Re: Set attribute using 'after'

On Fri, May 11, 2012 at 08:30:13AM -0600, Curtis Jewell wrote:
> On Fri, May 11, 2012, at 15:42, Emmanuel Quevillon wrote:
> > Hi,
> > 
> > I got an exception when using 'after' this way.
> > Here is my Moose class :
> > 
> > package Myclass;
> > 
> > use Moose;
> > extends 'SuperClass';
> > with 'MyRole';
> > 
> > has 'file' => (is => 'rw', isa => 'Str', required => 1);
> > has 'fh'   => (is => 'rw', isa => 'FileHandle');
> > 
> > after 'new' => sub {
> >     my $self = shift;
> >     my $file = $self->file();
> >     $self->set_fh($self->open_file($file)); # Returns a FileHandle obj
> >     return 0;
> > };
> > 
> > 1;
> 
> You don't have a 'new' attribute to hook 'after'.
> 
> The technical name for "after 'new' => sub {" is "sub BUILD {". See
> Moose::Cookbook::Basics::Person_BUILDARGSAndBUILD for more details.

'after' modifies methods, not attributes. after 'new' is valid, although
not recommended (using BUILD is the right answer to the actual
question). The exception is caused because 'after' modifiers are called
with the original arguments, so $self there is still the string
'MyClass', not an instance that you can call attribute accessors on.

-doy