1 package MooseX::Getopt;
2 # ABSTRACT: A Moose role for processing command line options
6 use constant _HAVE_GLD => not not eval { require Getopt::Long::Descriptive };
8 with _HAVE_GLD ? 'MooseX::Getopt::GLD' : 'MooseX::Getopt::Basic';
20 with 'MooseX::Getopt';
22 has 'out' => (is => 'rw', isa => 'Str', required => 1);
23 has 'in' => (is => 'rw', isa => 'Str', required => 1);
25 # ... rest of the class here
32 my $app = My::App->new_with_options();
33 # ... rest of the script here
35 ## on the command line
36 % perl my_app_script.pl -in file.input -out file.dump
40 This is a role which provides an alternate constructor for creating
41 objects using parameters passed in from the command line.
43 This module attempts to DWIM as much as possible with the command line
44 params by introspecting your class's attributes. It will use the name
45 of your attribute as the command line option, and if there is a type
46 constraint defined, it will configure Getopt::Long to handle the option
49 You can use the trait L<MooseX::Getopt::Meta::Attribute::Trait> or the
50 attribute metaclass L<MooseX::Getopt::Meta::Attribute> to get non-default
51 commandline option names and aliases.
53 You can use the trait L<MooseX::Getopt::Meta::Attribute::Trait::NoGetopt>
54 or the attribute metaclass L<MooseX::Getopt::Meta::Attribute::NoGetopt>
55 to have C<MooseX::Getopt> ignore your attribute in the commandline options.
57 By default, attributes which start with an underscore are not given
58 commandline argument support, unless the attribute's metaclass is set
59 to L<MooseX::Getopt::Meta::Attribute>. If you don't want your accessors
60 to have the leading underscore in their name, you can do this:
62 # for read/write attributes
63 has '_foo' => (accessor => 'foo', ...);
65 # or for read-only attributes
66 has '_bar' => (reader => 'bar', ...);
68 This will mean that Getopt will not handle a --foo param, but your
69 code can still call the C<foo> method.
71 If your class also uses a configfile-loading role based on
72 L<MooseX::ConfigFromFile>, such as L<MooseX::SimpleConfig>,
73 L<MooseX::Getopt>'s C<new_with_options> will load the configfile
74 specified by the C<--configfile> option (or the default you've
75 given for the configfile attribute) for you.
77 Options specified in multiple places follow the following
78 precendence order: commandline overrides configfile, which
79 overrides explicit new_with_options parameters.
81 =head2 Supported Type Constraints
87 A I<Bool> type constraint is set up as a boolean option with
88 Getopt::Long. So that this attribute description:
90 has 'verbose' => (is => 'rw', isa => 'Bool');
92 would translate into C<verbose!> as a Getopt::Long option descriptor,
93 which would enable the following command line options:
95 % my_script.pl --verbose
96 % my_script.pl --noverbose
98 =item I<Int>, I<Float>, I<Str>
100 These type constraints are set up as properly typed options with
101 Getopt::Long, using the C<=i>, C<=f> and C<=s> modifiers as appropriate.
105 An I<ArrayRef> type constraint is set up as a multiple value option
106 in Getopt::Long. So that this attribute description:
111 default => sub { [] }
114 would translate into C<includes=s@> as a Getopt::Long option descriptor,
115 which would enable the following command line options:
117 % my_script.pl --include /usr/lib --include /usr/local/lib
121 A I<HashRef> type constraint is set up as a hash value option
122 in Getopt::Long. So that this attribute description:
127 default => sub { {} }
130 would translate into C<define=s%> as a Getopt::Long option descriptor,
131 which would enable the following command line options:
133 % my_script.pl --define os=linux --define vendor=debian
137 =head2 Custom Type Constraints
139 It is possible to create custom type constraint to option spec
140 mappings if you need them. The process is fairly simple (but a
141 little verbose maybe). First you create a custom subtype, like
144 subtype 'ArrayOfInts'
146 => where { scalar (grep { looks_like_number($_) } @$_) };
148 Then you register the mapping, like so:
150 MooseX::Getopt::OptionTypeMap->add_option_type_to_map(
151 'ArrayOfInts' => '=i@'
154 Now any attribute declarations using this type constraint will
155 get the custom option spec. So that, this:
159 isa => 'ArrayOfInts',
160 default => sub { [0] }
163 Will translate to the following on the command line:
165 % my_script.pl --nums 5 --nums 88 --nums 199
167 This example is fairly trivial, but more complex validations are
168 easily possible with a little creativity. The trick is balancing
169 the type constraint validations with the Getopt::Long validations.
171 Better examples are certainly welcome :)
173 =head2 Inferred Type Constraints
175 If you define a custom subtype which is a subtype of one of the
176 standard L</Supported Type Constraints> above, and do not explicitly
177 provide custom support as in L</Custom Type Constraints> above,
178 MooseX::Getopt will treat it like the parent type for Getopt
181 For example, if you had the same custom C<ArrayOfInts> subtype
182 from the examples above, but did not add a new custom option
183 type for it to the C<OptionTypeMap>, it would be treated just
184 like a normal C<ArrayRef> type for Getopt purposes (that is,
187 =method B<new_with_options (%params)>
189 This method will take a set of default C<%params> and then collect
190 params from the command line (possibly overriding those in C<%params>)
191 and then return a newly constructed object.
193 The special parameter C<argv>, if specified should point to an array
194 reference with an array to use instead of C<@ARGV>.
196 If L<Getopt::Long/GetOptions> fails (due to invalid arguments),
197 C<new_with_options> will throw an exception.
199 If L<Getopt::Long::Descriptive> is installed and any of the following
200 command line params are passed, the program will exit with usage
201 information. You can add descriptions for each option by including a
202 B<documentation> option for each attribute to document.
208 If you have L<Getopt::Long::Descriptive> the C<usage> param is also passed to
213 This accessor contains a reference to a copy of the C<@ARGV> array
214 as it originally existed at the time of C<new_with_options>.
216 =method B<extra_argv>
218 This accessor contains an arrayref of leftover C<@ARGV> elements that
219 L<Getopt::Long> did not parse. Note that the real C<@ARGV> is left
224 This returns the role meta object.