# NAME HTML::Filter::Callbacks - modify HTML with callbacks # SYNOPSIS use HTML::Filter::Callbacks; # Case 1: remove script tags my $filter = HTML::Filter::Callbacks->new; $filter->add_callbacks( script => { start => sub { shift->remove_text_and_tag }, end => sub { shift->remove_text_and_tag }, }, ); my $new_html = $filter->process($html); # Case 2: remove on_* attributes my $filter = HTML::Filter::Callbacks->new; $filter->add_callbacks( '*' => { start => sub { shift->remove_attr(qr/^on_/) }, }, ); my $new_html = $filter->process($html); # Case 3: replace url of my $filter = HTML::Filter::Callbacks->new; $filter->add_callbacks( 'img' => { start => sub { shift->replace_attr(src => sub { URI->new(shift)->canonical }) }, }, ); my $new_html = $filter->process($html); # Case 4: more complex example to enforce a submit button my $filter = HTML::Filter::Callbacks->new; $filter->add_callbacks( 'form' => { start => sub { my ($tag, $c) = @_; $c->stash->{__form_has_submit} = 0; }, end => sub { my ($tag, $c) = @_; $tag->prepend(qq/\n/) unless $c->stash->{__form_has_submit}; delete $c->stash->{__form_has_submit}; } }, 'input' => { start => sub { my ($tag, $c) = @_; $c->stash->{__form_has_submit} = 1 if $tag->attr('type') eq 'submit'; } }, ); my $new_html = $filter->process($html); # DESCRIPTION This is a rather simple HTML filter, based on [HTML::Parser](http://search.cpan.org/perldoc?HTML::Parser). It only looks for tags you add callbacks to modify something that is related to the tags (i.e. tag attributes and related comments and texts that it looked and skipped). If you want finer control, you can add extra handlers to the filter. See the SYNOPSIS and tests for usage. # METHODS ## new creates an object. ## process takes an (X)HTML, applies all the callbacks, and returns the result. ## add\_callbacks takes an array of callbacks, which typically have a tag name, and a hash reference which holds a callback for the open tag of the name (`start =` {...}>), and a callback for the close tag of the name (`end =` {...}>). The callbacks will take a HTML::Filter::Callbacks::Tag object, and the filter object itself as a context holder (stash). ## stash is just a hash reference which you can use freely in the callbacks. ## init used internally to register default callbacks. # SEE ALSO [HTML::Parser](http://search.cpan.org/perldoc?HTML::Parser) # AUTHOR Kenichi Ishigaki, Yuji Shimada # COPYRIGHT AND LICENSE Copyright (C) 2009 by Kenichi Ishigaki. This program is free software; you can redistribute it and/or modify it under the same terms as Perl itself.