From: Shawn M Moore <sartak@gmail.com>
Date: Wed, 26 Nov 2008 07:45:20 +0000 (+0000)
Subject: Begin working out the tutorial
X-Git-Tag: 0.05~61
X-Git-Url: http://git.shadowcat.co.uk/gitweb/gitweb.cgi?a=commitdiff_plain;h=d2abd7563c59eeffddeb9be74ce797e49d168be3;p=gitmo%2FMooseX-Role-Parameterized.git

Begin working out the tutorial
---

diff --git a/lib/MooseX/Role/Parameterized/Tutorial.pm b/lib/MooseX/Role/Parameterized/Tutorial.pm
index 5842fa9..ab67341 100644
--- a/lib/MooseX/Role/Parameterized/Tutorial.pm
+++ b/lib/MooseX/Role/Parameterized/Tutorial.pm
@@ -7,8 +7,20 @@ __END__
 
 MooseX::Role::Parameterized::Tutorial - why and how
 
+=head1 ROLES
+
+Roles are composable units of behavior. See L<Moose::Cookbook::Roles::Recipe1>
+for an introduction to L<Moose::Role>.
+
 =head1 MOTIVATION
 
+Roles are exceedingly useful. While combining roles affords you a great deal of
+flexibility, individual roles have very little in the way of configurability.
+Core Moose provides C<alias> for renaming methods to avoid conflicts, and
+C<excludes> for ignoring methods you don't want or need (see
+L<Moose::Cookbook::Roles::Recipe2> for more about C<alias> and C<excludes>).
+
+
 =head1 USAGE
 
 =head3 C<with>
@@ -19,5 +31,80 @@ MooseX::Role::Parameterized::Tutorial - why and how
 
 =head1 IMPLEMENTATION NOTES
 
+=head1 USES
+
+Ideally these will become fully-explained examples in something resembling
+L<Moose::Cookbook>. But for now, only a braindump.
+
+=over 4
+
+=item Configure a role's attributes
+
+You can rename methods with core Moose, but now you can rename attributes. You
+can now also choose type, default value, whether it's required, B<traits>, etc.
+
+    parameter traits => (
+        is      => 'ro',
+        isa     => 'ArrayRef[Str]',
+        default => sub { [] },
+    );
+
+    has action => (
+        traits => $p->traits,
+        ...
+    );
+
+=item Inform a role of your class' attributes and methods
+
+Core roles can require only methods with specific names. Now your roles can
+require that you specify a method name you wish the role to instrument, or
+which attributes to dump to a file.
+
+    parameter instrument_method => (
+        is       => 'ro',
+        isa      => 'Str',
+        required => 1,
+    );
+
+    around $p->instrument_method => sub { ... };
+
+=item Arbitrary execution choices
+
+Your role may be able to provide configuration in how the role's methods
+operate. For example, you can tell the role whether to save intermediate
+states.
+
+    parameter save_intermediate => (
+        is      => 'ro',
+        isa     => 'Bool',
+        default => 0,
+    );
+
+    method process => sub {
+        ...
+        if ($p->save_intermediate) { ... }
+        ...
+    };
+
+=item Deciding a backend
+
+Your role may be able to freeze and thaw your instances using L<YAML>, L<JSON>,
+L<Storable>. Which backend to use can be a parameter.
+
+    parameter format => (
+        is => 'ro',
+        isa => (enum ['Storable', 'YAML', 'JSON']),
+        default => 'Storable',
+    );
+
+    if ($p->format eq 'Storable') {
+        method freeze => sub { ... };
+        method thaw   => sub { ... };
+    }
+    elsif ($p->format eq 'YAML') ...
+    ...
+
+=back
+
 =cut