sub parse {
    my ($self, $xmlfile) = @_;

    my $parser = XML::Parser->new(
        Handlers => {Start => sub { $self->handle_start(@_) },
                     End   => sub { $self->handle_end(@_) },
                     Char  => sub { $self->handle_char(@_) },
    );

    $parser->parsefile($xmlfile);
}

sub handle_start {
    my ($self, $parser, @args) = @_;
    print $self->{i_need_this};
    ...
};

...