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HTML::Parser - HTML parser class
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);
Objects of the HTML::Parser
class will recognize markup and
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.
HTML::Parser
is not a generic SGML parser. We have tried to
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 HTML::PullParser
. This is an HTML::Parser
subclass that allows a more conventional program structure.
The following method is used to construct a new HTML::Parser
object:
This class method creates a new HTML::Parser
object and
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 ``<event>_h'' (e.g., ``text_h'') then it 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 HTML::Parser
.
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.
The following methods feed the HTML document
to the HTML::Parser
object:
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.
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 signaled.
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.
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.
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 text
event if there is any remaining text).
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.
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:
By default, the attr
and @attr
argspecs will have general
entities for attribute values decoded. Enabling this attribute leaves
entities alone.
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 tokens
and attr
argspecs.
By default, tagnames and attribute names are down-cased. Enabling this attribute leaves them as found in the HTML source document.
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 ``</plaintext>'' tag effective and the parsing process will resume after seeing this tag. This emulates gecko-based browsers.
By default, empty element tags are not recognized as such and the ``/''
before ``>'' is just treated like a normal name character (unless
strict_names
is enabled). Enabling this attribute make
HTML::Parser
recognize these tags.
Empty element tags look like start tags, but end with the character
sequence ``/>'' instead of ``>''. When recognized by HTML::Parser
they
cause an artificial end event in addition to the start event. The
text
for the artificial end event will be empty and the tokenpos
array will be undefined even though the the token array will have one
element containing the tag name.
By default, section markings like <![CDATA[...]]> 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 skipped_text
.
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:
</ comment> <! comment>
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 ``>''.
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:
<IMG SRC=newprevlstGr.gif ALT=[PREV LIST] BORDER=0>
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.
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 offset
argspec will give you the offset of the first
segment of text and length
is the combined length of the segments.
Since there might be ignored tags in between, these numbers can't be
used to directly index in the original document file.
Enable this option when parsing raw undecoded UTF-8. This tells the
parser that the entities expanded for strings reported by attr
,
@attr
and dtext
should be expanded as decoded UTF-8 so they end
up compatible with the surrounding text.
If utf8_mode
is enabled then it is an error to pass strings
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 dtext
will be reported as ``\xE2\x99\xA5\x{2665}'' without
utf8_mode
enabled, but as ``\xE2\x99\xA5\xE2\x99\xA5'' when enabled.
The later string is what you want.
This option is only available with perl-5.8 or better.
Enabling this attribute changes the parser to allow some XML
constructs. This enables the behaviour controlled by individually by
the case_sensitive
, empty_element_tags
, strict_names
and
xml_pic
attributes and also suppresses special treatment of
elements that are parsed as CDATA for HTML.
By default, processing instructions are terminated by ``>''. When this attribute is enabled, processing instructions are terminated by ``?>'' instead.
As markup and text is recognized, handlers are invoked. The following method is used to set up handlers for different events:
This method assigns a subroutine, method, or array to handle an event.
Event is one of text
, start
, end
, declaration
, comment
,
process
, start_document
, end_document
or default
.
The \&subroutine
is a reference to a subroutine which is called to handle
the event.
The $method_name
is the name of a method of $p which is called to handle
the event.
The @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 $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 undef
. If argspec is omitted, then it
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
skipped_text
is not reset by it.
$p->handler(start => undef);
This causes no handler to be associated with start events. If there is a default handler it will be invoked.
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:
Both the start
event and the end
event as well as any events that
would be reported in between are suppressed. The ignored elements can
contain nested occurrences of itself. Example:
$p->ignore_elements(qw(script style));
The script
and style
tags will always nest properly since their
content is parsed in CDATA mode. For most other tags
ignore_elements
must be used with caution since HTML is often not
well formed.
Any start
and end
events involving any of the tags given are
suppressed. To reset the filter (i.e. don't suppress any start
and
end
events), call ignore_tags
without an argument.
Any start
and end
events involving any of the tags not given
are suppressed. To reset the filter (i.e. report all start
and
end
events), call report_tags
without an argument.
Internally, the system has two filter lists, one for report_tags
and one for ignore_tags
, and both filters are applied. This
effectively gives ignore_tags
precedence over report_tags
.
Examples:
$p->ignore_tags(qw(style)); $p->report_tags(qw(script style));
results in only script
events being reported.
Argspec is a string containing a comma-separated list that describes the information reported by the event. The following argspec identifier names can be used:
attr
Attr causes a reference to a hash of attribute name/value pairs to be passed.
Boolean attributes' values are either the value set by $p->boolean_attribute_value, or the attribute name if no value has been set by $p->boolean_attribute_value.
This passes undef except for start
events.
Unless xml_mode
or case_sensitive
is enabled, the attribute
names are forced to lower case.
General entities are decoded in the attribute values and one layer of matching quotes enclosing the attribute values is removed.
The Unicode character set is assumed for entity decoding. With Perl version 5.6 or earlier only the Latin-1 range is supported, and entities for characters outside the range 0..255 are left unchanged.
@attr
Basically the same as attr
, but keys and values are passed as
individual arguments and the original sequence of the attributes is
kept. The parameters passed will be the same as the @attr calculated
here:
@attr = map { $_ => $attr->{$_} } @$attrseq;
assuming $attr and $attrseq here are the hash and array passed as the
result of attr
and attrseq
argspecs.
This passes no values for events besides start
.
attrseq
Attrseq causes a reference to an array of attribute names to be
passed. This can be useful if you want to walk the attr
hash in
the original sequence.
This passes undef except for start
events.
Unless xml_mode
or case_sensitive
is enabled, the attribute
names are forced to lower case.
column
Column causes the column number of the start of the event to be passed. The first column on a line is 0.
dtext
Dtext causes the decoded text to be passed. General entities are
automatically decoded unless the event was inside a CDATA section or
was between literal start and end tags (script
, style
,
xmp
, and plaintext
).
The Unicode character set is assumed for entity decoding. With Perl version 5.6 or earlier only the Latin-1 range is supported, and entities for characters outside the range 0..255 are left unchanged.
This passes undef except for text
events.
event
Event causes the event name to be passed.
The event name is one of text
, start
, end
, declaration
,
comment
, process
, start_document
or end_document
.
is_cdata
Is_cdata causes a TRUE value to be passed if the event is inside a CDATA
section or between literal start and end tags (script
,
style
, xmp
, and plaintext
).
if the flag is FALSE for a text event, then you should normally
either use dtext
or decode the entities yourself before the text is
processed further.
length
Length causes the number of bytes of the source text of the event to be passed.
line
Line causes the line number of the start of the event to be passed. The first line in the document is 1. Line counting doesn't start until at least one handler requests this value to be reported.
offset
Offset causes the byte position in the HTML document of the start of the event to be passed. The first byte in the document has offset 0.
offset_end
Offset_end causes the byte position in the HTML document of the end of
the event to be passed. This is the same as offset
+ length
.
self
Self causes the current object to be passed to the handler. If the handler is a method, this must be the first element in the argspec.
An alternative to passing self as an argspec is to register closures
that capture $self by themselves as handlers. Unfortunately this
creates circular references which prevent the HTML::Parser object
from being garbage collected. Using the self
argspec avoids this
problem.
skipped_text
Skipped_text returns the concatenated text of all the events that have been skipped since the last time an event was reported. Events might be skipped because no handler is registered for them or because some filter applies. Skipped text also includes marked section markup, since there are no events that can catch it.
If an ""
-handler is registered for an event, then the text for this
event is not included in skipped_text
. Skipped text both before
and after the ""
-event is included in the next reported
skipped_text
.
tag
Same as tagname
, but prefixed with ``/'' if it belongs to an end
event and ``!'' for a declaration. The tag
does not have any prefix
for start
events, and is in this case identical to tagname
.
tagname
This is the element name (or generic identifier in SGML jargon) for start and end tags. Since HTML is case insensitive, this name is forced to lower case to ease string matching.
Since XML is case sensitive, the tagname case is not changed when
xml_mode
is enabled. The same happens if the case_sensitive
attribute
is set.
The declaration type of declaration elements is also passed as a tagname,
even if that is a bit strange.
In fact, in the current implementation tagname is
identical to token0
except that the name may be forced to lower case.
token0
Token0 causes the original text of the first token string to be passed. This should always be the same as $tokens->[0].
For declaration
events, this is the declaration type.
For process
and non-strict comment
events, this is everything
inside the tag.
This passes undef if there are no tokens in the event.
tokenpos
Tokenpos causes a reference to an array of token positions to be
passed. For each string that appears in tokens
, this array
contains two numbers. The first number is the offset of the start of
the token in the original text
and the second number is the length
of the token.
Boolean attributes in a start
event will have (0,0) for the
attribute value offset and length.
This passes undef if there are no tokens in the event (e.g., text
)
and for artificial end
events triggered by empty element tags.
If you are using these offsets and lengths to modify text
, you
should either work from right to left, or be very careful to calculate
the changes to the offsets.
tokens
Tokens causes a reference to an array of token strings to be passed. The strings are exactly as they were found in the original text, no decoding or case changes are applied.
For declaration
events, the array contains each word, comment, and
delimited string starting with the declaration type.
For comment
events, this contains each sub-comment. If
$p->strict_comments is disabled, there will be only one sub-comment.
For start
events, this contains the original tag name followed by
the attribute name/value pairs. The values of boolean attributes will
be either the value set by $p->boolean_attribute_value, or the
attribute name if no value has been set by
$p->boolean_attribute_value.
For end
events, this contains the original tag name (always one token).
For process
events, this contains the process instructions (always one
token).
text
Text causes the source text (including markup element delimiters) to be passed.
undef
Pass an undefined value. Useful as padding where the same handler routine is registered for multiple events.
'...'
A literal string of 0 to 255 characters enclosed in single (') or double (``) quotes is passed as entered.
The whole argspec string can be wrapped up in '@{...}'
to signal
that the resulting event array should be flattened. This only makes a
difference if an array reference is used as the handler target.
Consider this example:
$p->handler(text => [], 'text'); $p->handler(text => [], '@{text}']);
With two text events; "foo"
, "bar"
; then the first example will end
up with [[``foo''], [``bar'']] and the second with [``foo'', ``bar''] in
the handler target array.
Handlers for the following events can be registered:
comment
This event is triggered when a markup comment is recognized.
Example:
<!-- This is a comment -- -- So is this -->
declaration
This event is triggered when a markup declaration is recognized.
For typical HTML documents, the only declaration you are likely to find is <!DOCTYPE ...>.
Example:
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN" "http://www.w3.org/TR/html40/strict.dtd">
DTDs inside <!DOCTYPE ...> will confuse HTML::Parser.
default
This event is triggered for events that do not have a specific handler. You can set up a handler for this event to catch stuff you did not want to catch explicitly.
end
This event is triggered when an end tag is recognized.
Example:
</A>
end_document
This event is triggered when $p->eof is called and after any remaining text is flushed. There is no document text associated with this event.
process
This event is triggered when a processing instructions markup is recognized.
The format and content of processing instructions are system and application dependent.
Examples:
<? HTML processing instructions > <? XML processing instructions ?>
start
This event is triggered when a start tag is recognized.
Example:
<A HREF="http://www.perl.com/">
start_document
This event is triggered before any other events for a new document. A handler for it can be used to initialize stuff. There is no document text associated with this event.
text
This event is triggered when plain text (characters) is recognized. The text may contain multiple lines. A sequence of text may be broken between several text events unless $p->unbroken_text is enabled.
The parser will make sure that it does not break a word or a sequence of whitespace between two text events.
The HTML::Parser
can parse Unicode strings when running under
perl-5.8 or better. If Unicode is passed to $p->parse()
then chunks
of Unicode will be reported to the handlers. The offset and length
argspecs will also report their position in terms of characters.
It is safe to parse raw undecoded UTF-8 if you either avoid decoding
entities and make sure to not use argspecs that do, or enable the
utf8_mode
for the parser. Parsing of undecoded UTF-8 might be
useful when parsing from a file where you need the reported offsets
and lengths to match the byte offsets in the file.
If a filename is passed to $p->parse_file()
then the file will be read
in binary mode. This will be fine if the file contains only ASCII or
Latin-1 characters. If the file contains UTF-8 encoded text then care
must be taken when decoding entities as described in the previous
paragraph, but better is to open the file with the UTF-8 layer so that
it is decoded properly:
open(my $fh, "<:utf8", "index.html") || die "...: $!"; $p->parse_file($fh);
If the file contains text encoded in a charset besides ASCII, Latin-1 or UTF-8 then decoding will always be needed.
When an HTML::Parser
object is constructed with no arguments, a set
of handlers is automatically provided that is compatible with the old
HTML::Parser version 2 callback methods.
This is equivalent to the following method calls:
$p->handler(start => "start", "self, tagname, attr, attrseq, text"); $p->handler(end => "end", "self, tagname, text"); $p->handler(text => "text", "self, text, is_cdata"); $p->handler(process => "process", "self, token0, text"); $p->handler(comment => sub { my($self, $tokens) = @_; for (@$tokens) {$self->comment($_);}}, "self, tokens"); $p->handler(declaration => sub { my $self = shift; $self->declaration(substr($_[0], 2, -1));}, "self, text");
Setting up these handlers can also be requested with the ``api_version => 2'' constructor option.
The HTML::Parser
class is subclassable. Parser objects are plain
hashes and HTML::Parser
reserves only hash keys that start with
``_hparser''. The parser state can be set up by invoking the init()
method, which takes the same arguments as new().
The first simple example shows how you might strip out comments from an HTML document. We achieve this by setting up a comment handler that does nothing and a default handler that will print out anything else:
use HTML::Parser; HTML::Parser->new(default_h => [sub { print shift }, 'text'], comment_h => [""], )->parse_file(shift || die) || die $!;
An alternative implementation is:
use HTML::Parser; HTML::Parser->new(end_document_h => [sub { print shift }, 'skipped_text'], comment_h => [""], )->parse_file(shift || die) || die $!;
This will in most cases be much more efficient since only a single callback will be made.
The next example prints out the text that is inside the <title> element of an HTML document. Here we start by setting up a start handler. When it sees the title start tag it enables a text handler that prints any text found and an end handler that will terminate parsing as soon as the title end tag is seen:
use HTML::Parser ();
sub start_handler { return if shift ne "title"; my $self = shift; $self->handler(text => sub { print shift }, "dtext"); $self->handler(end => sub { shift->eof if shift eq "title"; }, "tagname,self"); }
my $p = HTML::Parser->new(api_version => 3); $p->handler( start => \&start_handler, "tagname,self"); $p->parse_file(shift || die) || die $!; print "\n";
More examples are found in the eg/ directory of the HTML-Parser
distribution: the program hrefsub
shows how you can edit all links
found in a document; the program htextsub
shows how to edit the text only; the
program hstrip
shows how you can strip out certain tags/elements
and/or attributes; and the program htext
show how to obtain the
plain text, but not any script/style content.
You can browse the eg/ directory online from the [Browse] link on the http://search.cpan.org/~gaas/HTML-Parser/ page.
The <style> and <script> sections do not end with the first ``</'', but need the complete corresponding end tag. The standard behaviour is not really practical.
When the strict_comment option is enabled, we still recognize comments where there is something other than whitespace between even and odd ``--'' markers.
Once $p->boolean_attribute_value has been set, there is no way to restore the default behaviour.
There is currently no way to get both quote characters into the same literal argspec.
Empty tags, e.g. ``<>'' and ``</>'', are not recognized. SGML allows them to repeat the previous start tag or close the previous start tag respectively.
NET tags, e.g. ``code/.../'' are not recognized. This is SGML shorthand for ``<code>...</code>''.
Unclosed start or end tags, e.g. ``<tt<b>...</b</tt>'' are not recognized.
The following messages may be produced by HTML::Parser. The notation in this listing is the same as used in the perldiag manpage:
(F) The object blessed into or subclassed from HTML::Parser is not a hash as required by the HTML::Parser methods.
(F) The _hparser_xs_state element does not refer to a valid state structure. Something must have changed the internal value stored in this hash element, or the memory has been overwritten.
(F) The _hparser_xs_state element has been destroyed.
(F) The _hparser_xs_state element is missing from the parser hash. It was either deleted, or not created when the object was created.
(F) The constructor option 'api_version' with an argument greater than or equal to 4 is reserved for future extensions.
(F) An unknown constructor option key was passed to the new()
or
init()
methods.
(F) A handler invoked the parse()
or parse_file()
method.
This is not permitted.
(F) The $p->marked_sections()
method was invoked in a HTML::Parser
module that was compiled without support for marked sections.
(F) Something is wrong with the internal logic that set up aliases for boolean attributes.
(F) The second argument for $p->handler must be either a subroutine reference, then name of a subroutine or method, or a reference to an array.
(F) The first argument to $p->handler must be a valid event name; i.e. one of ``start'', ``end'', ``text'', ``process'', ``declaration'' or ``comment''.
(F) The identifier is not a known argspec name. Use one of the names mentioned in the argspec section above.
(F) The current implementation limits the length of literals in an argspec to 255 characters. Make the literal shorter.
(F) The backslash character ``\'' is not allowed in argspec literals. It is reserved to permit quoting inside a literal in a later version.
(F) The terminating quote character for a literal was not found.
(F) Only identifier names, literals, spaces and commas are allowed in argspecs.
(F) Identifiers in an argspec must be separated with ``,''.
(W) The first chunk parsed appears to contain undecoded UTF-8 and one or more argspecs that decode entities are used for the callback handlers.
The result of decoding will be a mix of encoded and decoded characters for any entities that expand to characters with code above 127. This is not a good thing.
The solution is to use the Encode::encode_utf8() on the data before
feeding it to the $p->parse(). For $p->parse_file()
pass a file that
has been opened in ``:utf8'' mode.
The parser can process raw undecoded UTF-8 sanely if the utf8_mode
is enabled or if the ``attr'', ``@attr'' or ``dtext'' argspecs is avoided.
(W) The first character in the document is U+FFFE. This is not a legal Unicode character but a byte swapped BOM. The result of parsing will likely be garbage.
(W) The parser found the Unicode UTF-32 BOM signature at the start of the document. The result of parsing will likely be garbage.
(W) The parser found the Unicode UTF-16 BOM signature at the start of the document. The result of parsing will likely be garbage.
the HTML::Entities manpage, the HTML::PullParser manpage, the HTML::TokeParser manpage, the HTML::HeadParser manpage, the HTML::LinkExtor manpage, the HTML::Form manpage
the HTML::TreeBuilder manpage (part of the HTML-Tree distribution)
More information about marked sections and processing instructions may
be found at http://www.sgml.u-net.com/book/sgml-8.htm
.
Copyright 1996-2007 Gisle Aas. All rights reserved. Copyright 1999-2000 Michael A. Chase. All rights reserved.
This library is free software; you can redistribute it and/or modify it under the same terms as Perl itself.