1 package DBIx::Class::Schema;
7 use base qw/DBIx::Class/;
9 __PACKAGE__->load_components(qw/Exception/);
10 __PACKAGE__->mk_classdata('class_registrations' => {});
14 DBIx::Class::Schema - composable schemas
22 use base qw/DBIx::Class::Schema/;
24 __PACKAGE__->load_classes(qw/Foo Bar Baz/);
28 package My::Schema::Foo;
30 use base qw/DBIx::Class/;
32 __PACKAGE__->load_components(qw/Core PK::Auto::Pg/); # for example
33 __PACKAGE__->table('foo');
40 My::Schema->compose_connection('My::DB', $dsn, $user, $pass, $attrs);
44 my @obj = My::DB::Foo->search({}); # My::DB::Foo isa My::Schema::Foo My::DB
48 Creates database classes based on a schema. This allows you to have more than
49 one concurrent connection using the same database classes, by making
50 subclasses under a new namespace for each connection. If you only need one
51 class, you should probably use L<DBIx::Class::DB> directly instead.
53 NB: If you're used to L<Class::DBI> it's worth reading the L</SYNOPSIS>
54 carefully as DBIx::Class does things a little differently. Note in
55 particular which module inherits off which.
59 =head2 register_class <component> <component_class>
61 Registers the class in the schema's class_registrations. This is a hash
62 containing database classes, keyed by their monikers. It's used by
63 compose_connection to create/modify all the existing database classes.
68 my ($class, $name, $to_register) = @_;
69 my %reg = %{$class->class_registrations};
70 $reg{$name} = $to_register;
71 $class->class_registrations(\%reg);
74 =head2 registered_classes
76 Simple read-only accessor for the schema's registered classes. See
77 register_class above if you want to modify it.
82 sub registered_classes {
83 return values %{shift->class_registrations};
86 =head2 load_classes [<classes>, (<class>, <class>), {<namespace> => [<classes>]}]
88 Uses L<Module::Find> to find all classes under the database class' namespace,
89 or uses the classes you select. Then it loads the component (using L<use>),
90 and registers them (using B<register_class>);
92 It is possible to comment out classes with a leading '#', but note that perl
93 will think it's a mistake (trying to use a comment in a qw list) so you'll
94 need to add "no warnings 'qw';" before your load_classes call.
99 my ($class, @params) = @_;
104 foreach my $param (@params) {
105 if (ref $param eq 'ARRAY') {
106 # filter out commented entries
107 my @modules = grep { $_ !~ /^#/ } @$param;
109 push (@{$comps_for{$class}}, @modules);
111 elsif (ref $param eq 'HASH') {
112 # more than one namespace possible
113 for my $comp ( keys %$param ) {
114 # filter out commented entries
115 my @modules = grep { $_ !~ /^#/ } @{$param->{$comp}};
117 push (@{$comps_for{$comp}}, @modules);
121 # filter out commented entries
122 push (@{$comps_for{$class}}, $param) if $param !~ /^#/;
126 eval "require Module::Find;";
127 $class->throw("No arguments to load_classes and couldn't load".
128 " Module::Find ($@)") if $@;
129 my @comp = map { substr $_, length "${class}::" } Module::Find::findallmod($class);
130 $comps_for{$class} = \@comp;
133 foreach my $prefix (keys %comps_for) {
134 foreach my $comp (@{$comps_for{$prefix}||[]}) {
135 my $comp_class = "${prefix}::${comp}";
136 eval "use $comp_class"; # If it fails, assume the user fixed it
137 $class->register_class($comp => $comp_class);
142 =head2 compose_connection <target> <@db_info>
144 This is the most important method in this class. it takes a target namespace,
145 as well as dbh connection info, and creates a L<DBIx::Class::DB> class as
146 well as subclasses for each of your database classes in this namespace, using
149 It will also setup a ->table method on the target class, which lets you
150 resolve database classes based on the schema component name, for example
152 MyApp::DB->table('Foo') # returns MyApp::DB::Foo,
153 # which ISA MyApp::Schema::Foo
155 This is the recommended API for accessing Schema generated classes, and
156 using it might give you instant advantages with future versions of DBIC.
160 sub compose_connection {
161 my ($class, $target, @info) = @_;
162 my $conn_class = "${target}::_db";
163 $class->setup_connection_class($conn_class, @info);
164 my %reg = %{ $class->class_registrations };
167 while (my ($comp, $comp_class) = each %reg) {
168 my $target_class = "${target}::${comp}";
169 $class->inject_base($target_class, $comp_class, $conn_class);
170 $target_class->table($comp_class->table);
171 @map{$comp, $comp_class} = ($target_class, $target_class);
175 *{"${target}::class"} =
177 my ($class, $to_map) = @_;
178 return $map{$to_map};
180 *{"${target}::classes"} = sub { return \%map; };
182 $conn_class->class_resolver($target);
185 =head2 setup_connection_class <$target> <@info>
187 Sets up a database connection class to inject between the schema
188 and the subclasses the schema creates.
192 sub setup_connection_class {
193 my ($class, $target, @info) = @_;
194 $class->inject_base($target => 'DBIx::Class::DB');
195 #$target->load_components('DB');
196 $target->connection(@info);
203 Matt S. Trout <mst@shadowcatsystems.co.uk>
207 You may distribute this code under the same terms as Perl itself.