Pass variables around the around method modifier

2019-02-28 23:48发布

问题:

Is it possible to pass variables between multiple calls to the around MethodModier? example (that doesn't work but hopefully conveys what I want to do)

sub mysub { ... };

around 'mysub' => sub {
   my $orig = shift;
   my $self = shift;

   my $value = get_value;

   $self->orig(@_);
};

around 'mysub' => sub {
   my $orig = shift;
   my $self = shift;
   my $value = shift;

   my $output
       = "sometext $value"
       . $self->orig(@_);
       . 'someothertext $value'
       ;
};

I'd eventually like to have these 'arounds' placed in pluggable traits, where I won't really know which ones are loaded beforehand but the final output will be neatly formatted.

It's possible that I'm thinking about this completely wrong, so other suggestions welcome.

回答1:

What you are trying to do don't have logic.

"An around modifier receives the original method as its first argument, then the object, and finally any arguments passed to the method."

https://metacpan.org/pod/Moose::Manual::MethodModifiers#BEFORE-AFTER-AND-AROUND



回答2:

Use an instance variable:

$self->{value} = get_value;
...
my $value = $self->{value};

(See question commments for an actual answer. I'm just reiterating it here, so I can accept an answer, thanks to:

)