perl - How to call method within builder -

i have class attribute set follows:

has _data => (     => 'ro',     lazy => 1,     builder => '_load', );  sub _load {     $self = shift;     return retrieve $self->_file; } 

however want call method defined on class before returning data.

in old-school perl oo, i'd doing this:

sub _load {     # assuming laziness implemented somewhere else.     $self = shift;     $self->{_data} = retrieve $self->_file;     $self->refresh;  # $self->{_data}     return $self->{_data}; } 

but can't figure out 'clean' way in moose.

i've considered following, think quite ugly, , there must better way of doing this.

• if make _data read-write, potentially write data accessor, call method return value accessor moose write accessor.
• if turn plain old method i'd have define attribute, _raw_data, store data in there, modify refresh() use attribute, , else uses _data().
• violate encapsulation , access underlying $self->{_data} directly.

i tried after '_load' => \&refresh;, created endless loop.

this nice use of triggers:

has _data => (         => 'ro',    lazy    => 1,    builder => '_load',    trigger => sub { shift->refresh }, ); 

except triggers don't work on default/built values - on values passed constructor explicitly, or passed writer/accessor method. sad face. :-(

one solution rewrite refresh method instead of operating on $self->_data, can accept parameter (perhaps falling operating on $self->_data if no parameter given.

sub _load {    $self = shift;    $tmp = retrieve $self->_file;    $self->refresh($tmp);    return $tmp; }  sub refresh {    $self = shift;    $data = scalar(@_) ? $_[0] : $self->_data;    # $data }