1 package MooseX::ConfigFromFile;
4 use MooseX::Types::Path::Class qw( File );
8 requires 'get_config_from_file';
14 predicate => 'has_configfile',
18 my ($class, %opts) = @_;
22 if(defined $opts{configfile}) {
23 $configfile = $opts{configfile}
26 my $cfmeta = $class->meta->get_attribute('configfile');
27 $configfile = $cfmeta->default if $cfmeta->has_default;
30 if(defined $configfile) {
31 %opts = (%{$class->get_config_from_file($configfile)}, %opts);
45 MooseX::ConfigFromFile - An abstract Moose role for setting attributes from a configfile
50 ## A real role based on this abstract role:
53 package MooseX::SomeSpecificConfigRole;
56 with 'MooseX::ConfigFromFile';
58 use Some::ConfigFile::Loader ();
60 sub get_config_from_file {
61 my ($class, $file) = @_;
63 my $options_hashref = Some::ConfigFile::Loader->load($file);
65 return $options_hashref;
70 ## A class that uses it:
74 with 'MooseX::SomeSpecificConfigRole';
76 # optionally, default the configfile:
77 has +configfile ( default => '/tmp/foo.yaml' );
79 # ... insert your stuff here ...
82 ## A script that uses the class with a configfile
85 my $obj = Foo->new_with_config(configfile => '/etc/foo.yaml', other_opt => 'foo');
89 This is an abstract role which provides an alternate constructor for creating
90 objects using parameters passed in from a configuration file. The
91 actual implementation of reading the configuration file is left to
94 It declares an attribute C<configfile> and a class method C<new_with_config>,
95 and requires that concrete roles derived from it implement the class method
96 C<get_config_from_file>.
98 Attributes specified directly as arguments to C<new_with_config> supercede those
101 L<MooseX::Getopt> knows about this abstract role, and will use it if available
102 to load attributes from the file specified by the commandline flag C<--configfile>
103 during its normal C<new_with_options>.
109 This is a L<Path::Class::File> object which can be coerced from a regular pathname
110 string. This is the file your attributes are loaded from. You can add a default
111 configfile in the class using the role and it will be honored at the appropriate time:
113 has +configfile ( default => '/etc/myapp.yaml' );
117 =head2 new_with_config
119 This is an alternate constructor, which knows to look for the C<configfile> option
120 in its arguments and use that to set attributes. It is much like L<MooseX::Getopts>'s
121 C<new_with_options>. Example:
123 my $foo = SomeClass->new_with_config(configfile => '/etc/foo.yaml');
125 Explicit arguments will overide anything set by the configfile.
127 =head2 get_config_from_file
129 This class method is not implemented in this role, but it is required of all subroles.
130 Its two arguments are the classname and the configfile, and it is expected to return
131 a hashref of arguments to pass to C<new()> which are sourced from the configfile.
135 The Moose meta stuff, included here because otherwise pod tests fail sometimes
141 Brandon L. Black, E<lt>blblack@gmail.comE<gt>
145 This library is free software; you can redistribute it and/or modify
146 it under the same terms as Perl itself.