NAME

MooX::Commander::HasOptions - Moo role to add options to a subcommand

SYNOPSIS

    package PieFactory::Cmd::Throw;
    use Moo;
    with 'MooX::Commander::HasOptions';

    # This array is used to configure Getopt::Long
    sub _build_options {(
        'angrily|a',
        'speed|s=i',
    )}

    # This string is printed and the program exits.
    sub usage {
       return <<EOF
    usage: pie-factory throw <pie> <target> [options]

    Throw <pie> at <target>.  Valid values for <pie> are apple pie, rhubarb
    pie, or mud pie.

    OPTIONS
      -a, --angrily  Curse the target after throwing the pie
      -s, --speed    Throw the pie this many mph
      -h, --help     Show this message

    EOF
    }

    sub go {
        my ($self, $pie, $target) = @_;

        # print usage and then exit unsuccessfully
        $self->usage unless $pie && $target;

        # print "Not a valid value for <pie>\n", usage() and exit unsuccessfully
        $self->usage("Not a valid value for <pie>") unless $pie eq 'rhubarb';

        $self->curse_loudly if $self->options->{angrily};
        $self->throw($pie => $target, $self->options->{speed});
    }

DESCRIPTION

MooX::Commander::HasOptions is a simple Moo::Role thats adds option parsing to your module. Be sure to also read MooX::Commander.

It parses values in the $self->argv attribute with Getopt::Long. Getopt::Long is configured using the return value of _build_options().

If a user asks for help with '--help' or '-h', the usage is shown and the program exits unsuccessfully.

This module doesn't dynamically generate usage/help statements. I wasn't interested in solving that problem. I think its not possible or very difficult to do well and usually leads to a very complex and verbose user interface and a one size fits all usage/help output that is inflexible and poorly formatted.

I suspect people who really care about the usability of their command line applications will want to tweak help output based on the situation and their personal preferences.

LICENSE

Copyright (C) Eric Johnson.

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

AUTHOR

Eric Johnson <eric.git@iijo.org>