release of 0.30002.

[dbsrgits/DBIx-Class.git] / lib / DBIx / Class / Schema.pm

diff --git a/lib/DBIx/Class/Schema.pm b/lib/DBIx/Class/Schema.pm
index 72928fc..116ac2e 100644 (file)
--- a/lib/DBIx/Class/Schema.pm
+++ b/lib/DBIx/Class/Schema.pm
@@ -4,8 +4,9 @@ use strict;
 use warnings;
 
 use base qw/Class::Data::Inheritable/;
-use DBIx::Class;
+use base qw/DBIx::Class/;
 
+__PACKAGE__->load_components(qw/Exception Componentised/);
 __PACKAGE__->mk_classdata('class_registrations' => {});
 
 =head1 NAME
@@ -39,14 +40,25 @@ DBIx::Class::Schema - composable schemas
 
   then in app code
 
-  my @obj = My::DB::Foo->retrieve_all; # My::DB::Foo isa My::Schema::Foo My::DB
+  my @obj = My::DB::Foo->search({}); # My::DB::Foo isa My::Schema::Foo My::DB
 
 =head1 DESCRIPTION
 
+Creates database classes based on a schema. This allows you to have more than
+one concurrent connection using the same database classes, by making 
+subclasses under a new namespace for each connection. If you only need one 
+class, you should probably use L<DBIx::Class::DB> directly instead.
+
 =head1 METHODS
 
 =over 4
 
+=item register_class <component> <component_class>
+
+Registers the class in the schema's class_registrations. This is a hash
+containing database classes, keyed by their monikers. It's used by
+compose_connection to create/modify all the existing database classes.
+
 =cut
 
 sub register_class {
@@ -56,31 +68,93 @@ sub register_class {
   $class->class_registrations(\%reg);
 }
 
+=item registered_classes
+
+Simple read-only accessor for the schema's registered classes. See 
+register_class above if you want to modify it.
+
+
+=cut
+
 sub registered_classes {
   return values %{shift->class_registrations};
 }
 
+=item  load_classes [<classes>}
+
+Uses L<Module::Find> to find all classes under the database class' namespace,
+or uses the classes you select.  Then it loads the component (using L<use>), 
+and registers them (using B<register_class>);
+
+=cut
+
 sub load_classes {
   my $class = shift;
   my @comp = grep { $_ !~ /^#/ } @_;
+  unless (@comp) {
+    eval "require Module::Find;";
+    $class->throw("No arguments to load_classes and couldn't load".
+      " Module::Find ($@)") if $@;
+    @comp = map { substr $_, length "${class}::"  }
+              Module::Find::findallmod($class);
+  }
   foreach my $comp (@comp) {
     my $comp_class = "${class}::${comp}";
-    eval "use $comp_class";
-    die $@ if $@;
+    eval "use $comp_class"; # If it fails, assume the user fixed it
     $class->register_class($comp => $comp_class);
   }
 }
 
+=item compose_connection <target> <@db_info>
+
+This is the most important method in this class. it takes a target namespace,
+as well as dbh connection info, and creates a L<DBIx::Class::DB> class as
+well as subclasses for each of your database classes in this namespace, using
+this connection.
+
+It will also setup a ->table method on the target class, which lets you
+resolve database classes based on the schema component name, for example
+
+  MyApp::DB->table('Foo') # returns MyApp::DB::Foo, 
+                          # which ISA MyApp::Schema::Foo
+
+This is the recommended API for accessing Schema generated classes, and 
+using it might give you instant advantages with future versions of DBIC.
+
+=cut
+
 sub compose_connection {
   my ($class, $target, @info) = @_;
-  $class->setup_connection_class($target, @info);
+  my $conn_class = "${target}::_db";
+  $class->setup_connection_class($conn_class, @info);
   my %reg = %{ $class->class_registrations };
+  my %target;
+  my %map;
   while (my ($comp, $comp_class) = each %reg) {
     my $target_class = "${target}::${comp}";
-    $class->inject_base($target_class, $comp_class, $target);
+    $class->inject_base($target_class, $conn_class, $comp_class);
+    $target_class->table($comp_class->table);
+    @map{$comp, $comp_class} = ($target_class, $target_class);
   }
+  {
+    no strict 'refs';
+    *{"${target}::class"} =
+      sub {
+        my ($class, $to_map) = @_;
+        return $map{$to_map};
+      };
+    *{"${target}::classes"} = sub { return \%map; };
+  }
+  $conn_class->class_resolver($target);
 }
 
+=item setup_connection_class <$target> <@info>
+
+Sets up a database connection class to inject between the schema
+and the subclasses the schema creates.
+
+=cut
+
 sub setup_connection_class {
   my ($class, $target, @info) = @_;
   $class->inject_base($target => 'DBIx::Class');
@@ -88,21 +162,13 @@ sub setup_connection_class {
   $target->connection(@info);
 }
 
-sub inject_base {
-  my ($class, $target, @to_inject) = @_;
-  {
-    no strict 'refs';
-    unshift(@{"${target}::ISA"}, @to_inject);
-  }
-}
-
 1;
 
 =back
 
 =head1 AUTHORS
 
-Matt S. Trout <perl-stuff@trout.me.uk>
+Matt S. Trout <mst@shadowcatsystems.co.uk>
 
 =head1 LICENSE