PSP::HTML::Filter - Filter HTML text through the parser
This module is deprecated. PSP::HTML::Parser
now provides the
functionally of PSP::HTML::Filter
much more efficiently with the the
default
handler.
require PSP::HTML::Filter; $p = PSP::HTML::Filter->new->parse_file("index.html");
PSP::HTML::Filter
is an HTML parser that by default prints the
original text of each HTML element (a slow version of cat(1) basically).
The callback methods may be overridden to modify the filtering for some
HTML elements and you can override output() method which is called to
print the HTML text.
PSP::HTML::Filter
is a subclass of PSP::HTML::Parser
. This means that
the document should be given to the parser by calling the $p->parse()
or $p->parse_file() methods.
The first example is a filter that will remove all comments from an HTML file. This is achieved by simply overriding the comment method to do nothing.
package CommentStripper; require PSP::HTML::Filter; @ISA=qw(PSP::HTML::Filter); sub comment { } # ignore comments
The second example shows a filter that will remove any <TABLE>s found in the HTML file. We specialize the start() and end() methods to count table tags and then make output not happen when inside a table.
package TableStripper; require PSP::HTML::Filter; @ISA=qw(PSP::HTML::Filter); sub start { my $self = shift; $self->{table_seen}++ if $_[0] eq "table"; $self->SUPER::start(@_); }
sub end { my $self = shift; $self->SUPER::end(@_); $self->{table_seen}-- if $_[0] eq "table"; }
sub output { my $self = shift; unless ($self->{table_seen}) { $self->SUPER::output(@_); } }
If you want to collect the parsed text internally you might want to do something like this:
package FilterIntoString; require PSP::HTML::Filter; @ISA=qw(PSP::HTML::Filter); sub output { push(@{$_[0]->{fhtml}}, $_[1]) } sub filtered_html { join("", @{$_[0]->{fhtml}}) }
Copyright 1997-1999 Gisle Aas.
This library is free software; you can redistribute it and/or modify it under the same terms as Perl itself.