1 package MooseX::ConfigFromFile;
4 use MooseX::Types::Path::Class qw( File );
5 use Try::Tiny qw/ try /;
7 use namespace::autoclean;
11 requires 'get_config_from_file';
17 predicate => 'has_configfile',
21 my ($class, %opts) = @_;
25 if(defined $opts{configfile}) {
26 $configfile = $opts{configfile}
29 # This would only succeed if the consumer had defined a new configfile
30 # sub to override the generated reader
31 $configfile = try { $class->configfile };
33 # this is gross, but since a lot of users have swapped in their own
34 # default subs, we have to keep calling it rather than calling a
35 # builder sub directly - and it might not even be a coderef either
36 my $cfmeta = $class->meta->find_attribute_by_name('configfile');
37 $configfile ||= $cfmeta->default if $cfmeta->has_default;
39 if (ref $configfile eq 'CODE') {
40 $configfile = $configfile->($class);
44 if (defined $configfile) {
45 my $hash = $class->get_config_from_file($configfile);
47 no warnings 'uninitialized';
48 croak "get_config_from_file($configfile) did not return a hash (got $hash)"
49 unless ref $hash eq 'HASH';
51 %opts = (%$hash, %opts);
65 MooseX::ConfigFromFile - An abstract Moose role for setting attributes from a configfile
70 ## A real role based on this abstract role:
73 package MooseX::SomeSpecificConfigRole;
76 with 'MooseX::ConfigFromFile';
78 use Some::ConfigFile::Loader ();
80 sub get_config_from_file {
81 my ($class, $file) = @_;
83 my $options_hashref = Some::ConfigFile::Loader->load($file);
85 return $options_hashref;
90 ## A class that uses it:
94 with 'MooseX::SomeSpecificConfigRole';
96 # optionally, default the configfile:
97 around configfile => sub { '/tmp/foo.yaml' };
99 # ... insert your stuff here ...
102 ## A script that uses the class with a configfile
105 my $obj = Foo->new_with_config(configfile => '/etc/foo.yaml', other_opt => 'foo');
109 This is an abstract role which provides an alternate constructor for creating
110 objects using parameters passed in from a configuration file. The
111 actual implementation of reading the configuration file is left to
114 It declares an attribute C<configfile> and a class method C<new_with_config>,
115 and requires that concrete roles derived from it implement the class method
116 C<get_config_from_file>.
118 Attributes specified directly as arguments to C<new_with_config> supercede those
121 L<MooseX::Getopt> knows about this abstract role, and will use it if available
122 to load attributes from the file specified by the commandline flag C<--configfile>
123 during its normal C<new_with_options>.
129 This is a L<Path::Class::File> object which can be coerced from a regular pathname
130 string. This is the file your attributes are loaded from. You can add a default
131 configfile in the consuming class and it will be honored at the appropriate time
132 (note that a simple sub declaration is not sufficient, as there is already a
133 sub by that name being added by Moose as the attribute reader)
135 around configfile => sub { '/etc/myapp.yaml' };
137 Note that you can alternately just provide a C<configfile> method which returns
138 the config file when called - this will be used in preference to the default of
143 =head2 new_with_config
145 This is an alternate constructor, which knows to look for the C<configfile> option
146 in its arguments and use that to set attributes. It is much like L<MooseX::Getopts>'s
147 C<new_with_options>. Example:
149 my $foo = SomeClass->new_with_config(configfile => '/etc/foo.yaml');
151 Explicit arguments will overide anything set by the configfile.
153 =head2 get_config_from_file
155 This class method is not implemented in this role, but it is required of all subroles.
156 Its two arguments are the classname and the configfile, and it is expected to return
157 a hashref of arguments to pass to C<new()> which are sourced from the configfile.
161 Copyright (c) 2007 - 2009 the MooseX::ConfigFromFile "AUTHOR" and "CONTRIBUTORS" as listed below.
165 Brandon L. Black, E<lt>blblack@gmail.comE<gt>
171 =item Tomas Doran C<< <bobtfish@bobtfish.net> >> (current maintainer).
173 =item Karen Etheridge
177 =item Zbigniew Lukasiak
183 This library is free software; you can redistribute it and/or modify
184 it under the same terms as Perl itself.