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',
18 do { try { require MooseX::Getopt; (traits => ['Getopt']) } },
22 my ($class, %opts) = @_;
26 if(defined $opts{configfile}) {
27 $configfile = $opts{configfile}
30 # This would only succeed if the consumer had defined a new configfile
31 # sub to override the generated reader
32 $configfile = try { $class->configfile };
34 # this is gross, but since a lot of users have swapped in their own
35 # default subs, we have to keep calling it rather than calling a
36 # builder sub directly - and it might not even be a coderef either
37 my $cfmeta = $class->meta->find_attribute_by_name('configfile');
38 $configfile ||= $cfmeta->default if $cfmeta->has_default;
40 if (ref $configfile eq 'CODE') {
41 $configfile = $configfile->($class);
45 if (defined $configfile) {
46 my $hash = $class->get_config_from_file($configfile);
48 no warnings 'uninitialized';
49 croak "get_config_from_file($configfile) did not return a hash (got $hash)"
50 unless ref $hash eq 'HASH';
52 %opts = (%$hash, %opts);
66 MooseX::ConfigFromFile - An abstract Moose role for setting attributes from a configfile
71 ## A real role based on this abstract role:
74 package MooseX::SomeSpecificConfigRole;
77 with 'MooseX::ConfigFromFile';
79 use Some::ConfigFile::Loader ();
81 sub get_config_from_file {
82 my ($class, $file) = @_;
84 my $options_hashref = Some::ConfigFile::Loader->load($file);
86 return $options_hashref;
91 ## A class that uses it:
95 with 'MooseX::SomeSpecificConfigRole';
97 # optionally, default the configfile:
98 around configfile => sub { '/tmp/foo.yaml' };
100 # ... insert your stuff here ...
103 ## A script that uses the class with a configfile
106 my $obj = Foo->new_with_config(configfile => '/etc/foo.yaml', other_opt => 'foo');
110 This is an abstract role which provides an alternate constructor for creating
111 objects using parameters passed in from a configuration file. The
112 actual implementation of reading the configuration file is left to
115 It declares an attribute C<configfile> and a class method C<new_with_config>,
116 and requires that concrete roles derived from it implement the class method
117 C<get_config_from_file>.
119 Attributes specified directly as arguments to C<new_with_config> supercede those
122 L<MooseX::Getopt> knows about this abstract role, and will use it if available
123 to load attributes from the file specified by the commandline flag C<--configfile>
124 during its normal C<new_with_options>.
130 This is a L<Path::Class::File> object which can be coerced from a regular pathname
131 string. This is the file your attributes are loaded from. You can add a default
132 configfile in the consuming class and it will be honored at the appropriate time
133 (note that a simple sub declaration is not sufficient, as there is already a
134 sub by that name being added by Moose as the attribute reader)
136 around configfile => sub { '/etc/myapp.yaml' };
138 Note that you can alternately just provide a C<configfile> method which returns
139 the config file when called - this will be used in preference to the default of
142 If you have L<MooseX::Getopt> installed, this attribute will also have the
143 C<Getopt> trait supplied, so you can also set the configfile from the
148 =head2 new_with_config
150 This is an alternate constructor, which knows to look for the C<configfile> option
151 in its arguments and use that to set attributes. It is much like L<MooseX::Getopts>'s
152 C<new_with_options>. Example:
154 my $foo = SomeClass->new_with_config(configfile => '/etc/foo.yaml');
156 Explicit arguments will overide anything set by the configfile.
158 =head2 get_config_from_file
160 This class method is not implemented in this role, but it is required of all subroles.
161 Its two arguments are the classname and the configfile, and it is expected to return
162 a hashref of arguments to pass to C<new()> which are sourced from the configfile.
166 Copyright (c) - the MooseX::ConfigFromFile "AUTHOR" and "CONTRIBUTORS" as listed below.
170 Brandon L. Black, E<lt>blblack@gmail.comE<gt>
178 =item Karen Etheridge
182 =item Zbigniew Lukasiak
188 This library is free software; you can redistribute it and/or modify
189 it under the same terms as Perl itself.