Re: Checking if a Moose object has a value

On 2014-02-06 Ben Edwards <[email protected]> wrote:
> for my $attr ($object->meta->get_all_attributes) {
>      my $name = $attr->name;
> 
>      # Lazy attributes that have not already been generated will not
>      # exist in the object hash.
>      next unless exists $object->{$name}

I think this is what you're after::

       next unless $attr->has_value($object);

See Class::MOP::Attribute, parent class of Moose::Meta::Attribute.

> 
>      my $value = $object->$name;

Another way to do this is::

       my $value = $attr->get_value($object);

which will bypass method modifiers applied to the read-accessor;
alternatively::

       my $reader = $attr->get_read_method;
       next unless $reader; # attribute does not have a reader
       my $value = $object->$reader();

this will call the correct read-accessor (even if it has a different
name from the attribute itself), and all applied modifiers.

>      print $value;
> }

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