRulesFromDTD() if you have the DTD) to get the basic set of rules for the document and see what data structure would that create (using Data::Dumper). Then you can start tweaking the rules to create a nicer structure. For example, if you do not need the author names split into parts and only want the valid ones you can delete the 'Author' from the list of tags with the 'as array' built-in rule and add a rule like this:

  'Author' => sub {
    return unless $_[1]->{ValidYN} eq 'Y';
    return "$_[1]->{ForeName} $_[1]->{LastName}";
  },
[download]

And then continue tweaking the rules to filter the stuff you are not interested in, format stuff the way you want, rename hash keys etc.

Hi again.
I have taken XML::Rules for a ride, and it is really nice. It also looks very fast. All in all, a great tool.
But it did take me a while to get the inner logic of how it works, despite your evident efforts at writing the documentation. It is in the end excellent as a reference, but as far as I am concerned it lacked a bit in terms of being a tutorial, although I understand that the matter is complex and not easy to explain simply.
What was not evident, is how one deals with a frequent case where a given <tag> can be a subtag of different parent tags, and needs to be interpreted differently depending on that, like <average-color> below :

<fruits>
  <average-color>purple</average-color>
  <fruit type="banana">
    <average-color>yellow</average-color>
  </fruit>
  <fruit type="apple">
    <average-color>greenish</average-color>
  </fruit>
</fruits>
[download]


I could never get the "somewhat x-path-like" tags to work, so I resorted to :

  'average-color' => sub {
      if ($_[2]->[-1] eq 'fruit') {
        # parent tag is <fruit>
        return 'fruit-average-color' => $_[1]->{_content};
      } elsif ($_[2]->[-1] eq 'fruits') {
        # parent tag is <fruits>
        return 'global-average-color' => $_[1]->{_content};
      } else {
        # anything else, discard
        return undef;
      }
   },
[download]


Another aspect a bit mysterious is how exactly the following construct actually works :

  'tag' => sub {
     return '@'.$_[0] => $_[1]->{_content};
  },
[download]


I mean, I know it works and returns the contents of <tag>s as an array, but the way in which it does that is a bit mysterious, even after looking at the module code (I must admit that a lot remains mysterious to me, after looking at the code though).

All in all, thanks for the tip, and thanks for the module. I will re-use it.

Thanks. I'll see if I can improve the docs. Especially regarding the "x-path-like" stuff. That thing is fairly underdocumented.

The code without using the "helper" would be

use XML::Rules;

my $parser = XML::Rules->new(
    stripspaces => 7,
    rules => {
        fruit => 'as array',
        fruits => 'pass no content',
        'average-color' => [
            'fruit' => sub {return 'fruit-average-color' => $_[1]->{_c
+ontent}},
            'fruits' => sub {return 'global-average-color' => $_[1]->{
+_content}},
            sub {},
        ]
    }
);

my $data = $parser->parse(\*DATA);
use Data::Dumper;

print Dumper($data);

__DATA__
<fruits>
  <average-color>purple</average-color>
  <fruit type="banana">
    <average-color>yellow</average-color>
  </fruit>
  <fruit type="apple">
    <average-color>greenish</average-color>
  </fruit>
</fruits>
[download]

Jenda


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