Re: method as trigger

Christoph,

I don't see any reason why trigger couldn't also take a method name  
as well as a CODE ref.

However, in your example below, you pass $_[2] into &change, where $_ 
[2] is the attribute metaobject for  
'pub_in_a_TkObjectsModel_Instance'. This would not be the common  
behavior most people would expect I think.

I would be more inclined to do something like:

   trigger => 'changed'

then trigger would be expanded into this by Moose:

   trigger => sub { (shift)->changed(@_) }

which may or may not always do what you want.

I think Matt Trout may have already implemented a similar feature in  
Reaction.

- Stevan





On Jun 4, 2007, at 5:25 PM, Ch Lamprecht wrote:

> Hello,
>
> I was trying to use a method of my class as 'trigger' in an  
> attributes definition. Here is what I wrote:
>
> has pub_in_a_TkObjectsModel_Instance => ( isa => 'TkObjectsModel',
>                                           is  => 'rw',
>                                       trigger => sub{$_[0] ->  
> changed($_[2])},
>                                      );
>
> That works fine. However, are there more elegant solutions?  
> Wouldn't it be a nice feature, if we could say:
>
> ...
> trigger => 'changed',
> ...
>
> (Like in a Perl-Tk callback definition)?
>
> Christoph