MooseX::Getopt(3) User Contributed Perl Documentation MooseX::Getopt(3)NAMEMooseX::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 precendence
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.
--?
--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
· Stevan Little <stevan@iinteractive.com>
· Brandon L. Black <blblack@gmail.com>
· Yuval Kogman <nothingmuch@woobling.org>
· Ryan D Johnson <ryan@innerfence.com>
· Drew Taylor <drew@drewtaylor.com>
· Tomas Doran <bobtfish@bobtfish.net>
· Florian Ragwitz <rafl@debian.org>
· Dagfinn Ilmari Mannsaaker <ilmari@ilmari.org>
· var Arnfjoer` Bjarmason <avar@cpan.org>
· Chris Prather <perigrin@cpan.org>
· Karen Etheridge <ether@cpan.org>
· 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.
POD ERRORS
Hey! The above document had some coding errors, which are explained
below:
Around line 273:
=back without =over
perl v5.14.2 2012-02-03 MooseX::Getopt(3)
