# $Id: Tree.pm,v 1.2 2003-07-31 07:54:51 matt Exp $
package XML::Parser::Style::Tree;
$XML::Parser::Built_In_Styles{Tree} = 1;
sub Init {
my $expat = shift;
$expat->{Lists} = [];
$expat->{Curlist} = $expat->{Tree} = [];
}
sub Start {
my $expat = shift;
my $tag = shift;
my $newlist = [ {@_} ];
push @{ $expat->{Lists} }, $expat->{Curlist};
push @{ $expat->{Curlist} }, $tag => $newlist;
$expat->{Curlist} = $newlist;
}
sub End {
my $expat = shift;
my $tag = shift;
$expat->{Curlist} = pop @{ $expat->{Lists} };
}
sub Char {
my $expat = shift;
my $text = shift;
my $clist = $expat->{Curlist};
my $pos = $#$clist;
if ( $pos > 0 and $clist->[ $pos - 1 ] eq '0' ) {
$clist->[$pos] .= $text;
}
else {
push @$clist, 0 => $text;
}
}
sub Final {
my $expat = shift;
delete $expat->{Curlist};
delete $expat->{Lists};
$expat->{Tree};
}
1;
__END__
=head1 NAME
XML::Parser::Style::Tree - Tree style parser
=head1 SYNOPSIS
use XML::Parser;
my $p = XML::Parser->new(Style => 'Tree');
my $tree = $p->parsefile('foo.xml');
=head1 DESCRIPTION
This module implements XML::Parser's Tree style parser.
When parsing a document, C<parse()> will return a parse tree for the
document. Each node in the tree
takes the form of a tag, content pair. Text nodes are represented with
a pseudo-tag of "0" and the string that is their content. For elements,
the content is an array reference. The first item in the array is a
(possibly empty) hash reference containing attributes. The remainder of
the array is a sequence of tag-content pairs representing the content
of the element.
So for example the result of parsing:
<foo><head id="a">Hello <em>there</em></head><bar>Howdy<ref/></bar>do</foo>
would be:
Tag Content
==================================================================
[foo, [{}, head, [{id => "a"}, 0, "Hello ", em, [{}, 0, "there"]],
bar, [ {}, 0, "Howdy", ref, [{}]],
0, "do"
]
]
The root document "foo", has 3 children: a "head" element, a "bar"
element and the text "do". After the empty attribute hash, these are
represented in it's contents by 3 tag-content pairs.
=cut
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