X-Git-Url: http://git.shadowcat.co.uk/gitweb/gitweb.cgi?a=blobdiff_plain;f=lib%2FDBIx%2FClass%2FSchema.pm;h=fa8e85073393d30a7cea8d24a135bd21aab658f6;hb=cda04c3afd46989e1964a6c8a277fd7faa11b291;hp=fd992e19939fd8343dcee69edcf9c22d28459d32;hpb=a02675cd9a11e1f354220319da9f5d573a2e484a;p=dbsrgits%2FDBIx-Class.git

diff --git a/lib/DBIx/Class/Schema.pm b/lib/DBIx/Class/Schema.pm
index fd992e1..fa8e850 100644
--- a/lib/DBIx/Class/Schema.pm
+++ b/lib/DBIx/Class/Schema.pm
@@ -2,46 +2,211 @@ package DBIx::Class::Schema;
 
 use strict;
 use warnings;
+use DBIx::Class::DB;
 
-use base qw/Class::Data::Inheritable/;
-use DBIx::Class;
+use base qw/DBIx::Class/;
 
-__PACKAGE__->mk_classdata('_class_registrations' => {});
+__PACKAGE__->load_components(qw/Exception/);
+__PACKAGE__->mk_classdata('class_registrations' => {});
+
+=head1 NAME
+
+DBIx::Class::Schema - composable schemas
+
+=head1 SYNOPSIS
+
+in My/Schema.pm
+
+  package My::Schema;
+
+  use base qw/DBIx::Class::Schema/;
+
+  __PACKAGE__->load_classes(qw/Foo Bar Baz/);
+
+in My/Schema/Foo.pm
+
+  package My::Schema::Foo;
+
+  use base qw/DBIx::Class/;
+
+  __PACKAGE__->load_components(qw/Core PK::Auto::Pg/); # for example
+  __PACKAGE__->table('foo');
+  ...
+
+in My/DB.pm
+
+  use My::Schema;
+
+  My::Schema->compose_connection('My::DB', $dsn, $user, $pass, $attrs);
+
+then in app code
+
+  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.
+
+NB: If you're used to L<Class::DBI> it's worth reading the L</SYNOPSIS>
+carefully as DBIx::Class does things a little differently. Note in
+particular which module inherits off which.
+
+=head1 METHODS
+
+=head2 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 {
   my ($class, $name, $to_register) = @_;
-  my %reg = %{$class->_class_registrations};
+  my %reg = %{$class->class_registrations};
   $reg{$name} = $to_register;
-  $class->_class_registrations(\%reg);
+  $class->class_registrations(\%reg);
+}
+
+=head2 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};
 }
 
+=head2  load_classes [<classes>, (<class>, <class>), {<namespace> => [<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>);
+
+It is possible to comment out classes with a leading '#', but note that perl
+will think it's a mistake (trying to use a comment in a qw list) so you'll
+need to add "no warnings 'qw';" before your load_classes call.
+
+=cut
+
 sub load_classes {
-  my $class = shift;
-  my @comp = grep { $_ !~ /^#/ } @_;
-  foreach my $comp (@comp) {
-    my $comp_class = "${class}::${comp}";
-    eval "use $comp_class";
-    die $@ if $@;
-    $class->register_class($comp => $comp_class);
+  my ($class, @params) = @_;
+  
+  my %comps_for;
+  
+  if (@params) {
+    foreach my $param (@params) {
+      if (ref $param eq 'ARRAY') {
+        # filter out commented entries
+        my @modules = grep { $_ !~ /^#/ } @$param;
+        
+        push (@{$comps_for{$class}}, @modules);
+      }
+      elsif (ref $param eq 'HASH') {
+        # more than one namespace possible
+        for my $comp ( keys %$param ) {
+          # filter out commented entries
+          my @modules = grep { $_ !~ /^#/ } @{$param->{$comp}};
+
+          push (@{$comps_for{$comp}}, @modules);
+        }
+      }
+      else {
+        # filter out commented entries
+        push (@{$comps_for{$class}}, $param) if $param !~ /^#/;
+      }
+    }
+  } else {
+    eval "require Module::Find;";
+    $class->throw("No arguments to load_classes and couldn't load".
+      " Module::Find ($@)") if $@;
+    my @comp = map { substr $_, length "${class}::"  } Module::Find::findallmod($class);
+    $comps_for{$class} = \@comp;
+  }
+
+  foreach my $prefix (keys %comps_for) {
+    foreach my $comp (@{$comps_for{$prefix}||[]}) {
+      my $comp_class = "${prefix}::${comp}";
+      eval "use $comp_class"; # If it fails, assume the user fixed it
+      $class->register_class($comp => $comp_class);
+    }
   }
 }
 
+=head2 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) = @_;
+  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, $conn_class);
+    my $table = $comp_class->table->new({ %{$comp_class->table} });
+    $table->result_class($target_class);
+    $target_class->table($table);
+    @map{$comp, $comp_class} = ($target_class, $target_class);
+  }
   {
     no strict 'refs';
-    unshift(@{"${target}::ISA"}, 'DBIx::Class');
+    *{"${target}::class"} =
+      sub {
+        my ($class, $to_map) = @_;
+        return $map{$to_map};
+      };
+    *{"${target}::classes"} = sub { return \%map; };
   }
-  $target->load_components('DB');
+  $conn_class->class_resolver($target);
+}
+
+=head2 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::DB');
+  #$target->load_components('DB');
   $target->connection(@info);
-  my %reg = %{ $class->_class_registrations };
-  while (my ($comp, $comp_class) = each %reg) {
-    my $target_class = "${target}::${comp}";
-    {
-      no strict 'refs';
-      unshift(@{"${target_class}::ISA"}, $comp_class, $target);
-    }
-  }
 }
 
 1;
+
+=head1 AUTHORS
+
+Matt S. Trout <mst@shadowcatsystems.co.uk>
+
+=head1 LICENSE
+
+You may distribute this code under the same terms as Perl itself.
+
+=cut
+