NAME¶
MooseX::Getopt - A Moose role for processing command line options
VERSION¶
version 0.64
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.
METHODS¶
"new_with_options (%params)"¶
This method will take a set of default %params and then collect parameters 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
parameters 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" parameter 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".
This accessor contains an arrayref of leftover @ARGV elements that Getopt::Long
did not parse. Note that the real @ARGV is left untouched.
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"), you can either enable the
"pass_through" option of Getopt::Long for your class: "use
Getopt::Long qw(:config pass_through);" or specify a value for
MooseX::Getopt::GLD's "getopt_conf" parameter.
"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).
"print_usage_text"¶
This method is called internally when the "help_flag" state is true.
It prints the text from the "usage" object (see above) to
"stdout" and then the program terminates normally. You can apply a
method modification (see Moose::Manual::MethodModifiers) if different
behaviour is desired, for example to include additional text.
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".
This module attempts to DWIM as much as possible with the command line
parameters 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 command-line
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 command-line options.
By default, attributes which start with an underscore are not given command-line
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 parameter, 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:
command-line 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@").
More Customization Options¶
See "Configuring Getopt::Long" in 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.
SEE ALSO¶
MooseX::Getopt::Usage, an extension to generate man pages, with colour
AUTHOR¶
Stevan Little <stevan@iinteractive.com>
COPYRIGHT AND LICENSE¶
This software is copyright (c) 2007 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.
CONTRIBUTORS¶
- •
- Brandon L Black <blblack@gmail.com>
- •
- Chris Prather <chris@prather.org>
- •
- Dagfinn Ilmari Mannsaaker <ilmari@ilmari.org>
- •
- Damien Krotkine <dkrotkine@weborama.com>
- •
- Devin Austin <devin@devin-laptop.(none)>
- •
- Drew Taylor <drew@drewtaylor.com>
- •
- Florian Ragwitz <rafl@debian.org>
- •
- Gordon Irving <goraxe@goraxe.me.uk>
- •
- Hans Dieter Pearcey <hdp@weftsoar.net>
- •
- Hinrik Oern Sigurd`sson <hinrik.sig@gmail.com>
- •
- Jesse Luehrs <doy@tozt.net>
- •
- John Goulah <jgoulah@cpan.org>
- •
- Jonathan Swartz <swartz@pobox.com>
- •
- Justin Hunter <justin.d.hunter@gmail.com>
- •
- Karen Etheridge <ether@cpan.org>
- •
- Nelo Onyiah <nelo.onyiah@gmail.com>
- •
- Olaf Alders <olaf@wundersolutions.com>
- •
- Ricardo SIGNES <rjbs@cpan.org>
- •
- Ryan D Johnson <ryan@innerfence.com>
- •
- Shlomi Fish <shlomif@iglu.org.il>
- •
- Stevan Little <stevan.little@iinteractive.com>
- •
- Todd Hepler <thepler@employees.org>
- •
- Tomas Doran <bobtfish@bobtfish.net>
- •
- Yuval Kogman <nothingmuch@woobling.org>
- •
- AEvar Arnfjoerd` Bjarmason <avarab@gmail.com>
