[14078] | 1 | package HTML::PullParser;
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| 2 |
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| 3 | # $Id: PullParser.pm 22649 2010-08-17 02:03:34Z davidb $
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| 4 |
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| 5 | require HTML::Parser;
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| 6 | @ISA=qw(HTML::Parser);
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[22649] | 7 | #$VERSION = sprintf("%d.%02d", q$Revision: 22649 $ =~ /(\d+)\.(\d+)/);
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[14078] | 8 |
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| 9 | use strict;
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| 10 | use Carp ();
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| 11 |
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| 12 | sub new
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| 13 | {
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| 14 | my($class, %cnf) = @_;
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| 15 |
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| 16 | # Construct argspecs for the various events
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| 17 | my %argspec;
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| 18 | for (qw(start end text declaration comment process default)) {
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| 19 | my $tmp = delete $cnf{$_};
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| 20 | next unless defined $tmp;
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| 21 | $argspec{$_} = $tmp;
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| 22 | }
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| 23 | Carp::croak("Info not collected for any events")
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| 24 | unless %argspec;
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| 25 |
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| 26 | my $file = delete $cnf{file};
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| 27 | my $doc = delete $cnf{doc};
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| 28 | Carp::croak("Can't parse from both 'doc' and 'file' at the same time")
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| 29 | if defined($file) && defined($doc);
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| 30 | Carp::croak("No 'doc' or 'file' given to parse from")
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| 31 | unless defined($file) || defined($doc);
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| 32 |
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| 33 | # Create object
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| 34 | $cnf{api_version} = 3;
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| 35 | my $self = $class->SUPER::new(%cnf);
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| 36 |
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| 37 | my $accum = $self->{pullparser_accum} = [];
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| 38 | while (my($event, $argspec) = each %argspec) {
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| 39 | $self->SUPER::handler($event => $accum, $argspec);
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| 40 | }
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| 41 |
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| 42 | if (defined $doc) {
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| 43 | $self->{pullparser_str_ref} = ref($doc) ? $doc : \$doc;
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| 44 | $self->{pullparser_str_pos} = 0;
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| 45 | }
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| 46 | else {
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| 47 | if (!ref($file) && ref(\$file) ne "GLOB") {
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| 48 | require IO::File;
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| 49 | $file = IO::File->new($file, "r") || return;
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| 50 | }
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| 51 |
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| 52 | $self->{pullparser_file} = $file;
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| 53 | }
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| 54 | $self;
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| 55 | }
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| 56 |
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| 57 |
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| 58 | sub handler
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| 59 | {
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| 60 | Carp::croak("Can't set handlers for HTML::PullParser");
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| 61 | }
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| 62 |
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| 63 |
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| 64 | sub get_token
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| 65 | {
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| 66 | my $self = shift;
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| 67 | while (!@{$self->{pullparser_accum}} && !$self->{pullparser_eof}) {
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| 68 | if (my $f = $self->{pullparser_file}) {
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| 69 | # must try to parse more from the file
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| 70 | my $buf;
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| 71 | if (read($f, $buf, 512)) {
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| 72 | $self->parse($buf);
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| 73 | } else {
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| 74 | $self->eof;
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| 75 | $self->{pullparser_eof}++;
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| 76 | delete $self->{pullparser_file};
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| 77 | }
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| 78 | }
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| 79 | elsif (my $sref = $self->{pullparser_str_ref}) {
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| 80 | # must try to parse more from the scalar
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| 81 | my $pos = $self->{pullparser_str_pos};
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| 82 | my $chunk = substr($$sref, $pos, 512);
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| 83 | $self->parse($chunk);
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| 84 | $pos += length($chunk);
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| 85 | if ($pos < length($$sref)) {
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| 86 | $self->{pullparser_str_pos} = $pos;
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| 87 | }
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| 88 | else {
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| 89 | $self->eof;
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| 90 | $self->{pullparser_eof}++;
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| 91 | delete $self->{pullparser_str_ref};
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| 92 | delete $self->{pullparser_str_pos};
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| 93 | }
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| 94 | }
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| 95 | else {
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| 96 | die;
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| 97 | }
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| 98 | }
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| 99 | shift @{$self->{pullparser_accum}};
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| 100 | }
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| 101 |
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| 102 |
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| 103 | sub unget_token
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| 104 | {
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| 105 | my $self = shift;
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| 106 | unshift @{$self->{pullparser_accum}}, @_;
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| 107 | $self;
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| 108 | }
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| 109 |
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| 110 | 1;
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| 111 |
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| 112 |
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| 113 | __END__
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| 114 |
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| 115 | =head1 NAME
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| 116 |
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| 117 | HTML::PullParser - Alternative HTML::Parser interface
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| 118 |
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| 119 | =head1 SYNOPSIS
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| 120 |
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| 121 | use HTML::PullParser;
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| 122 |
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| 123 | $p = HTML::PullParser->new(file => "index.html",
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| 124 | start => 'event, tagname, @attr',
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| 125 | end => 'event, tagname',
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| 126 | ignore_elements => [qw(script style)],
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| 127 | ) || die "Can't open: $!";
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| 128 | while (my $token = $p->get_token) {
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| 129 | #...do something with $token
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| 130 | }
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| 131 |
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| 132 | =head1 DESCRIPTION
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| 133 |
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| 134 | The HTML::PullParser is an alternative interface to the HTML::Parser class.
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| 135 | It basically turns the HTML::Parser inside out. You associate a file
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| 136 | (or any IO::Handle object or string) with the parser at construction time and
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| 137 | then repeatedly call $parser->get_token to obtain the tags and text
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| 138 | found in the parsed document.
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| 139 |
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| 140 | The following methods are provided:
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| 141 |
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| 142 | =over 4
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| 143 |
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| 144 | =item $p = HTML::PullParser->new( file => $file, %options )
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| 145 |
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| 146 | =item $p = HTML::PullParser->new( doc => \$doc, %options )
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| 147 |
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| 148 | A C<HTML::PullParser> can be made to parse from either a file or a
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| 149 | literal document based on whether the C<file> or C<doc> option is
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| 150 | passed to the parser's constructor.
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| 151 |
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| 152 | The C<file> passed in can either be a file name or a file handle
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| 153 | object. If a file name is passed, and it can't be opened for reading,
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| 154 | then the constructor will return an undefined value and $! will tell
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| 155 | you why it failed. Otherwise the argument is taken to be some object
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| 156 | that the C<HTML::PullParser> can read() from when it needs more data.
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| 157 | The stream will be read() until EOF, but not closed.
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| 158 |
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| 159 | A C<doc> can be passed plain or as a reference
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| 160 | to a scalar. If a reference is passed then the value of this scalar
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| 161 | should not be changed before all tokens have been extracted.
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| 162 |
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| 163 | Next the information to be returned for the different token types must
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| 164 | be set up. This is done by simply associating an argspec (as defined
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| 165 | in L<HTML::Parser>) with the events you have an interest in. For
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| 166 | instance, if you want C<start> tokens to be reported as the string
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| 167 | C<'S'> followed by the tagname and the attributes you might pass an
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| 168 | C<start>-option like this:
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| 169 |
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| 170 | $p = HTML::PullParser->new(
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| 171 | doc => $document_to_parse,
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| 172 | start => '"S", tagname, @attr',
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| 173 | end => '"E", tagname',
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| 174 | );
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| 175 |
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| 176 | At last other C<HTML::Parser> options, like C<ignore_tags>, and
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| 177 | C<unbroken_text>, can be passed in. Note that you should not use the
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| 178 | I<event>_h options to set up parser handlers. That would confuse the
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| 179 | inner logic of C<HTML::PullParser>.
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| 180 |
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| 181 | =item $token = $p->get_token
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| 182 |
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| 183 | This method will return the next I<token> found in the HTML document,
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| 184 | or C<undef> at the end of the document. The token is returned as an
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| 185 | array reference. The content of this array match the argspec set up
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| 186 | during C<HTML::PullParser> construction.
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| 187 |
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| 188 | =item $p->unget_token( @tokens )
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| 189 |
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| 190 | If you find out you have read too many tokens you can push them back,
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| 191 | so that they are returned again the next time $p->get_token is called.
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| 192 |
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| 193 | =back
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| 194 |
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| 195 | =head1 EXAMPLES
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| 196 |
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| 197 | The 'eg/hform' script shows how we might parse the form section of
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| 198 | HTML::Documents using HTML::PullParser.
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| 199 |
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| 200 | =head1 SEE ALSO
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| 201 |
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| 202 | L<HTML::Parser>, L<HTML::TokeParser>
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| 203 |
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| 204 | =head1 COPYRIGHT
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| 205 |
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| 206 | Copyright 1998-2001 Gisle Aas.
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| 207 |
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| 208 | This library is free software; you can redistribute it and/or
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| 209 | modify it under the same terms as Perl itself.
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| 210 |
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| 211 | =cut
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