new _get_default_configfile method, as the preferred way to set a default

[gitmo/MooseX-ConfigFromFile.git] / lib / MooseX / ConfigFromFile.pm

diff --git a/lib/MooseX/ConfigFromFile.pm b/lib/MooseX/ConfigFromFile.pm
index 481839e..6214934 100644 (file)
--- a/lib/MooseX/ConfigFromFile.pm
+++ b/lib/MooseX/ConfigFromFile.pm
@@ -2,18 +2,28 @@ package MooseX::ConfigFromFile;
 
 use Moose::Role;
 use MooseX::Types::Path::Tiny 'Path';
-use Try::Tiny qw/ try /;
+use MooseX::Types::Moose 'Undef';
+use Try::Tiny;
 use Carp qw(croak);
 use namespace::autoclean;
 
 requires 'get_config_from_file';
 
+# overridable in consuming class or role to provide a default value
+# This is called before instantiation, so it must be a class method,
+# and not depend on any other attributes
+sub _get_default_configfile { }
+
 has configfile => (
     is => 'ro',
-    isa => Path,
+    isa => Path|Undef,
     coerce => 1,
     predicate => 'has_configfile',
     do { try { require MooseX::Getopt; (traits => ['Getopt']) } },
+    lazy => 1,
+    # it sucks that we have to do this rather than using a builder, but some old code
+    # simply swaps in a new default sub into the attr definition
+    default => sub { shift->_get_default_configfile },
 );
 
 sub new_with_config {
@@ -26,7 +36,8 @@ sub new_with_config {
     }
     else {
         # This would only succeed if the consumer had defined a new configfile
-        # sub to override the generated reader
+        # sub to override the generated reader - as suggested in old
+        # documentation
         $configfile = try { $class->configfile };
 
         # this is gross, but since a lot of users have swapped in their own
@@ -96,7 +107,7 @@ MooseX::ConfigFromFile - An abstract Moose role for setting attributes from a co
   with 'MooseX::SomeSpecificConfigRole';
 
   # optionally, default the configfile:
-  around configfile => sub { '/tmp/foo.yaml' };
+  sub _get_default_configfile { '/tmp/foo.yaml' }
 
   # ... insert your stuff here ...
 
@@ -131,15 +142,8 @@ during its normal C<new_with_options>.
 This is a L<Path::Tiny> object which can be coerced from a regular path
 string or any object that supports stringification.
 This is the file your attributes are loaded from.  You can add a default
-configfile in the consuming class and it will be honored at the appropriate time
-(note that a simple sub declaration is not sufficient, as there is already a
-sub by that name being added by Moose as the attribute reader)
-
-  around configfile => sub { '/etc/myapp.yaml' };
-
-Note that you can alternately just provide a C<configfile> method which returns
-the config file when called - this will be used in preference to the default of
-the attribute.
+configfile in the consuming class and it will be honored at the appropriate
+time; see below at L</_get_default_configfile>.
 
 If you have L<MooseX::Getopt> installed, this attribute will also have the
 C<Getopt> trait supplied, so you can also set the configfile from the
@@ -164,6 +168,12 @@ classes or roles that consume this role.
 Its two arguments are the class name and the configfile, and it is expected to return
 a hashref of arguments to pass to C<new()> which are sourced from the configfile.
 
+=head2 _get_default_configfile
+
+This class method returns nothing by default, but can and should be redefined
+in a consuming class to return the default value of the configfile (if not
+passed into the constructor explicitly).
+
 =head1 COPYRIGHT
 
 Copyright (c) - the MooseX::ConfigFromFile "AUTHOR" and "CONTRIBUTORS" as listed below.