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For ddd2.pl
  Run on Tue May 25 16:52:24 2010
Reported on Tue May 25 16:56:54 2010

File /project/perl/lib/HTML/Parser.pm
Statements Executed 9236
Statement Execution Time 179ms
Subroutines — ordered by exclusive time
Calls P F Exclusive
Time
Inclusive
Time
Subroutine
4611197.4ms142msHTML::Parser::::initHTML::Parser::init
27666225.5ms25.5msHTML::Parser::::handlerHTML::Parser::handler (xsub)
4611118.0ms160msHTML::Parser::::newHTML::Parser::new
461127.42ms7.42msHTML::Parser::::_alloc_pstateHTML::Parser::_alloc_pstate (xsub)
922126.65ms6.65msHTML::Parser::::CORE:matchHTML::Parser::CORE:match (opcode)
461125.15ms5.15msHTML::Parser::::ignore_elementsHTML::Parser::ignore_elements (xsub)
712283µs986µsHTML::Parser::::parseHTML::Parser::parse (xsub)
71248µs48µsHTML::Parser::::eofHTML::Parser::eof (xsub)
0000s0sHTML::Parser::::BEGINHTML::Parser::BEGIN
0000s0sHTML::Parser::::__ANON__[:54]HTML::Parser::__ANON__[:54]
0000s0sHTML::Parser::::__ANON__[:60]HTML::Parser::__ANON__[:60]
0000s0sHTML::Parser::::netscape_buggy_commentHTML::Parser::netscape_buggy_comment
0000s0sHTML::Parser::::parse_fileHTML::Parser::parse_file
0000s0sHTML::Parser::::textHTML::Parser::text
Call graph for these subroutines as a Graphviz dot language file.
Line State
ments
Time
on line
Calls Time
in subs
Code
1package HTML::Parser;
2
3# Copyright 1996-2007, Gisle Aas.
4# Copyright 1999-2000, Michael A. Chase.
5#
6# This library is free software; you can redistribute it and/or
7# modify it under the same terms as Perl itself.
8
93107µs127µsuse strict;
# spent 27µs making 1 call to strict::import
1031.41ms1240µsuse vars qw($VERSION @ISA);
# spent 240µs making 1 call to vars::import
11
1216µs$VERSION = '3.56'; # $Date: 2007/01/12 09:18:31 $
13
1416µsrequire HTML::Entities;
15
1614µsrequire XSLoader;
17116.9ms116.8msXSLoader::load('HTML::Parser', $VERSION);
# spent 16.8ms making 1 call to XSLoader::load
18
19sub new
20
# spent 160ms (18.0+142) within HTML::Parser::new which was called 461 times, avg 347µs/call: # 461 times (18.0ms+142ms) by HTML::HeadParser::new at line 103 of HTML/HeadParser.pm, avg 347µs/call
{
21138317.5ms my $class = shift;
22 my $self = bless {}, $class;
23 return $self->init(@_);
# spent 142ms making 461 calls to HTML::Parser::init, avg 308µs/call
24}
25
26
27sub init
28
# spent 142ms (97.4+44.7) within HTML::Parser::init which was called 461 times, avg 308µs/call: # 461 times (97.4ms+44.7ms) by HTML::Parser::new at line 23, avg 308µs/call
{
29414947.1ms my $self = shift;
30 $self->_alloc_pstate;
# spent 7.42ms making 461 calls to HTML::Parser::_alloc_pstate, avg 16µs/call
31
32 my %arg = @_;
33 my $api_version = delete $arg{api_version} || (@_ ? 3 : 2);
34 if ($api_version >= 4) {
35 require Carp;
36 Carp::croak("API version $api_version not supported " .
37 "by HTML::Parser $VERSION");
38 }
39
40276662.9ms if ($api_version < 3) {
41 # Set up method callbacks compatible with HTML-Parser-2.xx
42 $self->handler(text => "text", "self,text,is_cdata");
# spent 5.89ms making 461 calls to HTML::Parser::handler, avg 13µs/call
43 $self->handler(end => "end", "self,tagname,text");
# spent 4.13ms making 461 calls to HTML::Parser::handler, avg 9µs/call
44 $self->handler(process => "process", "self,token0,text");
# spent 3.98ms making 461 calls to HTML::Parser::handler, avg 9µs/call
45 $self->handler(start => "start",
# spent 4.47ms making 461 calls to HTML::Parser::handler, avg 10µs/call
46 "self,tagname,attr,attrseq,text");
47
48 $self->handler(comment =>
49 sub {
50 my($self, $tokens) = @_;
51 for (@$tokens) {
52 $self->comment($_);
53 }
54 }, "self,tokens");
# spent 3.52ms making 461 calls to HTML::Parser::handler, avg 8µs/call
55
56 $self->handler(declaration =>
57 sub {
58 my $self = shift;
59 $self->declaration(substr($_[0], 2, -1));
60 }, "self,text");
# spent 3.48ms making 461 calls to HTML::Parser::handler, avg 8µs/call
61 }
62
63 if (my $h = delete $arg{handlers}) {
64 $h = {@$h} if ref($h) eq "ARRAY";
65 while (my($event, $cb) = each %$h) {
66 $self->handler($event => @$cb);
67 }
68 }
69
70 # In the end we try to assume plain attribute or handler
71 while (my($option, $val) = each %arg) {
7292232.7ms9226.65ms if ($option =~ /^(\w+)_h$/) {
# spent 6.65ms making 922 calls to HTML::Parser::CORE:match, avg 7µs/call
73 $self->handler($1 => @$val);
74 }
75 elsif ($option =~ /^(text|start|end|process|declaration|comment)$/) {
76 require Carp;
77 Carp::croak("Bad constructor option '$option'");
78 }
79 else {
80 $self->$option($val);
# spent 5.15ms making 461 calls to HTML::Parser::ignore_elements, avg 11µs/call
81 }
82 }
83
84 return $self;
85}
86
87
88sub parse_file
89{
90 my($self, $file) = @_;
91 my $opened;
92 if (!ref($file) && ref(\$file) ne "GLOB") {
93 # Assume $file is a filename
94 local(*F);
95 open(F, $file) || return undef;
96 binmode(F); # should we? good for byte counts
97 $opened++;
98 $file = *F;
99 }
100 my $chunk = '';
101 while (read($file, $chunk, 512)) {
102 $self->parse($chunk) || last;
103 }
104 close($file) if $opened;
105 $self->eof;
106}
107
108
109sub netscape_buggy_comment # legacy
110{
111 my $self = shift;
112 require Carp;
113 Carp::carp("netscape_buggy_comment() is deprecated. " .
114 "Please use the strict_comment() method instead");
115 my $old = !$self->strict_comment;
116 $self->strict_comment(!shift) if @_;
117 return $old;
118}
119
120# set up method stubs
121sub text { }
12219µs*start = \&text;
12315µs*end = \&text;
12416µs*comment = \&text;
12514µs*declaration = \&text;
12615µs*process = \&text;
127
128126µs1;
129
130__END__
131
132
133=head1 NAME
134
135HTML::Parser - HTML parser class
136
137=head1 SYNOPSIS
138
139 use HTML::Parser ();
140
141 # Create parser object
142 $p = HTML::Parser->new( api_version => 3,
143 start_h => [\&start, "tagname, attr"],
144 end_h => [\&end, "tagname"],
145 marked_sections => 1,
146 );
147
148 # Parse document text chunk by chunk
149 $p->parse($chunk1);
150 $p->parse($chunk2);
151 #...
152 $p->eof; # signal end of document
153
154 # Parse directly from file
155 $p->parse_file("foo.html");
156 # or
157 open(my $fh, "<:utf8", "foo.html") || die;
158 $p->parse_file($fh);
159
160=head1 DESCRIPTION
161
162Objects of the C<HTML::Parser> class will recognize markup and
163separate it from plain text (alias data content) in HTML
164documents. As different kinds of markup and text are recognized, the
165corresponding event handlers are invoked.
166
167C<HTML::Parser> is not a generic SGML parser. We have tried to
168make it able to deal with the HTML that is actually "out there", and
169it normally parses as closely as possible to the way the popular web
170browsers do it instead of strictly following one of the many HTML
171specifications from W3C. Where there is disagreement, there is often
172an option that you can enable to get the official behaviour.
173
174The document to be parsed may be supplied in arbitrary chunks. This
175makes on-the-fly parsing as documents are received from the network
176possible.
177
178If event driven parsing does not feel right for your application, you
179might want to use C<HTML::PullParser>. This is an C<HTML::Parser>
180subclass that allows a more conventional program structure.
181
182
183=head1 METHODS
184
185The following method is used to construct a new C<HTML::Parser> object:
186
187=over
188
189=item $p = HTML::Parser->new( %options_and_handlers )
190
191This class method creates a new C<HTML::Parser> object and
192returns it. Key/value argument pairs may be provided to assign event
193handlers or initialize parser options. The handlers and parser
194options can also be set or modified later by the method calls described below.
195
196If a top level key is in the form "<event>_h" (e.g., "text_h") then it
197assigns a handler to that event, otherwise it initializes a parser
198option. The event handler specification value must be an array
199reference. Multiple handlers may also be assigned with the 'handlers
200=> [%handlers]' option. See examples below.
201
202If new() is called without any arguments, it will create a parser that
203uses callback methods compatible with version 2 of C<HTML::Parser>.
204See the section on "version 2 compatibility" below for details.
205
206The special constructor option 'api_version => 2' can be used to
207initialize version 2 callbacks while still setting other options and
208handlers. The 'api_version => 3' option can be used if you don't want
209to set any options and don't want to fall back to v2 compatible
210mode.
211
212Examples:
213
214 $p = HTML::Parser->new(api_version => 3,
215 text_h => [ sub {...}, "dtext" ]);
216
217This creates a new parser object with a text event handler subroutine
218that receives the original text with general entities decoded.
219
220 $p = HTML::Parser->new(api_version => 3,
221 start_h => [ 'my_start', "self,tokens" ]);
222
223This creates a new parser object with a start event handler method
224that receives the $p and the tokens array.
225
226 $p = HTML::Parser->new(api_version => 3,
227 handlers => { text => [\@array, "event,text"],
228 comment => [\@array, "event,text"],
229 });
230
231This creates a new parser object that stores the event type and the
232original text in @array for text and comment events.
233
234=back
235
236The following methods feed the HTML document
237to the C<HTML::Parser> object:
238
239=over
240
241=item $p->parse( $string )
242
243Parse $string as the next chunk of the HTML document. The return
244value is normally a reference to the parser object (i.e. $p).
245Handlers invoked should not attempt to modify the $string in-place until
246$p->parse returns.
247
248If an invoked event handler aborts parsing by calling $p->eof, then
249$p->parse() will return a FALSE value.
250
251=item $p->parse( $code_ref )
252
253If a code reference is passed as the argument to be parsed, then the
254chunks to be parsed are obtained by invoking this function repeatedly.
255Parsing continues until the function returns an empty (or undefined)
256result. When this happens $p->eof is automatically signaled.
257
258Parsing will also abort if one of the event handlers calls $p->eof.
259
260The effect of this is the same as:
261
262 while (1) {
263 my $chunk = &$code_ref();
264 if (!defined($chunk) || !length($chunk)) {
265 $p->eof;
266 return $p;
267 }
268 $p->parse($chunk) || return undef;
269 }
270
271But it is more efficient as this loop runs internally in XS code.
272
273=item $p->parse_file( $file )
274
275Parse text directly from a file. The $file argument can be a
276filename, an open file handle, or a reference to an open file
277handle.
278
279If $file contains a filename and the file can't be opened, then the
280method returns an undefined value and $! tells why it failed.
281Otherwise the return value is a reference to the parser object.
282
283If a file handle is passed as the $file argument, then the file will
284normally be read until EOF, but not closed.
285
286If an invoked event handler aborts parsing by calling $p->eof,
287then $p->parse_file() may not have read the entire file.
288
289On systems with multi-byte line terminators, the values passed for the
290offset and length argspecs may be too low if parse_file() is called on
291a file handle that is not in binary mode.
292
293If a filename is passed in, then parse_file() will open the file in
294binary mode.
295
296=item $p->eof
297
298Signals the end of the HTML document. Calling the $p->eof method
299outside a handler callback will flush any remaining buffered text
300(which triggers the C<text> event if there is any remaining text).
301
302Calling $p->eof inside a handler will terminate parsing at that point
303and cause $p->parse to return a FALSE value. This also terminates
304parsing by $p->parse_file().
305
306After $p->eof has been called, the parse() and parse_file() methods
307can be invoked to feed new documents with the parser object.
308
309The return value from eof() is a reference to the parser object.
310
311=back
312
313
314Most parser options are controlled by boolean attributes.
315Each boolean attribute is enabled by calling the corresponding method
316with a TRUE argument and disabled with a FALSE argument. The
317attribute value is left unchanged if no argument is given. The return
318value from each method is the old attribute value.
319
320Methods that can be used to get and/or set parser options are:
321
322=over
323
324=item $p->attr_encoded
325
326=item $p->attr_encoded( $bool )
327
328By default, the C<attr> and C<@attr> argspecs will have general
329entities for attribute values decoded. Enabling this attribute leaves
330entities alone.
331
332=item $p->boolean_attribute_value( $val )
333
334This method sets the value reported for boolean attributes inside HTML
335start tags. By default, the name of the attribute is also used as its
336value. This affects the values reported for C<tokens> and C<attr>
337argspecs.
338
339=item $p->case_sensitive
340
341=item $p->case_sensitive( $bool )
342
343By default, tagnames and attribute names are down-cased. Enabling this
344attribute leaves them as found in the HTML source document.
345
346=item $p->closing_plaintext
347
348=item $p->closing_plaintext( $bool )
349
350By default, "plaintext" element can never be closed. Everything up to
351the end of the document is parsed in CDATA mode. This historical
352behaviour is what at least MSIE does. Enabling this attribute makes
353closing "</plaintext>" tag effective and the parsing process will resume
354after seeing this tag. This emulates gecko-based browsers.
355
356=item $p->empty_element_tags
357
358=item $p->empty_element_tags( $bool )
359
360By default, empty element tags are not recognized as such and the "/"
361before ">" is just treated like a normal name character (unless
362C<strict_names> is enabled). Enabling this attribute make
363C<HTML::Parser> recognize these tags.
364
365Empty element tags look like start tags, but end with the character
366sequence "/>" instead of ">". When recognized by C<HTML::Parser> they
367cause an artificial end event in addition to the start event. The
368C<text> for the artificial end event will be empty and the C<tokenpos>
369array will be undefined even though the the token array will have one
370element containing the tag name.
371
372=item $p->marked_sections
373
374=item $p->marked_sections( $bool )
375
376By default, section markings like <![CDATA[...]]> are treated like
377ordinary text. When this attribute is enabled section markings are
378honoured.
379
380There are currently no events associated with the marked section
381markup, but the text can be returned as C<skipped_text>.
382
383=item $p->strict_comment
384
385=item $p->strict_comment( $bool )
386
387By default, comments are terminated by the first occurrence of "-->".
388This is the behaviour of most popular browsers (like Mozilla, Opera and
389MSIE), but it is not correct according to the official HTML
390standard. Officially, you need an even number of "--" tokens before
391the closing ">" is recognized and there may not be anything but
392whitespace between an even and an odd "--".
393
394The official behaviour is enabled by enabling this attribute.
395
396Enabling of 'strict_comment' also disables recognizing these forms as
397comments:
398
399 </ comment>
400 <! comment>
401
402
403=item $p->strict_end
404
405=item $p->strict_end( $bool )
406
407By default, attributes and other junk are allowed to be present on end tags in a
408manner that emulates MSIE's behaviour.
409
410The official behaviour is enabled with this attribute. If enabled,
411only whitespace is allowed between the tagname and the final ">".
412
413=item $p->strict_names
414
415=item $p->strict_names( $bool )
416
417By default, almost anything is allowed in tag and attribute names.
418This is the behaviour of most popular browsers and allows us to parse
419some broken tags with invalid attribute values like:
420
421 <IMG SRC=newprevlstGr.gif ALT=[PREV LIST] BORDER=0>
422
423By default, "LIST]" is parsed as a boolean attribute, not as
424part of the ALT value as was clearly intended. This is also what
425Mozilla sees.
426
427The official behaviour is enabled by enabling this attribute. If
428enabled, it will cause the tag above to be reported as text
429since "LIST]" is not a legal attribute name.
430
431=item $p->unbroken_text
432
433=item $p->unbroken_text( $bool )
434
435By default, blocks of text are given to the text handler as soon as
436possible (but the parser takes care always to break text at a
437boundary between whitespace and non-whitespace so single words and
438entities can always be decoded safely). This might create breaks that
439make it hard to do transformations on the text. When this attribute is
440enabled, blocks of text are always reported in one piece. This will
441delay the text event until the following (non-text) event has been
442recognized by the parser.
443
444Note that the C<offset> argspec will give you the offset of the first
445segment of text and C<length> is the combined length of the segments.
446Since there might be ignored tags in between, these numbers can't be
447used to directly index in the original document file.
448
449=item $p->utf8_mode
450
451=item $p->utf8_mode( $bool )
452
453Enable this option when parsing raw undecoded UTF-8. This tells the
454parser that the entities expanded for strings reported by C<attr>,
455C<@attr> and C<dtext> should be expanded as decoded UTF-8 so they end
456up compatible with the surrounding text.
457
458If C<utf8_mode> is enabled then it is an error to pass strings
459containing characters with code above 255 to the parse() method, and
460the parse() method will croak if you try.
461
462Example: The Unicode character "\x{2665}" is "\xE2\x99\xA5" when UTF-8
463encoded. The character can also be represented by the entity
464"&hearts;" or "&#x2665". If we feed the parser:
465
466 $p->parse("\xE2\x99\xA5&hearts;");
467
468then C<dtext> will be reported as "\xE2\x99\xA5\x{2665}" without
469C<utf8_mode> enabled, but as "\xE2\x99\xA5\xE2\x99\xA5" when enabled.
470The later string is what you want.
471
472This option is only available with perl-5.8 or better.
473
474=item $p->xml_mode
475
476=item $p->xml_mode( $bool )
477
478Enabling this attribute changes the parser to allow some XML
479constructs. This enables the behaviour controlled by individually by
480the C<case_sensitive>, C<empty_element_tags>, C<strict_names> and
481C<xml_pic> attributes and also suppresses special treatment of
482elements that are parsed as CDATA for HTML.
483
484=item $p->xml_pic
485
486=item $p->xml_pic( $bool )
487
488By default, I<processing instructions> are terminated by ">". When
489this attribute is enabled, processing instructions are terminated by
490"?>" instead.
491
492=back
493
494As markup and text is recognized, handlers are invoked. The following
495method is used to set up handlers for different events:
496
497=over
498
499=item $p->handler( event => \&subroutine, $argspec )
500
501=item $p->handler( event => $method_name, $argspec )
502
503=item $p->handler( event => \@accum, $argspec )
504
505=item $p->handler( event => "" );
506
507=item $p->handler( event => undef );
508
509=item $p->handler( event );
510
511This method assigns a subroutine, method, or array to handle an event.
512
513Event is one of C<text>, C<start>, C<end>, C<declaration>, C<comment>,
514C<process>, C<start_document>, C<end_document> or C<default>.
515
516The C<\&subroutine> is a reference to a subroutine which is called to handle
517the event.
518
519The C<$method_name> is the name of a method of $p which is called to handle
520the event.
521
522The C<@accum> is an array that will hold the event information as
523sub-arrays.
524
525If the second argument is "", the event is ignored.
526If it is undef, the default handler is invoked for the event.
527
528The C<$argspec> is a string that describes the information to be reported
529for the event. Any requested information that does not apply to a
530specific event is passed as C<undef>. If argspec is omitted, then it
531is left unchanged.
532
533The return value from $p->handler is the old callback routine or a
534reference to the accumulator array.
535
536Any return values from handler callback routines/methods are always
537ignored. A handler callback can request parsing to be aborted by
538invoking the $p->eof method. A handler callback is not allowed to
539invoke the $p->parse() or $p->parse_file() method. An exception will
540be raised if it tries.
541
542Examples:
543
544 $p->handler(start => "start", 'self, attr, attrseq, text' );
545
546This causes the "start" method of object $p to be called for 'start' events.
547The callback signature is $p->start(\%attr, \@attr_seq, $text).
548
549 $p->handler(start => \&start, 'attr, attrseq, text' );
550
551This causes subroutine start() to be called for 'start' events.
552The callback signature is start(\%attr, \@attr_seq, $text).
553
554 $p->handler(start => \@accum, '"S", attr, attrseq, text' );
555
556This causes 'start' event information to be saved in @accum.
557The array elements will be ['S', \%attr, \@attr_seq, $text].
558
559 $p->handler(start => "");
560
561This causes 'start' events to be ignored. It also suppresses
562invocations of any default handler for start events. It is in most
563cases equivalent to $p->handler(start => sub {}), but is more
564efficient. It is different from the empty-sub-handler in that
565C<skipped_text> is not reset by it.
566
567 $p->handler(start => undef);
568
569This causes no handler to be associated with start events.
570If there is a default handler it will be invoked.
571
572=back
573
574Filters based on tags can be set up to limit the number of events
575reported. The main bottleneck during parsing is often the huge number
576of callbacks made from the parser. Applying filters can improve
577performance significantly.
578
579The following methods control filters:
580
581=over
582
583=item $p->ignore_elements( @tags )
584
585Both the C<start> event and the C<end> event as well as any events that
586would be reported in between are suppressed. The ignored elements can
587contain nested occurrences of itself. Example:
588
589 $p->ignore_elements(qw(script style));
590
591The C<script> and C<style> tags will always nest properly since their
592content is parsed in CDATA mode. For most other tags
593C<ignore_elements> must be used with caution since HTML is often not
594I<well formed>.
595
596=item $p->ignore_tags( @tags )
597
598Any C<start> and C<end> events involving any of the tags given are
599suppressed. To reset the filter (i.e. don't suppress any C<start> and
600C<end> events), call C<ignore_tags> without an argument.
601
602=item $p->report_tags( @tags )
603
604Any C<start> and C<end> events involving any of the tags I<not> given
605are suppressed. To reset the filter (i.e. report all C<start> and
606C<end> events), call C<report_tags> without an argument.
607
608=back
609
610Internally, the system has two filter lists, one for C<report_tags>
611and one for C<ignore_tags>, and both filters are applied. This
612effectively gives C<ignore_tags> precedence over C<report_tags>.
613
614Examples:
615
616 $p->ignore_tags(qw(style));
617 $p->report_tags(qw(script style));
618
619results in only C<script> events being reported.
620
621=head2 Argspec
622
623Argspec is a string containing a comma-separated list that describes
624the information reported by the event. The following argspec
625identifier names can be used:
626
627=over
628
629=item C<attr>
630
631Attr causes a reference to a hash of attribute name/value pairs to be
632passed.
633
634Boolean attributes' values are either the value set by
635$p->boolean_attribute_value, or the attribute name if no value has been
636set by $p->boolean_attribute_value.
637
638This passes undef except for C<start> events.
639
640Unless C<xml_mode> or C<case_sensitive> is enabled, the attribute
641names are forced to lower case.
642
643General entities are decoded in the attribute values and
644one layer of matching quotes enclosing the attribute values is removed.
645
646The Unicode character set is assumed for entity decoding. With Perl
647version 5.6 or earlier only the Latin-1 range is supported, and
648entities for characters outside the range 0..255 are left unchanged.
649
650=item C<@attr>
651
652Basically the same as C<attr>, but keys and values are passed as
653individual arguments and the original sequence of the attributes is
654kept. The parameters passed will be the same as the @attr calculated
655here:
656
657 @attr = map { $_ => $attr->{$_} } @$attrseq;
658
659assuming $attr and $attrseq here are the hash and array passed as the
660result of C<attr> and C<attrseq> argspecs.
661
662This passes no values for events besides C<start>.
663
664=item C<attrseq>
665
666Attrseq causes a reference to an array of attribute names to be
667passed. This can be useful if you want to walk the C<attr> hash in
668the original sequence.
669
670This passes undef except for C<start> events.
671
672Unless C<xml_mode> or C<case_sensitive> is enabled, the attribute
673names are forced to lower case.
674
675=item C<column>
676
677Column causes the column number of the start of the event to be passed.
678The first column on a line is 0.
679
680=item C<dtext>
681
682Dtext causes the decoded text to be passed. General entities are
683automatically decoded unless the event was inside a CDATA section or
684was between literal start and end tags (C<script>, C<style>,
685C<xmp>, and C<plaintext>).
686
687The Unicode character set is assumed for entity decoding. With Perl
688version 5.6 or earlier only the Latin-1 range is supported, and
689entities for characters outside the range 0..255 are left unchanged.
690
691This passes undef except for C<text> events.
692
693=item C<event>
694
695Event causes the event name to be passed.
696
697The event name is one of C<text>, C<start>, C<end>, C<declaration>,
698C<comment>, C<process>, C<start_document> or C<end_document>.
699
700=item C<is_cdata>
701
702Is_cdata causes a TRUE value to be passed if the event is inside a CDATA
703section or between literal start and end tags (C<script>,
704C<style>, C<xmp>, and C<plaintext>).
705
706if the flag is FALSE for a text event, then you should normally
707either use C<dtext> or decode the entities yourself before the text is
708processed further.
709
710=item C<length>
711
712Length causes the number of bytes of the source text of the event to
713be passed.
714
715=item C<line>
716
717Line causes the line number of the start of the event to be passed.
718The first line in the document is 1. Line counting doesn't start
719until at least one handler requests this value to be reported.
720
721=item C<offset>
722
723Offset causes the byte position in the HTML document of the start of
724the event to be passed. The first byte in the document has offset 0.
725
726=item C<offset_end>
727
728Offset_end causes the byte position in the HTML document of the end of
729the event to be passed. This is the same as C<offset> + C<length>.
730
731=item C<self>
732
733Self causes the current object to be passed to the handler. If the
734handler is a method, this must be the first element in the argspec.
735
736An alternative to passing self as an argspec is to register closures
737that capture $self by themselves as handlers. Unfortunately this
738creates circular references which prevent the HTML::Parser object
739from being garbage collected. Using the C<self> argspec avoids this
740problem.
741
742=item C<skipped_text>
743
744Skipped_text returns the concatenated text of all the events that have
745been skipped since the last time an event was reported. Events might
746be skipped because no handler is registered for them or because some
747filter applies. Skipped text also includes marked section markup,
748since there are no events that can catch it.
749
750If an C<"">-handler is registered for an event, then the text for this
751event is not included in C<skipped_text>. Skipped text both before
752and after the C<"">-event is included in the next reported
753C<skipped_text>.
754
755=item C<tag>
756
757Same as C<tagname>, but prefixed with "/" if it belongs to an C<end>
758event and "!" for a declaration. The C<tag> does not have any prefix
759for C<start> events, and is in this case identical to C<tagname>.
760
761=item C<tagname>
762
763This is the element name (or I<generic identifier> in SGML jargon) for
764start and end tags. Since HTML is case insensitive, this name is
765forced to lower case to ease string matching.
766
767Since XML is case sensitive, the tagname case is not changed when
768C<xml_mode> is enabled. The same happens if the C<case_sensitive> attribute
769is set.
770
771The declaration type of declaration elements is also passed as a tagname,
772even if that is a bit strange.
773In fact, in the current implementation tagname is
774identical to C<token0> except that the name may be forced to lower case.
775
776=item C<token0>
777
778Token0 causes the original text of the first token string to be
779passed. This should always be the same as $tokens->[0].
780
781For C<declaration> events, this is the declaration type.
782
783For C<start> and C<end> events, this is the tag name.
784
785For C<process> and non-strict C<comment> events, this is everything
786inside the tag.
787
788This passes undef if there are no tokens in the event.
789
790=item C<tokenpos>
791
792Tokenpos causes a reference to an array of token positions to be
793passed. For each string that appears in C<tokens>, this array
794contains two numbers. The first number is the offset of the start of
795the token in the original C<text> and the second number is the length
796of the token.
797
798Boolean attributes in a C<start> event will have (0,0) for the
799attribute value offset and length.
800
801This passes undef if there are no tokens in the event (e.g., C<text>)
802and for artificial C<end> events triggered by empty element tags.
803
804If you are using these offsets and lengths to modify C<text>, you
805should either work from right to left, or be very careful to calculate
806the changes to the offsets.
807
808=item C<tokens>
809
810Tokens causes a reference to an array of token strings to be passed.
811The strings are exactly as they were found in the original text,
812no decoding or case changes are applied.
813
814For C<declaration> events, the array contains each word, comment, and
815delimited string starting with the declaration type.
816
817For C<comment> events, this contains each sub-comment. If
818$p->strict_comments is disabled, there will be only one sub-comment.
819
820For C<start> events, this contains the original tag name followed by
821the attribute name/value pairs. The values of boolean attributes will
822be either the value set by $p->boolean_attribute_value, or the
823attribute name if no value has been set by
824$p->boolean_attribute_value.
825
826For C<end> events, this contains the original tag name (always one token).
827
828For C<process> events, this contains the process instructions (always one
829token).
830
831This passes C<undef> for C<text> events.
832
833=item C<text>
834
835Text causes the source text (including markup element delimiters) to be
836passed.
837
838=item C<undef>
839
840Pass an undefined value. Useful as padding where the same handler
841routine is registered for multiple events.
842
843=item C<'...'>
844
845A literal string of 0 to 255 characters enclosed
846in single (') or double (") quotes is passed as entered.
847
848=back
849
850The whole argspec string can be wrapped up in C<'@{...}'> to signal
851that the resulting event array should be flattened. This only makes a
852difference if an array reference is used as the handler target.
853Consider this example:
854
855 $p->handler(text => [], 'text');
856 $p->handler(text => [], '@{text}']);
857
858With two text events; C<"foo">, C<"bar">; then the first example will end
859up with [["foo"], ["bar"]] and the second with ["foo", "bar"] in
860the handler target array.
861
862
863=head2 Events
864
865Handlers for the following events can be registered:
866
867=over
868
869=item C<comment>
870
871This event is triggered when a markup comment is recognized.
872
873Example:
874
875 <!-- This is a comment -- -- So is this -->
876
877=item C<declaration>
878
879This event is triggered when a I<markup declaration> is recognized.
880
881For typical HTML documents, the only declaration you are
882likely to find is <!DOCTYPE ...>.
883
884Example:
885
886 <!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN"
887 "http://www.w3.org/TR/html40/strict.dtd">
888
889DTDs inside <!DOCTYPE ...> will confuse HTML::Parser.
890
891=item C<default>
892
893This event is triggered for events that do not have a specific
894handler. You can set up a handler for this event to catch stuff you
895did not want to catch explicitly.
896
897=item C<end>
898
899This event is triggered when an end tag is recognized.
900
901Example:
902
903 </A>
904
905=item C<end_document>
906
907This event is triggered when $p->eof is called and after any remaining
908text is flushed. There is no document text associated with this event.
909
910=item C<process>
911
912This event is triggered when a processing instructions markup is
913recognized.
914
915The format and content of processing instructions are system and
916application dependent.
917
918Examples:
919
920 <? HTML processing instructions >
921 <? XML processing instructions ?>
922
923=item C<start>
924
925This event is triggered when a start tag is recognized.
926
927Example:
928
929 <A HREF="http://www.perl.com/">
930
931=item C<start_document>
932
933This event is triggered before any other events for a new document. A
934handler for it can be used to initialize stuff. There is no document
935text associated with this event.
936
937=item C<text>
938
939This event is triggered when plain text (characters) is recognized.
940The text may contain multiple lines. A sequence of text may be broken
941between several text events unless $p->unbroken_text is enabled.
942
943The parser will make sure that it does not break a word or a sequence
944of whitespace between two text events.
945
946=back
947
948=head2 Unicode
949
950The C<HTML::Parser> can parse Unicode strings when running under
951perl-5.8 or better. If Unicode is passed to $p->parse() then chunks
952of Unicode will be reported to the handlers. The offset and length
953argspecs will also report their position in terms of characters.
954
955It is safe to parse raw undecoded UTF-8 if you either avoid decoding
956entities and make sure to not use I<argspecs> that do, or enable the
957C<utf8_mode> for the parser. Parsing of undecoded UTF-8 might be
958useful when parsing from a file where you need the reported offsets
959and lengths to match the byte offsets in the file.
960
961If a filename is passed to $p->parse_file() then the file will be read
962in binary mode. This will be fine if the file contains only ASCII or
963Latin-1 characters. If the file contains UTF-8 encoded text then care
964must be taken when decoding entities as described in the previous
965paragraph, but better is to open the file with the UTF-8 layer so that
966it is decoded properly:
967
968 open(my $fh, "<:utf8", "index.html") || die "...: $!";
969 $p->parse_file($fh);
970
971If the file contains text encoded in a charset besides ASCII, Latin-1
972or UTF-8 then decoding will always be needed.
973
974=head1 VERSION 2 COMPATIBILITY
975
976When an C<HTML::Parser> object is constructed with no arguments, a set
977of handlers is automatically provided that is compatible with the old
978HTML::Parser version 2 callback methods.
979
980This is equivalent to the following method calls:
981
982 $p->handler(start => "start", "self, tagname, attr, attrseq, text");
983 $p->handler(end => "end", "self, tagname, text");
984 $p->handler(text => "text", "self, text, is_cdata");
985 $p->handler(process => "process", "self, token0, text");
986 $p->handler(comment =>
987 sub {
988 my($self, $tokens) = @_;
989 for (@$tokens) {$self->comment($_);}},
990 "self, tokens");
991 $p->handler(declaration =>
992 sub {
993 my $self = shift;
994 $self->declaration(substr($_[0], 2, -1));},
995 "self, text");
996
997Setting up these handlers can also be requested with the "api_version =>
9982" constructor option.
999
1000=head1 SUBCLASSING
1001
1002The C<HTML::Parser> class is subclassable. Parser objects are plain
1003hashes and C<HTML::Parser> reserves only hash keys that start with
1004"_hparser". The parser state can be set up by invoking the init()
1005method, which takes the same arguments as new().
1006
1007=head1 EXAMPLES
1008
1009The first simple example shows how you might strip out comments from
1010an HTML document. We achieve this by setting up a comment handler that
1011does nothing and a default handler that will print out anything else:
1012
1013 use HTML::Parser;
1014 HTML::Parser->new(default_h => [sub { print shift }, 'text'],
1015 comment_h => [""],
1016 )->parse_file(shift || die) || die $!;
1017
1018An alternative implementation is:
1019
1020 use HTML::Parser;
1021 HTML::Parser->new(end_document_h => [sub { print shift },
1022 'skipped_text'],
1023 comment_h => [""],
1024 )->parse_file(shift || die) || die $!;
1025
1026This will in most cases be much more efficient since only a single
1027callback will be made.
1028
1029The next example prints out the text that is inside the <title>
1030element of an HTML document. Here we start by setting up a start
1031handler. When it sees the title start tag it enables a text handler
1032that prints any text found and an end handler that will terminate
1033parsing as soon as the title end tag is seen:
1034
1035 use HTML::Parser ();
1036
1037 sub start_handler
1038 {
1039 return if shift ne "title";
1040 my $self = shift;
1041 $self->handler(text => sub { print shift }, "dtext");
1042 $self->handler(end => sub { shift->eof if shift eq "title"; },
1043 "tagname,self");
1044 }
1045
1046 my $p = HTML::Parser->new(api_version => 3);
1047 $p->handler( start => \&start_handler, "tagname,self");
1048 $p->parse_file(shift || die) || die $!;
1049 print "\n";
1050
1051More examples are found in the F<eg/> directory of the C<HTML-Parser>
1052distribution: the program C<hrefsub> shows how you can edit all links
1053found in a document; the program C<htextsub> shows how to edit the text only; the
1054program C<hstrip> shows how you can strip out certain tags/elements
1055and/or attributes; and the program C<htext> show how to obtain the
1056plain text, but not any script/style content.
1057
1058You can browse the F<eg/> directory online from the I<[Browse]> link on
1059the http://search.cpan.org/~gaas/HTML-Parser/ page.
1060
1061=head1 BUGS
1062
1063The <style> and <script> sections do not end with the first "</", but
1064need the complete corresponding end tag. The standard behaviour is
1065not really practical.
1066
1067When the I<strict_comment> option is enabled, we still recognize
1068comments where there is something other than whitespace between even
1069and odd "--" markers.
1070
1071Once $p->boolean_attribute_value has been set, there is no way to
1072restore the default behaviour.
1073
1074There is currently no way to get both quote characters
1075into the same literal argspec.
1076
1077Empty tags, e.g. "<>" and "</>", are not recognized. SGML allows them
1078to repeat the previous start tag or close the previous start tag
1079respectively.
1080
1081NET tags, e.g. "code/.../" are not recognized. This is SGML
1082shorthand for "<code>...</code>".
1083
1084Unclosed start or end tags, e.g. "<tt<b>...</b</tt>" are not
1085recognized.
1086
1087=head1 DIAGNOSTICS
1088
1089The following messages may be produced by HTML::Parser. The notation
1090in this listing is the same as used in L<perldiag>:
1091
1092=over
1093
1094=item Not a reference to a hash
1095
1096(F) The object blessed into or subclassed from HTML::Parser is not a
1097hash as required by the HTML::Parser methods.
1098
1099=item Bad signature in parser state object at %p
1100
1101(F) The _hparser_xs_state element does not refer to a valid state structure.
1102Something must have changed the internal value
1103stored in this hash element, or the memory has been overwritten.
1104
1105=item _hparser_xs_state element is not a reference
1106
1107(F) The _hparser_xs_state element has been destroyed.
1108
1109=item Can't find '_hparser_xs_state' element in HTML::Parser hash
1110
1111(F) The _hparser_xs_state element is missing from the parser hash.
1112It was either deleted, or not created when the object was created.
1113
1114=item API version %s not supported by HTML::Parser %s
1115
1116(F) The constructor option 'api_version' with an argument greater than
1117or equal to 4 is reserved for future extensions.
1118
1119=item Bad constructor option '%s'
1120
1121(F) An unknown constructor option key was passed to the new() or
1122init() methods.
1123
1124=item Parse loop not allowed
1125
1126(F) A handler invoked the parse() or parse_file() method.
1127This is not permitted.
1128
1129=item marked sections not supported
1130
1131(F) The $p->marked_sections() method was invoked in a HTML::Parser
1132module that was compiled without support for marked sections.
1133
1134=item Unknown boolean attribute (%d)
1135
1136(F) Something is wrong with the internal logic that set up aliases for
1137boolean attributes.
1138
1139=item Only code or array references allowed as handler
1140
1141(F) The second argument for $p->handler must be either a subroutine
1142reference, then name of a subroutine or method, or a reference to an
1143array.
1144
1145=item No handler for %s events
1146
1147(F) The first argument to $p->handler must be a valid event name; i.e. one
1148of "start", "end", "text", "process", "declaration" or "comment".
1149
1150=item Unrecognized identifier %s in argspec
1151
1152(F) The identifier is not a known argspec name.
1153Use one of the names mentioned in the argspec section above.
1154
1155=item Literal string is longer than 255 chars in argspec
1156
1157(F) The current implementation limits the length of literals in
1158an argspec to 255 characters. Make the literal shorter.
1159
1160=item Backslash reserved for literal string in argspec
1161
1162(F) The backslash character "\" is not allowed in argspec literals.
1163It is reserved to permit quoting inside a literal in a later version.
1164
1165=item Unterminated literal string in argspec
1166
1167(F) The terminating quote character for a literal was not found.
1168
1169=item Bad argspec (%s)
1170
1171(F) Only identifier names, literals, spaces and commas
1172are allowed in argspecs.
1173
1174=item Missing comma separator in argspec
1175
1176(F) Identifiers in an argspec must be separated with ",".
1177
1178=item Parsing of undecoded UTF-8 will give garbage when decoding entities
1179
1180(W) The first chunk parsed appears to contain undecoded UTF-8 and one
1181or more argspecs that decode entities are used for the callback
1182handlers.
1183
1184The result of decoding will be a mix of encoded and decoded characters
1185for any entities that expand to characters with code above 127. This
1186is not a good thing.
1187
1188The solution is to use the Encode::encode_utf8() on the data before
1189feeding it to the $p->parse(). For $p->parse_file() pass a file that
1190has been opened in ":utf8" mode.
1191
1192The parser can process raw undecoded UTF-8 sanely if the C<utf8_mode>
1193is enabled or if the "attr", "@attr" or "dtext" argspecs is avoided.
1194
1195=item Parsing string decoded with wrong endianess
1196
1197(W) The first character in the document is U+FFFE. This is not a
1198legal Unicode character but a byte swapped BOM. The result of parsing
1199will likely be garbage.
1200
1201=item Parsing of undecoded UTF-32
1202
1203(W) The parser found the Unicode UTF-32 BOM signature at the start
1204of the document. The result of parsing will likely be garbage.
1205
1206=item Parsing of undecoded UTF-16
1207
1208(W) The parser found the Unicode UTF-16 BOM signature at the start of
1209the document. The result of parsing will likely be garbage.
1210
1211=back
1212
1213=head1 SEE ALSO
1214
1215L<HTML::Entities>, L<HTML::PullParser>, L<HTML::TokeParser>, L<HTML::HeadParser>,
1216L<HTML::LinkExtor>, L<HTML::Form>
1217
1218L<HTML::TreeBuilder> (part of the I<HTML-Tree> distribution)
1219
1220http://www.w3.org/TR/html4
1221
1222More information about marked sections and processing instructions may
1223be found at C<http://www.sgml.u-net.com/book/sgml-8.htm>.
1224
1225=head1 COPYRIGHT
1226
1227 Copyright 1996-2007 Gisle Aas. All rights reserved.
1228 Copyright 1999-2000 Michael A. Chase. All rights reserved.
1229
1230This library is free software; you can redistribute it and/or
1231modify it under the same terms as Perl itself.
1232
1233=cut
# spent 6.65ms within HTML::Parser::CORE:match which was called 922 times, avg 7µs/call: # 922 times (6.65ms+0s) by HTML::Parser::init at line 72 of HTML/Parser.pm, avg 7µs/call
sub HTML::Parser::CORE:match; # xsub
# spent 7.42ms within HTML::Parser::_alloc_pstate which was called 461 times, avg 16µs/call: # 461 times (7.42ms+0s) by HTML::Parser::init at line 30 of HTML/Parser.pm, avg 16µs/call
sub HTML::Parser::_alloc_pstate; # xsub
# spent 48µs within HTML::Parser::eof which was called 7 times, avg 7µs/call: # 7 times (48µs+0s) by HTML::HeadParser::text at line 216 of HTML/HeadParser.pm, avg 7µs/call
sub HTML::Parser::eof; # xsub
# spent 25.5ms within HTML::Parser::handler which was called 2766 times, avg 9µs/call: # 461 times (5.89ms+0s) by HTML::Parser::init at line 42 of HTML/Parser.pm, avg 13µs/call # 461 times (4.47ms+0s) by HTML::Parser::init at line 45 of HTML/Parser.pm, avg 10µs/call # 461 times (4.13ms+0s) by HTML::Parser::init at line 43 of HTML/Parser.pm, avg 9µs/call # 461 times (3.98ms+0s) by HTML::Parser::init at line 44 of HTML/Parser.pm, avg 9µs/call # 461 times (3.52ms+0s) by HTML::Parser::init at line 54 of HTML/Parser.pm, avg 8µs/call # 461 times (3.48ms+0s) by HTML::Parser::init at line 60 of HTML/Parser.pm, avg 8µs/call
sub HTML::Parser::handler; # xsub
# spent 5.15ms within HTML::Parser::ignore_elements which was called 461 times, avg 11µs/call: # 461 times (5.15ms+0s) by HTML::Parser::init at line 80 of HTML/Parser.pm, avg 11µs/call
sub HTML::Parser::ignore_elements; # xsub
# spent 986µs (283+703) within HTML::Parser::parse which was called 7 times, avg 141µs/call: # 7 times (283µs+703µs) by LWP::Protocol::collect at line 114 of LWP/Protocol.pm, avg 141µs/call
sub HTML::Parser::parse; # xsub