subclassing MakeMethods

[water]

Hi --

I want to subclass Class::MakeMethods (to, say, MyMakeMethods) such that optional and required fields can be specified.

My goal: to have a MyMakeMethods such that I can then create a new class Foo (subclassing MyMakeMethods) with (say) scalar parameters x,y,z, where x and y must be defined on creation (and, say, z is optional). If x and y not defined, then the call to new dies.

I am having a hard time seeing how to wrap C:MakeMethods this way and would welcome suggestions.

Thanks

water

[simonm]

Hello, and thanks for your interest in Class::MakeMethods.

Subclassing Class::MakeMethods to add new types of methods is described in the "Extending" section of the documentation.

package MyMakeMethods;

use Class::MakeMethods '-isasubclass';

sub new {
  map { 
    my $name = $_->{name};
    my @required = split ' ', $_->{required};
    $name => sub {
      my ( $class, %params ) = @_;
      die unless exists $params{$_} foreach ( @required );
      bless \%params, $class;
    }
  } (shift)->_get_declarations( @_ );
}

sub get_set { 'Standard::Hash:scalar' }

1;

However, you don't need to subclass again to use those new method types; just use Class::MakeMethods's regular calling interface:

package MyFoo;

use MyMakeMethods (
  new     => { name => 'new', required => 'x y' },
  get_set => 'x y z',
);

1;

That's untested, but it should get you started. Usage might look like the following:

package main;

use MyFoo;

my $foo = MyFoo->new( x => 'Xerces', y => 'Yes' );

[water]

<dumbquestion> Thanks!! Was this (the untested required param in 'new') mentioned in the docs anywhere? I could not / still can't find it. </dumbquestion>

UPDATED -- I didn't understand simonm's code, so my question above about being in the docs makes no sense. Now I see what simonm's suggesting: this isn't in the docs, he did create MyMakeMethods. Got it. water