Toby Inkster

NAME

MooseX::WhatTheTrig - what attribute triggered me?

SYNOPSIS

   use v5.14;
   
   package Goose {
      use Moose;
      use MooseX::WhatTheTrig;
      
      has foo => (
         traits  => [ WhatTheTrig ],
         is      => 'rw',
         trigger => sub {
            my $self = shift;
            my $attr = Moose::Util::find_meta($self)->triggered_attribute;
            say "Triggered $attr";
         },
      );
   }
   
   my $obj = Goose->new(foo => 42);    # says "Triggered foo"
   $obj->foo(999);                     # says "Triggered foo"

DESCRIPTION

Moose trigger subs get passed two (sometimes three) parameters:

  • The object itself.

  • The new attribute value.

  • The old attribute value (if any).

The sub doesn't get told which attribute triggered it. This may present a problem if you wish to have the same coderef triggered from several different attributes.

This module adds a $meta->triggered_attribute method to your class' metaobject, which allows you to check which attribute has been triggered.

Yes, it works if you trigger one attribute from another attribute.

Yes, it works in roles.

Yes, it works with inheritance.

BUGS

Please report any bugs to http://rt.cpan.org/Dist/Display.html?Queue=MooseX-WhatTheTrig.

SEE ALSO

http://stackoverflow.com/questions/22306330/moose-trigger-caller.

AUTHOR

Toby Inkster <tobyink@cpan.org>.

COPYRIGHT AND LICENCE

This software is copyright (c) 2014 by Toby Inkster.

This is free software; you can redistribute it and/or modify it under the same terms as the Perl 5 programming language system itself.

DISCLAIMER OF WARRANTIES

THIS PACKAGE IS PROVIDED "AS IS" AND WITHOUT ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR A PARTICULAR PURPOSE.