Class::Method::Modifiers::Fast - provides Moose-like method modifiers
package Child;
use parent 'Parent';
use Class::Method::Modifiers::Fast;
sub new_method { }
before 'old_method' => sub {
carp "old_method is deprecated, use new_method";
};
around 'other_method' => sub {
my $orig = shift;
my $ret = $orig->(@_);
return $ret =~ /\d/ ? $ret : lc $ret;
};
Method modifiers are a powerful feature from the CLOS (Common Lisp Object
System) world.
"Class::Method::Modifiers::Fast"
provides three modifiers: "before",
"around", and
"after".
"before" and
"after" are run just before and after the
method they modify, but can not really affect that original method.
"around" is run in place of the original
method, with a hook to easily call that original method. See the
"MODIFIERS" section for more details on
how the particular modifiers work.
"before" is called before the method it is
modifying. Its return value is totally ignored. It receives the same
@_ as the the method it is modifying would have
received. You can modify the @_ the original method
will receive by changing $_[0] and friends (or by
changing anything inside a reference). This is a feature!
"after" is called after the method it is
modifying. Its return value is totally ignored. It receives the same
@_ as the the method it is modifying received, mostly.
The original method can modify @_ (such as by changing
$_[0] or references) and
"after" will see the modified version. If
you don't like this behavior, specify both a
"before" and
"after", and copy the
@_ during "before"
for "after" to use.
"around" is called instead of the method it is
modifying. The method you're overriding is passed in as the first argument
(called $orig by convention). Watch out for contextual
return values of $orig.
You can use "around" to:
- Pass $orig a different @_
-
around 'method' => sub {
my $orig = shift;
my $self = shift;
$orig->($self, reverse @_);
};
- Munge the return value of $orig
-
around 'method' => sub {
my $orig = shift;
ucfirst $orig->(@_);
};
- Avoid calling $orig -- conditionally
-
around 'method' => sub {
my $orig = shift;
return $orig->(@_) if time() % 2;
return "no dice, captain";
};
Takatoshi Kitano <kitano.tk@gmail.com> gfx
This library is free software; you can redistribute it and/or modify it under
the same terms as Perl itself.