HTML::Parser error
am 01.12.2005 17:31:16 von osirisphnxI recently installed PERL on my system but am having a problem with the
parser.pm file. Whenever I try to run a script the following error
shows up"
Can't locate object method "empty_element_tags" via package
"HTML::TokeParser" at C:/Perl/site/lib/HTML/Parser.pm line 80.
I tried looking for an answer on the web, but no go. I tried searching
this Usenet group, but again I couldn't find a solution. Below is a
copy of the code for you to examine.
Thanks for all of your help.
****************Begin Code***********************
package HTML::Parser;
# Copyright 1996-2005, Gisle Aas.
# Copyright 1999-2000, Michael A. Chase.
#
# This library is free software; you can redistribute it and/or
# modify it under the same terms as Perl itself.
use strict;
use vars qw($VERSION @ISA);
$VERSION = '3.46'; # $Date: 2005/10/24 11:17:49 $
require HTML::Entities;
require XSLoader;
XSLoader::load('HTML::Parser', $VERSION);
sub new
{
my $class = shift;
my $self = bless {}, $class;
return $self->init(@_);
}
sub init
{
my $self = shift;
$self->_alloc_pstate;
my %arg = @_;
my $api_version = delete $arg{api_version} || (@_ ? 3 : 2);
if ($api_version >= 4) {
require Carp;
Carp::croak("API version $api_version not supported " .
"by HTML::Parser $VERSION");
}
if ($api_version < 3) {
# Set up method callbacks compatible with HTML-Parser-2.xx
$self->handler(text => "text", "self,text,is_cdata");
$self->handler(end => "end", "self,tagname,text");
$self->handler(process => "process", "self,token0,text");
$self->handler(start => "start",
"self,tagname,attr,attrseq,text");
$self->handler(comment =>
sub {
my($self, $tokens) = @_;
for (@$tokens) {
$self->comment($_);
}
}, "self,tokens");
$self->handler(declaration =>
sub {
my $self = shift;
$self->declaration(substr($_[0], 2, -1));
}, "self,text");
}
if (my $h = delete $arg{handlers}) {
$h = {@$h} if ref($h) eq "ARRAY";
while (my($event, $cb) = each %$h) {
$self->handler($event => @$cb);
}
}
# In the end we try to assume plain attribute or handler
while (my($option, $val) = each %arg) {
if ($option =~ /^(\w+)_h$/) {
$self->handler($1 => @$val);
}
elsif ($option =~
/^(text|start|end|process|declaration|comment)$/) {
require Carp;
Carp::croak("Bad constructor option '$option'");
}
else {
$self->$option($val);
}
}
return $self;
}
sub parse_file
{
my($self, $file) = @_;
my $opened;
if (!ref($file) && ref(\$file) ne "GLOB") {
# Assume $file is a filename
local(*F);
open(F, $file) || return undef;
binmode(F); # should we? good for byte counts
$opened++;
$file = *F;
}
my $chunk = '';
while (read($file, $chunk, 512)) {
$self->parse($chunk) || last;
}
close($file) if $opened;
$self->eof;
}
sub netscape_buggy_comment # legacy
{
my $self = shift;
require Carp;
Carp::carp("netscape_buggy_comment() is deprecated. " .
"Please use the strict_comment() method instead");
my $old = !$self->strict_comment;
$self->strict_comment(!shift) if @_;
return $old;
}
# set up method stubs
sub text { }
*start = \&text;
*end = \&text;
*comment = \&text;
*declaration = \&text;
*process = \&text;
1;
__END__
=head1 NAME
HTML::Parser - HTML parser class
=head1 SYNOPSIS
use HTML::Parser ();
# Create parser object
$p = HTML::Parser->new( api_version => 3,
start_h => [\&start, "tagname, attr"],
end_h => [\&end, "tagname"],
marked_sections => 1,
);
# Parse document text chunk by chunk
$p->parse($chunk1);
$p->parse($chunk2);
#...
$p->eof; # signal end of document
# Parse directly from file
$p->parse_file("foo.html");
# or
open(my $fh, "<:utf8", "foo.html") || die;
$p->parse_file($fh);
=head1 DESCRIPTION
Objects of the C
separate it from plain text (alias data content) in HTML
documents. As different kinds of markup and text are recognized, the
corresponding event handlers are invoked.
C
make it able to deal with the HTML that is actually "out there", and
it normally parses as closely as possible to the way the popular web
browsers do it instead of strictly following one of the many HTML
specifications from W3C. Where there is disagreement, there is often
an option that you can enable to get the official behaviour.
The document to be parsed may be supplied in arbitrary chunks. This
makes on-the-fly parsing as documents are received from the network
possible.
If event driven parsing does not feel right for your application, you
might want to use C
subclass that allows a more conventional program structure.
=head1 METHODS
The following method is used to construct a new C
=over
=item $p = HTML::Parser->new( %options_and_handlers )
This class method creates a new C
returns it. Key/value argument pairs may be provided to assign event
handlers or initialize parser options. The handlers and parser
options can also be set or modified later by the method calls described
below.
If a top level key is in the form "
assigns a handler to that event, otherwise it initializes a parser
option. The event handler specification value must be an array
reference. Multiple handlers may also be assigned with the 'handlers
=> [%handlers]' option. See examples below.
If new() is called without any arguments, it will create a parser that
uses callback methods compatible with version 2 of C
See the section on "version 2 compatibility" below for details.
The special constructor option 'api_version => 2' can be used to
initialize version 2 callbacks while still setting other options and
handlers. The 'api_version => 3' option can be used if you don't want
to set any options and don't want to fall back to v2 compatible
mode.
Examples:
$p = HTML::Parser->new(api_version => 3,
text_h => [ sub {...}, "dtext" ]);
This creates a new parser object with a text event handler subroutine
that receives the original text with general entities decoded.
$p = HTML::Parser->new(api_version => 3,
start_h => [ 'my_start', "self,tokens" ]);
This creates a new parser object with a start event handler method
that receives the $p and the tokens array.
$p = HTML::Parser->new(api_version => 3,
handlers => { text => [\@array, "event,text"],
comment => [\@array,
"event,text"],
});
This creates a new parser object that stores the event type and the
original text in @array for text and comment events.
=back
The following methods feed the HTML document
to the C
=over
=item $p->parse( $string )
Parse $string as the next chunk of the HTML document. The return
value is normally a reference to the parser object (i.e. $p).
Handlers invoked should not attempt to modify the $string in-place
until
$p->parse returns.
If an invoked event handler aborts parsing by calling $p->eof, then
$p->parse() will return a FALSE value.
=item $p->parse( $code_ref )
If a code reference is passed as the argument to be parsed, then the
chunks to be parsed are obtained by invoking this function repeatedly.
Parsing continues until the function returns an empty (or undefined)
result. When this happens $p->eof is automatically signalled.
Parsing will also abort if one of the event handlers calls $p->eof.
The effect of this is the same as:
while (1) {
my $chunk = &$code_ref();
if (!defined($chunk) || !length($chunk)) {
$p->eof;
return $p;
}
$p->parse($chunk) || return undef;
}
But it is more efficient as this loop runs internally in XS code.
=item $p->parse_file( $file )
Parse text directly from a file. The $file argument can be a
filename, an open file handle, or a reference to an open file
handle.
If $file contains a filename and the file can't be opened, then the
method returns an undefined value and $! tells why it failed.
Otherwise the return value is a reference to the parser object.
If a file handle is passed as the $file argument, then the file will
normally be read until EOF, but not closed.
If an invoked event handler aborts parsing by calling $p->eof,
then $p->parse_file() may not have read the entire file.
On systems with multi-byte line terminators, the values passed for the
offset and length argspecs may be too low if parse_file() is called on
a file handle that is not in binary mode.
If a filename is passed in, then parse_file() will open the file in
binary mode.
=item $p->eof
Signals the end of the HTML document. Calling the $p->eof method
outside a handler callback will flush any remaining buffered text
(which triggers the C
Calling $p->eof inside a handler will terminate parsing at that point
and cause $p->parse to return a FALSE value. This also terminates
parsing by $p->parse_file().
After $p->eof has been called, the parse() and parse_file() methods
can be invoked to feed new documents with the parser object.
The return value from eof() is a reference to the parser object.
=back
Most parser options are controlled by boolean attributes.
Each boolean attribute is enabled by calling the corresponding method
with a TRUE argument and disabled with a FALSE argument. The
attribute value is left unchanged if no argument is given. The return
value from each method is the old attribute value.
Methods that can be used to get and/or set parser options are:
=over
=item $p->attr_encoded
=item $p->attr_encoded( $bool )
By default, the C
entities for attribute values decoded. Enabling this attribute leaves
entities alone.
=item $p->boolean_attribute_value( $val )
This method sets the value reported for boolean attributes inside HTML
start tags. By default, the name of the attribute is also used as its
value. This affects the values reported for C
argspecs.
=item $p->case_sensitive
=item $p->case_sensitive( $bool )
By default, tagnames and attribute names are down-cased. Enabling this
attribute leaves them as found in the HTML source document.
=item $p->closing_plaintext
=item $p->closing_plaintext( $bool )
By default, "plaintext" element can never be closed. Everything up to
the end of the document is parsed in CDATA mode. This historical
behaviour is what at least MSIE does. Enabling this attribute makes
closing "" tag effective and the parsing process will
resume
after seeing this tag. This emulates gecko-based browsers.
=item $p->marked_sections
=item $p->marked_sections( $bool )
By default, section markings like are treated like
ordinary text. When this attribute is enabled section markings are
honoured.
There are currently no events associated with the marked section
markup, but the text can be returned as C
=item $p->strict_comment
=item $p->strict_comment( $bool )
By default, comments are terminated by the first occurrence of "-->".
This is the behaviour of most popular browsers (like Mozilla, Opera and
MSIE), but it is not correct according to the official HTML
standard. Officially, you need an even number of "--" tokens before
the closing ">" is recognized and there may not be anything but
whitespace between an even and an odd "--".
The official behaviour is enabled by enabling this attribute.
Enabling of 'strict_comment' also disables recognizing these forms as
comments:
=item $p->strict_end
=item $p->strict_end( $bool )
By default, attributes and other junk are allowed to be present on end
tags in a
manner that emulates MSIE's behaviour.
The official behaviour is enabled with this attribute. If enabled,
only whitespace is allowed between the tagname and the final ">".
=item $p->strict_names
=item $p->strict_names( $bool )
By default, almost anything is allowed in tag and attribute names.
This is the behaviour of most popular browsers and allows us to parse
some broken tags with invalid attribute values like:
By default, "LIST]" is parsed as a boolean attribute, not as
part of the ALT value as was clearly intended. This is also what
Mozilla sees.
The official behaviour is enabled by enabling this attribute. If
enabled, it will cause the tag above to be reported as text
since "LIST]" is not a legal attribute name.
=item $p->unbroken_text
=item $p->unbroken_text( $bool )
By default, blocks of text are given to the text handler as soon as
possible (but the parser takes care always to break text at a
boundary between whitespace and non-whitespace so single words and
entities can always be decoded safely). This might create breaks that
make it hard to do transformations on the text. When this attribute is
enabled, blocks of text are always reported in one piece. This will
delay the text event until the following (non-text) event has been
recognized by the parser.
Note that the C
segment of text and C
Since there might be ignored tags in between, these numbers can't be
used to directly index in the original document file.
=item $p->utf8_mode
=item $p->utf8_mode( $bool )
Enable this option when parsing raw undecoded UTF-8. This tells the
parser that the entities expanded for strings reported by C
C<@attr> and C
up compatible with the surrounding text.
If C
containing characters with code above 255 to the parse() method, and
the parse() method will croak if you try.
Example: The Unicode character "\x{2665}" is "\xE2\x99\xA5" when UTF-8
encoded. The character can also be represented by the entity
"♥" or "♥". If we feed the parser:
$p->parse("\xE2\x99\xA5♥");
then C
C
The later string is what you want.
This option is only available with perl-5.8 or better.
=item $p->xml_mode
=item $p->xml_mode( $bool )
Enabling this attribute changes the parser to allow some XML
constructs such as I
case when they are reported by the C
and suppresses special treatment of elements that are parsed as CDATA
for HTML.
I
sequence "/>". When recognized by C
artificial end event in addition to the start event. The C
the artificial end event will be empty and the C
be undefined even though the only element in the token array will have
the correct tag name.
I
simple ">" as is the case for HTML.
=back
As markup and text is recognized, handlers are invoked. The following
method is used to set up handlers for different events:
=over
=item $p->handler( event => \&subroutine, $argspec )
=item $p->handler( event => $method_name, $argspec )
=item $p->handler( event => \@accum, $argspec )
=item $p->handler( event => "" );
=item $p->handler( event => undef );
=item $p->handler( event );
This method assigns a subroutine, method, or array to handle an event.
Event is one of C
C
The C<\&subroutine> is a reference to a subroutine which is called to
handle
the event.
The C<$method_name> is the name of a method of $p which is called to
handle
the event.
The C<@accum> is an array that will hold the event information as
sub-arrays.
If the second argument is "", the event is ignored.
If it is undef, the default handler is invoked for the event.
The C<$argspec> is a string that describes the information to be
reported
for the event. Any requested information that does not apply to a
specific event is passed as C
is left unchanged.
The return value from $p->handler is the old callback routine or a
reference to the accumulator array.
Any return values from handler callback routines/methods are always
ignored. A handler callback can request parsing to be aborted by
invoking the $p->eof method. A handler callback is not allowed to
invoke the $p->parse() or $p->parse_file() method. An exception will
be raised if it tries.
Examples:
$p->handler(start => "start", 'self, attr, attrseq, text' );
This causes the "start" method of object $p to be called for 'start'
events.
The callback signature is $p->start(\%attr, \@attr_seq, $text).
$p->handler(start => \&start, 'attr, attrseq, text' );
This causes subroutine start() to be called for 'start' events.
The callback signature is start(\%attr, \@attr_seq, $text).
$p->handler(start => \@accum, '"S", attr, attrseq, text' );
This causes 'start' event information to be saved in @accum.
The array elements will be ['S', \%attr, \@attr_seq, $text].
$p->handler(start => "");
This causes 'start' events to be ignored. It also suppresses
invocations of any default handler for start events. It is in most
cases equivalent to $p->handler(start => sub {}), but is more
efficient. It is different from the empty-sub-handler in that
C
$p->handler(start => undef);
This causes no handler to be associated with start events.
If there is a default handler it will be invoked.
=back
Filters based on tags can be set up to limit the number of events
reported. The main bottleneck during parsing is often the huge number
of callbacks made from the parser. Applying filters can improve
performance significantly.
The following methods control filters:
=over
=item $p->ignore_elements( @tags )
Both the C
would be reported in between are suppressed. The ignored elements can
contain nested occurrences of itself. Example:
$p->ignore_elements(qw(script style));
The C