MooseX::Getopt - A Moose role for processing command line options
version 0.74
## 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
This is a role which provides an alternate constructor for creating
objects using parameters passed in from the command line.
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 the Getopt::Long manpage fails (due to invalid arguments),
new_with_options will throw an exception.
If the Getopt::Long::Descriptive manpage 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 the Getopt::Long::Descriptive manpage the usage parameter is also passed to
new as the usage option.
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
the Getopt::Long manpage did not parse. Note that the real @ARGV is left
untouched.
Important: By default, the Getopt::Long manpage 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 the Getopt::Long manpage for your class: use Getopt::Long
qw(:config pass_through); or specify a value for the MooseX::Getopt::GLD manpage's getopt_conf parameter.
This accessor contains the the Getopt::Long::Descriptive::Usage manpage object (if
the Getopt::Long::Descriptive manpage is used).
This accessor contains the boolean state of the --help, --usage and --?
options (true if any of these options were passed on the command line).
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 after this method is called, the
program terminates normally). You can apply a method modification (see
the Moose::Manual::MethodModifiers manpage) if different behaviour is desired, for
example to include additional text.
This returns the role meta object.
This does most of the work of new_with_options, analyzing the parameters
and argv, except for actually calling the constructor. It returns a
the MooseX::Getopt::ProcessedArgv manpage 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 the Getopt::Long manpage to handle the option
accordingly.
You can use the trait the MooseX::Getopt::Meta::Attribute::Trait manpage or the
attribute metaclass the MooseX::Getopt::Meta::Attribute manpage to get non-default
command-line option names and aliases.
You can use the trait the MooseX::Getopt::Meta::Attribute::Trait::NoGetopt manpage
or the attribute metaclass the MooseX::Getopt::Meta::Attribute::NoGetopt manpage
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 the MooseX::Getopt::Meta::Attribute manpage. 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 MooseX::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
the MooseX::ConfigFromFile manpage, such as the MooseX::SimpleConfig manpage,
the MooseX::Getopt manpage'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.
- Bool
-
A Bool type constraint is set up as a boolean option with
the Getopt::Long manpage. So that this attribute description:
has 'verbose' => (is => 'rw', isa => 'Bool');
would translate into verbose! as a the Getopt::Long manpage 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
the Getopt::Long manpage, using the
=i, =f and =s modifiers as appropriate.
- ArrayRef
-
An ArrayRef type constraint is set up as a multiple value option
in the Getopt::Long manpage. So that this attribute description:
has 'include' => (
is => 'rw',
isa => 'ArrayRef',
default => sub { [] }
);
would translate into includes=s@ as a the Getopt::Long manpage 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 the Getopt::Long manpage. So that this attribute description:
has 'define' => (
is => 'rw',
isa => 'HashRef',
default => sub { {} }
);
would translate into define=s% as a the Getopt::Long manpage option descriptor,
which would enable the following command line options:
% my_script.pl --define os=linux --define vendor=debian
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 the Getopt::Long manpage validations.
Better examples are certainly welcome :)
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@).
See Configuring Getopt::Long in the Getopt::Long manpage 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.
Note in particular that the default setting for case sensitivity has changed
over time in the Getopt::Long::Descriptive manpage, so if you rely on a particular
setting, you should set it explicitly, or enforce the version of
the Getopt::Long::Descriptive manpage that you install.
Bugs may be submitted through the RT bug tracker
(or bug-MooseX-Getopt@rt.cpan.org).
There is also a mailing list available for users of this distribution, at
http://lists.perl.org/list/moose.html.
There is also an irc channel available for users of this distribution, at
#moose on irc.perl.org.
Stevan Little <stevan@iinteractive.com>
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.
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