Re: Moose Accessor Question

You're looking for MooseX::AttributeHelpers:

package Wibble;
use Moose;
use MooseX::AttributeHelpers;

has 'thingies' => (
  metaclass => 'Collection::Array',
  is        => 'ro',
  isa       => 'ArrayRef[Str]',
  default   => sub { [] },
  provides  => {
      push     => 'add_thingies',
      elements => 'list_thingies',
  },
);
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This adds wrapper methods into your class to manipulate the underlying arrayref. I've given them sensible names too: add_thingies to push new elements to the end of the array, and list_thingies to return the list of values.

Now you can add additional items like so:

my $w = Wibble->new( thingies => [ 'this', 'that' ]);

print join(", ",$w->list_thingies())."\n";
# prints "this, that"

# here's the bit that we just made work
$w->add_thingies('another');

print join(", ",$w->list_thingies())."\n";
# prints "this, that, another"
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The specific methods you can provide for ArrayRef attributes are listed in MooseX::AttributeHelpers::MethodProvider::List and MooseX::AttributeHelpers::MethodProvider::Array.

I can also recommend the Moose::Manual. It's a nice overview of how Moose works, and describes some of the commonly used extensions.

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Re^2: Moose Accessor Question by pileofrogs (Priest) on Feb 06, 2009 at 23:38 UTC
++ That's what I'm looking for! Thanks! I've been reading the manual, but I hadn't found that answer. Thanks again!	[reply]
Re^2: Moose Accessor Question by Anonymous Monk on Feb 07, 2009 at 04:33 UTC
Having “been there, done that” very recently... let me toss-in what it took me a very long time to figure out. (For whatever it may be worth...) (1) The methods (like "add_thingies") are iautomagically created for you/i by Moose, and they are attached to the iobject/i. In effect, they serve to iconceal/i from any of the object's clients that the underlying data structure exists. (2) Sometimes it's overkill. Sometimes List::Util and so-forth just works best. Also, I've had my buttsky saved dozens of times now by Data::Util's `instance()` function... The very-nicest thing about Moose is, “it's still Perl.”	[reply]

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