NAME

MooX::Attribute::ENV - Allow Moo attributes to get their values from %ENV

SYNOPSIS

  package MyMod;
  use Moo;
  use MooX::Attribute::ENV;
  # look for $ENV{attr_val} and $ENV{ATTR_VAL}
  has attr => (
    is => 'ro',
    env_key => 'attr_val',
  );
  # look for $ENV{attr_val} and $ENV{next_val}, in that order
  has some => (
    is => 'ro',
    env_key => [ 'attr_val', 'next_val' ],
  );
  # looks for $ENV{otherattr} and $ENV{OTHERATTR}, then any default
  has otherattr => (
    is => 'ro',
    env => 1,
    default => 7,
  );
  # looks for $ENV{xxx_prefixattr} and $ENV{XXX_PREFIXATTR}
  has prefixattr => (
    is => 'ro',
    env_prefix => 'xxx',
  );
  # looks for $ENV{MyMod_packageattr} and $ENV{MYMOD_PACKAGEATTR}
  has packageattr => (
    is => 'ro',
    env_package_prefix => 1,
  );

  $ perl -MMyMod -E 'say MyMod->new(attr => 2)->attr'
  # 2
  $ ATTR_VAL=3 perl -MMyMod -E 'say MyMod->new->attr'
  # 3
  $ OTHERATTR=4 perl -MMyMod -E 'say MyMod->new->otherattr'
  # 4

DESCRIPTION

This is a Moo extension. It allows other attributes for "has" in Moo. If any of these are given, then "BUILDARGS" in Moo is wrapped so that values for object attributes can, if not supplied in the normal construction process, come from the environment.

The environment will be searched for either the given case, or upper case, version of the names discussed below.

When a prefix is mentioned, it will be prepended to the mentioned name, with a "_" in between.

ADDITIONAL ATTRIBUTES

env

Boolean. If true, the name is the attribute, no prefix.

env_key

String. If true, the name is the given value, no prefix.

ArrayRef. A list of names that will be checked in given order.

env_prefix

String. The prefix is the given value.

env_package_prefix

Boolean. If true, use as the prefix the current package-name, with "::" replaced with "_".

AUTHOR

Ed J, porting John Napiorkowski's excellent MooseX::Attribute::ENV.

LICENCE

The same terms as Perl itself.