use strict;
use warnings;
+use DBIx::Class::DB;
-use base qw/Class::Data::Inheritable/;
-use DBIx::Class;
+use base qw/DBIx::Class/;
+__PACKAGE__->load_components(qw/Exception/);
__PACKAGE__->mk_classdata('class_registrations' => {});
+__PACKAGE__->mk_classdata('storage_type' => 'DBI');
+__PACKAGE__->mk_classdata('storage');
=head1 NAME
=head1 SYNOPSIS
- in My/Schema.pm
+in My/Schema.pm
package My::Schema;
__PACKAGE__->load_classes(qw/Foo Bar Baz/);
- in My/Schema/Foo.pm
+in My/Schema/Foo.pm
package My::Schema::Foo;
- use base qw/DBIx::Class::Core/;
+ use base qw/DBIx::Class/;
+ __PACKAGE__->load_components(qw/PK::Auto::Pg Core/); # for example
__PACKAGE__->table('foo');
...
- in My/DB.pm
+in My/DB.pm
use My::Schema;
My::Schema->compose_connection('My::DB', $dsn, $user, $pass, $attrs);
- then in app code
+then in app code
my @obj = My::DB::Foo->search({}); # My::DB::Foo isa My::Schema::Foo My::DB
=head1 DESCRIPTION
+Creates database classes based on a schema. This allows you to have more than
+one concurrent connection using the same database classes, by making
+subclasses under a new namespace for each connection. If you only need one
+class, you should probably use L<DBIx::Class::DB> directly instead.
+
+NB: If you're used to L<Class::DBI> it's worth reading the L</SYNOPSIS>
+carefully as DBIx::Class does things a little differently. Note in
+particular which module inherits off which.
+
=head1 METHODS
-=over 4
+=head2 register_class <component> <component_class>
+
+Registers the class in the schema's class_registrations. This is a hash
+containing database classes, keyed by their monikers. It's used by
+compose_connection to create/modify all the existing database classes.
=cut
sub register_class {
- my ($class, $name, $to_register) = @_;
- my %reg = %{$class->class_registrations};
+ my ($self, $name, $to_register) = @_;
+ my %reg = %{$self->class_registrations};
$reg{$name} = $to_register;
- $class->class_registrations(\%reg);
+ $self->class_registrations(\%reg);
+ $to_register->result_source->schema($self);
}
+=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 class
+
+ my $class = $schema->class('Foo');
+
+Shortcut to retrieve a single class by its registered name
+
+=cut
+
+sub class {
+ my ($self, $class) = @_;
+ return $self->class_registrations->{$class};
+}
+
+=head2 source
+
+ my $source = $schema->source('Foo');
+
+Returns the result source object for the registered name
+
+=cut
+
+sub source {
+ my ($self, $class) = @_;
+ return $self->class_registrations->{$class}->result_source;
+}
+
+=head2 resultset
+
+ my $rs = $schema->resultset('Foo');
+
+Returns the resultset for the registered name
+
+=cut
+
+sub resultset {
+ my ($self, $class) = @_;
+ return $self->class_registrations->{$class}->result_source->resultset;
+}
+
+
+=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 $comp_class"; # If it fails, assume the user fixed it
+ if ($@) {
+ die $@ unless $@ =~ /Can't locate/;
+ }
+ $class->register_class($comp => $comp_class);
+ }
}
}
+=head2 compose_connection <target> <@db_info>
+
+This is the most important method in this class. it takes a target namespace,
+as well as dbh connection info, and creates a L<DBIx::Class::DB> class as
+well as subclasses for each of your database classes in this namespace, using
+this connection.
+
+It will also setup a ->class method on the target class, which lets you
+resolve database classes based on the schema component name, for example
+
+ MyApp::DB->class('Foo') # returns MyApp::DB::Foo,
+ # which ISA MyApp::Schema::Foo
+
+This is the recommended API for accessing Schema generated classes, and
+using it might give you instant advantages with future versions of DBIC.
+
+WARNING: Loading components into Schema classes after compose_connection
+may not cause them to be seen by the classes in your target namespace due
+to the dispatch table approach used by Class::C3. If you do this you may find
+you need to call Class::C3->reinitialize() afterwards to get the behaviour
+you expect.
+
+=cut
+
sub compose_connection {
- my ($class, $target, @info) = @_;
- $class->setup_connection_class($target, @info);
+ my ($self, $target, @info) = @_;
+ my $conn_class = "${target}::_db";
+ $self->setup_connection_class($conn_class, @info);
+ my $schema = $self->compose_namespace($target, $conn_class);
+ $schema->storage($conn_class->storage);
+ foreach my $class ($schema->registered_classes) {
+ my $source = $class->result_source;
+ $source = $source->new($source);
+ $source->schema($schema);
+ $source->result_class($class);
+ $class->mk_classdata(result_source => $source);
+ $class->mk_classdata(resultset_instance => $source->resultset);
+ }
+ return $schema;
+}
+
+sub compose_namespace {
+ my ($class, $target, $base) = @_;
my %reg = %{ $class->class_registrations };
+ my %target;
+ my %map;
+ my $schema = bless({ }, $class);
while (my ($comp, $comp_class) = each %reg) {
my $target_class = "${target}::${comp}";
- $class->inject_base($target_class, $comp_class, $target);
+ $class->inject_base($target_class, $comp_class, ($base ? $base : ()));
+ @map{$comp, $comp_class} = ($target_class, $target_class);
+ }
+ $schema->class_registrations(\%map);
+ {
+ no strict 'refs';
+ *{"${target}::schema"} =
+ sub { $schema };
+ *{"${target}::class"} =
+ sub { shift->schema->class(@_) };
}
+ $base->class_resolver($target);
+ return $schema;
}
+=head2 setup_connection_class <$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');
- $target->load_components('DB');
+ $class->inject_base($target => 'DBIx::Class::DB');
+ #$target->load_components('DB');
$target->connection(@info);
}
-sub inject_base {
- my ($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