NAME MooseX::ConfigFromFile - An abstract Moose role for setting attributes from a configfile SYNOPSIS ######## ## A real role based on this abstract role: ######## package MooseX::SomeSpecificConfigRole; use Moose::Role; with 'MooseX::ConfigFromFile'; use Some::ConfigFile::Loader (); sub get_config_from_file { my ($class, $file) = @_; my $options_hashref = Some::ConfigFile::Loader->load($file); return $options_hashref; } ######## ## A class that uses it: ######## package Foo; use Moose; with 'MooseX::SomeSpecificConfigRole'; # optionally, default the configfile: sub configfile { '/tmp/foo.yaml' } # ... insert your stuff here ... ######## ## A script that uses the class with a configfile ######## my $obj = Foo->new_with_config(configfile => '/etc/foo.yaml', other_opt => 'foo'); DESCRIPTION This is an abstract role which provides an alternate constructor for creating objects using parameters passed in from a configuration file. The actual implementation of reading the configuration file is left to concrete subroles. It declares an attribute "configfile" and a class method "new_with_config", and requires that concrete roles derived from it implement the class method "get_config_from_file". Attributes specified directly as arguments to "new_with_config" supercede those in the configfile. MooseX::Getopt knows about this abstract role, and will use it if available to load attributes from the file specified by the commandline flag "--configfile" during its normal "new_with_options". Attributes configfile This is a Path::Class::File object which can be coerced from a regular pathname string. This is the file your attributes are loaded from. You can add a default configfile in the class using the role and it will be honored at the appropriate time: has +configfile ( default => '/etc/myapp.yaml' ); Note that you can alternately just provide a "configfile" method which returns the config file when called - this will be used in preference to the default of the attribute. Class Methods new_with_config This is an alternate constructor, which knows to look for the "configfile" option in its arguments and use that to set attributes. It is much like MooseX::Getopts's "new_with_options". Example: my $foo = SomeClass->new_with_config(configfile => '/etc/foo.yaml'); Explicit arguments will overide anything set by the configfile. get_config_from_file This class method is not implemented in this role, but it is required of all subroles. Its two arguments are the classname and the configfile, and it is expected to return a hashref of arguments to pass to "new()" which are sourced from the configfile. COPYRIGHT Copyright (c) 2007 - 2009 the MooseX::ConfigFromFile "AUTHOR" and "CONTRIBUTORS" as listed below. AUTHOR Brandon L. Black, CONTRIBUTORS Tomas Doran "" (current maintainer). Karen Etheridge Chris Prather Zbigniew Lukasiak LICENSE This library is free software; you can redistribute it and/or modify it under the same terms as Perl itself.