Class::Trigger is a mixin class to invoke triggers (or hooks) in
arbitrary point, which can be registered from outside the class.
Useful for extending your own framework like Class::DBI. (In fact,
this module first implementation is extracted out from Class::DBI
0.35)
The URL
http://bulknews.net/lib/archives/Class-Trigger-0.03.tar.gz
has entered CPAN as
file: $CPAN/authors/id/M/MI/MIYAGAWA/Class-Trigger-0.03.tar.gz
size: 3651 bytes
md5: 052ed38aaf3d6b9820fa71b46937dd57
NAME
Class::Trigger - Mixin to add / call inheritable triggers
SYNOPSIS
package Foo;
use Class::Trigger;
sub foo {
my $self = shift;
$self->call_trigger('before_foo');
$self->do_foo;
$self->call_trigger('after_foo');
}
package main;
Foo->add_trigger(before_foo => \&sub1);
Foo->add_trigger(after_foo => \&sub2);
my $foo = Foo->new;
$foo->foo; # then sub1, sub2 called
# triggers are inheritable
package Bar;
use base qw(Foo);
Bar->add_trigger(before_foo => \&sub);
# triggers can be object based
$foo->add_hook(after_foo => \&sub3);
$foo->foo; # sub3 would appply only to this object
DESCRIPTION
Class::Trigger is a mixin class to add / call triggers (or hooks) that
get called at some points you specify.
METHODS
By using this module, your class is capable of following two methods.
add_trigger
Foo->add_trigger($triggerpoint => $sub);
$foo->add_trigger($triggerpoint => $sub);
Adds triggers for trigger point. You can have any number of triggers
for each point. Each coderef will be passed a copy of the object,
and return values will be ignored.
If "add_trigger" is called as object method, whole trigger table
will be copied onto the object. Then the object should be
implemented as hash.
my $foo = Foo->new;
# this trigger ($sub_foo) would apply only to $foo object
$foo->add_trigger($triggerpoint => $sub_foo);
$foo->foo;
# And not to another $bar object
my $bar = Foo->new;
$bar->foo;
call_trigger
$foo->call_trigger($triggerpoint);
Calls triggers for trigger point, which were added via "add_trigger"
method. Each triggers will be passed a copy of the object.
TRIGGER POINTS
By default you can make any number of trigger points, but if you want to
declare names of trigger points explicitly, you can do it via "import".
package Foo;
use Class::Trigger qw(foo bar baz);
package main;
Foo->add_trigger(foo => \&sub1); # okay
Foo->add_trigger(hoge => \&sub2); # exception
AUTHOR
Original idea by Tony Bowden <[EMAIL PROTECTED]> in Class::DBI.
Code by Tatsuhiko Miyagawa <[EMAIL PROTECTED]>.
This library is free software; you can redistribute it and/or modify it
under the same terms as Perl itself.
SEE ALSO
the Class::Data::Inheritable manpage
--
Tatsuhiko Miyagawa <[EMAIL PROTECTED]>
