Helper filters

• Several "standard" filters are shipped with HTTP::Proxy.

• One of them is the HTTP::Proxy::BodyFilter::tags filter, which makes sure that subsequent filters will not receive an incomplete HTML tag

• And now our simple filter just works:

        $proxy->push_filter(
            host     => 'example.com',
            response => HTTP::Proxy::BodyFilter::tags->new(),
            response => HTTP::Proxy::BodyFilter::simple->new(
                sub { ${$_[1]} =~ s!<(/?)em\b!<$1i!g; }
            )
        );

• When the HTTP::Proxy::BodyFilter::tags filter finds a < bracket without the matching >, it prevents the last piece of data to be sent to the next filter in the chain

• The missing bit is prepended to the next chunk of data going through the filters