MooseX::OneArgNew(3) teach ->new to accept single, non-hashref arguments


version 0.003


In our class definition:

package Delivery;
use Moose;
with('MooseX::OneArgNew' => {
type => 'Existing::Message::Type',
init_arg => 'message',
has message => (isa => 'Existing::Message::Type', required => 1);
has to => (
is => 'ro',
isa => 'Str',
lazy => 1,
default => sub {
my ($self) = @_;

When making a message:

  # The traditional way:
  my $delivery = Delivery->new({ message => $message });
  # or
  my $delivery = Delivery->new({ message => $message, to => $to });
  # With one-arg new:
  my $delivery = Delivery->new($message);


MooseX::OneArgNew lets your constructor take a single argument, which will be translated into the value for a one-entry hashref. It is a parameterized role with two parameters:
The Moose type that the single argument must be for the one-arg form to work. This should be an existing type, and may be either a string type or a MooseX::Type.
This is the string that will be used as the key for the hashref constructed from the one-arg call to new.
If true, a single argument to new will be coerced into the expected type if possible. Keep in mind that if there are no coercions for the type, this will be an error, and that if a coercion from HashRef exists, you might be getting yourself into a weird situation.


You can apply MooseX::OneArgNew more than once, but if more than one application's type matches a single argument to "new", the behavior is undefined and likely to cause bugs.

It would be a very bad idea to supply a type that could accept a normal hashref of arguments to "new".


Ricardo Signes <[email protected]>


This software is copyright (c) 2013 by Ricardo Signes.

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