MooseX::Getopt(3)					User Contributed Perl Documentation					 MooseX::Getopt(3)

NAME

       MooseX::Getopt - A Moose role for processing command line options

SYNOPSIS

	 ## In your class
	 package My::App;
	 use Moose;

	 with 'MooseX::Getopt';

	 has 'out' => (is => 'rw', isa => 'Str', required => 1);
	 has 'in'  => (is => 'rw', isa => 'Str', required => 1);

	 # ... rest of the class here

	 ## in your script
	 #!/usr/bin/perl

	 use My::App;

	 my $app = My::App->new_with_options();
	 # ... rest of the script here

	 ## on the command line
	 % perl my_app_script.pl -in file.input -out file.dump

DESCRIPTION

       This is a role which provides an alternate constructor for creating objects using parameters passed in from the command line.

       This module attempts to DWIM as much as possible with the command line params by introspecting your class's attributes. It will use the
       name of your attribute as the command line option, and if there is a type constraint defined, it will configure Getopt::Long to handle the
       option accordingly.

       You can use the trait MooseX::Getopt::Meta::Attribute::Trait or the attribute metaclass MooseX::Getopt::Meta::Attribute to get non-default
       commandline option names and aliases.

       You can use the trait MooseX::Getopt::Meta::Attribute::Trait::NoGetopt or the attribute metaclass MooseX::Getopt::Meta::Attribute::NoGetopt
       to have "MooseX::Getopt" ignore your attribute in the commandline options.

       By default, attributes which start with an underscore are not given commandline argument support, unless the attribute's metaclass is set
       to MooseX::Getopt::Meta::Attribute. If you don't want your accessors to have the leading underscore in their name, you can do this:

	 # for read/write attributes
	 has '_foo' => (accessor => 'foo', ...);

	 # or for read-only attributes
	 has '_bar' => (reader => 'bar', ...);

       This will mean that Getopt will not handle a --foo param, but your code can still call the "foo" method.

       If your class also uses a configfile-loading role based on MooseX::ConfigFromFile, such as MooseX::SimpleConfig, MooseX::Getopt's
       "new_with_options" will load the configfile specified by the "--configfile" option (or the default you've given for the configfile
       attribute) for you.

       Options specified in multiple places follow the following precedence order: commandline overrides configfile, which overrides explicit
       new_with_options parameters.

   Supported Type Constraints
       Bool
	   A Bool type constraint is set up as a boolean option with Getopt::Long. So that this attribute description:

	     has 'verbose' => (is => 'rw', isa => 'Bool');

	   would translate into "verbose!" as a Getopt::Long option descriptor, which would enable the following command line options:

	     % my_script.pl --verbose
	     % my_script.pl --noverbose

       Int, Float, Str
	   These type constraints are set up as properly typed options with Getopt::Long, using the "=i", "=f" and "=s" modifiers as appropriate.

       ArrayRef
	   An ArrayRef type constraint is set up as a multiple value option in Getopt::Long. So that this attribute description:

	     has 'include' => (
		 is	 => 'rw',
		 isa	 => 'ArrayRef',
		 default => sub { [] }
	     );

	   would translate into "includes=s@" as a Getopt::Long option descriptor, which would enable the following command line options:

	     % my_script.pl --include /usr/lib --include /usr/local/lib

       HashRef
	   A HashRef type constraint is set up as a hash value option in Getopt::Long. So that this attribute description:

	     has 'define' => (
		 is	 => 'rw',
		 isa	 => 'HashRef',
		 default => sub { {} }
	     );

	   would translate into "define=s%" as a Getopt::Long option descriptor, which would enable the following command line options:

	     % my_script.pl --define os=linux --define vendor=debian

   Custom Type Constraints
       It is possible to create custom type constraint to option spec mappings if you need them. The process is fairly simple (but a little
       verbose maybe). First you create a custom subtype, like so:

	 subtype 'ArrayOfInts'
	     => as 'ArrayRef'
	     => where { scalar (grep { looks_like_number($_) } @$_)  };

       Then you register the mapping, like so:

	 MooseX::Getopt::OptionTypeMap->add_option_type_to_map(
	     'ArrayOfInts' => '=i@'
	 );

       Now any attribute declarations using this type constraint will get the custom option spec. So that, this:

	 has 'nums' => (
	     is      => 'ro',
	     isa     => 'ArrayOfInts',
	     default => sub { [0] }
	 );

       Will translate to the following on the command line:

	 % my_script.pl --nums 5 --nums 88 --nums 199

       This example is fairly trivial, but more complex validations are easily possible with a little creativity. The trick is balancing the type
       constraint validations with the Getopt::Long validations.

       Better examples are certainly welcome :)

   Inferred Type Constraints
       If you define a custom subtype which is a subtype of one of the standard "Supported Type Constraints" above, and do not explicitly provide
       custom support as in "Custom Type Constraints" above, MooseX::Getopt will treat it like the parent type for Getopt purposes.

       For example, if you had the same custom "ArrayOfInts" subtype from the examples above, but did not add a new custom option type for it to
       the "OptionTypeMap", it would be treated just like a normal "ArrayRef" type for Getopt purposes (that is, "=s@").

METHODS

   new_with_options (%params)
       This method will take a set of default %params and then collect params from the command line (possibly overriding those in %params) and
       then return a newly constructed object.

       The special parameter "argv", if specified should point to an array reference with an array to use instead of @ARGV.

       If "GetOptions" in Getopt::Long fails (due to invalid arguments), "new_with_options" will throw an exception.

       If Getopt::Long::Descriptive is installed and any of the following command line params are passed, the program will exit with usage
       information (and the option's state will be stored in the help_flag attribute). You can add descriptions for each option by including a
       documentation option for each attribute to document.

	 -?
	 --?
	 -h
	 --help
	 --usage

       If you have Getopt::Long::Descriptive the "usage" param is also passed to "new" as the usage option.

   ARGV
       This accessor contains a reference to a copy of the @ARGV array as it originally existed at the time of "new_with_options".

   extra_argv
       This accessor contains an arrayref of leftover @ARGV elements that Getopt::Long did not parse.  Note that the real @ARGV is left un-
       mangled.

       Important: By default, Getopt::Long will reject unrecognized options (that is, options that do not correspond with attributes using the
       Getopt trait). To disable this, and allow options to also be saved in "extra_argv" (for example to pass along to another class's
       "new_with_options"), enable the "pass_through" option of Getopt::Long for your class:  "use Getopt::Long qw(:config pass_through);"

   usage
       This accessor contains the Getopt::Long::Descriptive::Usage object (if Getopt::Long::Descriptive is used).

   help_flag
       This accessor contains the boolean state of the --help, --usage and --?	options (true if any of these options were passed on the command
       line).

   meta
       This returns the role meta object.

   process_argv (%params)
       This does most of the work of "new_with_options", analyzing the parameters and argv, except for actually calling the constructor. It
       returns a MooseX::Getopt::ProcessedArgv object. "new_with_options" uses this method internally, so modifying this method via
       subclasses/roles will affect "new_with_options".

   More Customization Options
       See Getopt::Long#Configuring_Getopt::Long for many other customizations you can make to how options are parsed. Simply "use Getopt::Long
       qw(:config other_options...)" in your class to set these.

AUTHORS

       o   Stevan Little <stevan@iinteractive.com>

       o   Brandon L. Black <blblack@gmail.com>

       o   Yuval Kogman <nothingmuch@woobling.org>

       o   Ryan D Johnson <ryan@innerfence.com>

       o   Drew Taylor <drew@drewtaylor.com>

       o   Tomas Doran <bobtfish@bobtfish.net>

       o   Florian Ragwitz <rafl@debian.org>

       o   Dagfinn Ilmari Mannsaaker <ilmari@ilmari.org>

       o   var Arnfjoer` Bjarmason <avar@cpan.org>

       o   Chris Prather <perigrin@cpan.org>

       o   Karen Etheridge <ether@cpan.org>

       o   Jonathan Swartz <swartz@pobox.com>

COPYRIGHT AND LICENSE

       This software is copyright (c) 2012 by Infinity Interactive, Inc.

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

perl v5.16.2							    2012-08-30							 MooseX::Getopt(3)