1 package DBIx::Class::Schema;
6 use Carp::Clan qw/^DBIx::Class/;
7 use Scalar::Util qw/weaken/;
9 use base qw/DBIx::Class/;
11 __PACKAGE__->mk_classdata('class_mappings' => {});
12 __PACKAGE__->mk_classdata('source_registrations' => {});
13 __PACKAGE__->mk_classdata('storage_type' => '::DBI');
14 __PACKAGE__->mk_classdata('storage');
18 DBIx::Class::Schema - composable schemas
22 package Library::Schema;
23 use base qw/DBIx::Class::Schema/;
25 # load Library::Schema::CD, Library::Schema::Book, Library::Schema::DVD
26 __PACKAGE__->load_classes(qw/CD Book DVD/);
28 package Library::Schema::CD;
29 use base qw/DBIx::Class/;
30 __PACKAGE__->load_components(qw/PK::Auto Core/); # for example
31 __PACKAGE__->table('cd');
33 # Elsewhere in your code:
34 my $schema1 = Library::Schema->connect(
41 my $schema2 = Library::Schema->connect($coderef_returning_dbh);
43 # fetch objects using Library::Schema::DVD
44 my $resultset = $schema1->resultset('DVD')->search( ... );
45 my @dvd_objects = $schema2->resultset('DVD')->search( ... );
49 Creates database classes based on a schema. This is the recommended way to
50 use L<DBIx::Class> and allows you to use more than one concurrent connection
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.
63 =item Arguments: $moniker, $component_class
67 Registers a class which isa DBIx::Class::ResultSourceProxy. Equivalent to
70 $schema->register_source($moniker, $component_class->result_source_instance);
75 my ($self, $moniker, $to_register) = @_;
76 $self->register_source($moniker => $to_register->result_source_instance);
79 =head2 register_source
83 =item Arguments: $moniker, $result_source
87 Registers the L<DBIx::Class::ResultSource> in the schema with the given
93 my ($self, $moniker, $source) = @_;
94 my %reg = %{$self->source_registrations};
95 $reg{$moniker} = $source;
96 $self->source_registrations(\%reg);
97 $source->schema($self);
98 weaken($source->{schema}) if ref($self);
99 if ($source->result_class) {
100 my %map = %{$self->class_mappings};
101 $map{$source->result_class} = $moniker;
102 $self->class_mappings(\%map);
110 =item Arguments: $moniker
112 =item Return Value: $classname
116 Retrieves the result class name for the given moniker. For example:
118 my $class = $schema->class('CD');
123 my ($self, $moniker) = @_;
124 return $self->source($moniker)->result_class;
131 =item Arguments: $moniker
133 =item Return Value: $result_source
137 my $source = $schema->source('Book');
139 Returns the L<DBIx::Class::ResultSource> object for the registered moniker.
144 my ($self, $moniker) = @_;
145 my $sreg = $self->source_registrations;
146 return $sreg->{$moniker} if exists $sreg->{$moniker};
148 # if we got here, they probably passed a full class name
149 my $mapped = $self->class_mappings->{$moniker};
150 $self->throw_exception("Can't find source for ${moniker}")
151 unless $mapped && exists $sreg->{$mapped};
152 return $sreg->{$mapped};
159 =item Return Value: @source_monikers
163 Returns the source monikers of all source registrations on this schema.
166 my @source_monikers = $schema->sources;
170 sub sources { return keys %{shift->source_registrations}; }
174 my $storage = $schema->storage;
176 Returns the L<DBIx::Class::Storage> object for this Schema.
182 =item Arguments: $moniker
184 =item Return Value: $result_set
188 my $rs = $schema->resultset('DVD');
190 Returns the L<DBIx::Class::ResultSet> object for the registered moniker.
195 my ($self, $moniker) = @_;
196 return $self->source($moniker)->resultset;
203 =item Arguments: @classes?, { $namespace => [ @classes ] }+
207 With no arguments, this method uses L<Module::Find> to find all classes under
208 the schema's namespace. Otherwise, this method loads the classes you specify
209 (using L<use>), and registers them (using L</"register_class">).
211 It is possible to comment out classes with a leading C<#>, but note that perl
212 will think it's a mistake (trying to use a comment in a qw list), so you'll
213 need to add C<no warnings 'qw';> before your load_classes call.
217 My::Schema->load_classes(); # loads My::Schema::CD, My::Schema::Artist,
218 # etc. (anything under the My::Schema namespace)
220 # loads My::Schema::CD, My::Schema::Artist, Other::Namespace::Producer but
221 # not Other::Namespace::LinerNotes nor My::Schema::Track
222 My::Schema->load_classes(qw/ CD Artist #Track /, {
223 Other::Namespace => [qw/ Producer #LinerNotes /],
229 my ($class, @params) = @_;
234 foreach my $param (@params) {
235 if (ref $param eq 'ARRAY') {
236 # filter out commented entries
237 my @modules = grep { $_ !~ /^#/ } @$param;
239 push (@{$comps_for{$class}}, @modules);
241 elsif (ref $param eq 'HASH') {
242 # more than one namespace possible
243 for my $comp ( keys %$param ) {
244 # filter out commented entries
245 my @modules = grep { $_ !~ /^#/ } @{$param->{$comp}};
247 push (@{$comps_for{$comp}}, @modules);
251 # filter out commented entries
252 push (@{$comps_for{$class}}, $param) if $param !~ /^#/;
256 eval "require Module::Find;";
257 $class->throw_exception(
258 "No arguments to load_classes and couldn't load Module::Find ($@)"
260 my @comp = map { substr $_, length "${class}::" }
261 Module::Find::findallmod($class);
262 $comps_for{$class} = \@comp;
267 no warnings qw/redefine/;
268 local *Class::C3::reinitialize = sub { };
269 foreach my $prefix (keys %comps_for) {
270 foreach my $comp (@{$comps_for{$prefix}||[]}) {
271 my $comp_class = "${prefix}::${comp}";
272 $class->ensure_class_loaded($comp_class);
273 $comp_class->source_name($comp) unless $comp_class->source_name;
275 push(@to_register, [ $comp_class->source_name, $comp_class ]);
279 Class::C3->reinitialize;
281 foreach my $to (@to_register) {
282 $class->register_class(@$to);
283 # if $class->can('result_source_instance');
287 =head2 compose_connection
291 =item Arguments: $target_namespace, @db_info
293 =item Return Value: $new_schema
297 Calls L<DBIx::Class::Schema/"compose_namespace"> to the target namespace,
298 calls L<DBIx::Class::Schema/connection> with @db_info on the new schema,
299 then injects the L<DBix::Class::ResultSetProxy> component and a
300 resultset_instance classdata entry on all the new classes, in order to support
301 $target_namespaces::$class->search(...) method calls.
303 This is primarily useful when you have a specific need for class method access
304 to a connection. In normal usage it is preferred to call
305 L<DBIx::Class::Schema/connect> and use the resulting schema object to operate
306 on L<DBIx::Class::ResultSet> objects with L<DBIx::Class::Schema/resultset> for
311 sub compose_connection {
312 my ($self, $target, @info) = @_;
313 my $base = 'DBIx::Class::ResultSetProxy';
314 eval "require ${base};";
315 $self->throw_exception
316 ("No arguments to load_classes and couldn't load ${base} ($@)")
319 if ($self eq $target) {
320 # Pathological case, largely caused by the docs on early C::M::DBIC::Plain
321 foreach my $moniker ($self->sources) {
322 my $source = $self->source($moniker);
323 my $class = $source->result_class;
324 $self->inject_base($class, $base);
325 $class->mk_classdata(resultset_instance => $source->resultset);
326 $class->mk_classdata(class_resolver => $self);
328 $self->connection(@info);
332 my $schema = $self->compose_namespace($target, $base);
335 *{"${target}::schema"} = sub { $schema };
338 $schema->connection(@info);
339 foreach my $moniker ($schema->sources) {
340 my $source = $schema->source($moniker);
341 my $class = $source->result_class;
342 #warn "$moniker $class $source ".$source->storage;
343 $class->mk_classdata(result_source_instance => $source);
344 $class->mk_classdata(resultset_instance => $source->resultset);
345 $class->mk_classdata(class_resolver => $schema);
350 =head2 compose_namespace
354 =item Arguments: $target_namespace, $additional_base_class?
356 =item Return Value: $new_schema
360 For each L<DBIx::Class::ResultSource> in the schema, this method creates a
361 class in the target namespace (e.g. $target_namespace::CD,
362 $target_namespace::Artist) that inherits from the corresponding classes
363 attached to the current schema.
365 It also attaches a corresponding L<DBIx::Class::ResultSource> object to the
366 new $schema object. If C<$additional_base_class> is given, the new composed
367 classes will inherit from first the corresponding classe from the current
368 schema then the base class.
370 For example, for a schema with My::Schema::CD and My::Schema::Artist classes,
372 $schema->compose_namespace('My::DB', 'Base::Class');
373 print join (', ', @My::DB::CD::ISA) . "\n";
374 print join (', ', @My::DB::Artist::ISA) ."\n";
376 will produce the output
378 My::Schema::CD, Base::Class
379 My::Schema::Artist, Base::Class
383 sub compose_namespace {
384 my ($self, $target, $base) = @_;
385 my %reg = %{ $self->source_registrations };
388 my $schema = $self->clone;
390 no warnings qw/redefine/;
391 local *Class::C3::reinitialize = sub { };
392 foreach my $moniker ($schema->sources) {
393 my $source = $schema->source($moniker);
394 my $target_class = "${target}::${moniker}";
396 $target_class => $source->result_class, ($base ? $base : ())
398 $source->result_class($target_class);
399 $target_class->result_source_instance($source)
400 if $target_class->can('result_source_instance');
403 Class::C3->reinitialize();
406 foreach my $meth (qw/class source resultset/) {
407 *{"${target}::${meth}"} =
408 sub { shift->schema->$meth(@_) };
414 =head2 setup_connection_class
418 =item Arguments: $target, @info
422 Sets up a database connection class to inject between the schema and the
423 subclasses that the schema creates.
427 sub setup_connection_class {
428 my ($class, $target, @info) = @_;
429 $class->inject_base($target => 'DBIx::Class::DB');
430 #$target->load_components('DB');
431 $target->connection(@info);
438 =item Arguments: @args
440 =item Return Value: $new_schema
444 Instantiates a new Storage object of type
445 L<DBIx::Class::Schema/"storage_type"> and passes the arguments to
446 $storage->connect_info. Sets the connection in-place on the schema. See
447 L<DBIx::Class::Storage::DBI/"connect_info"> for more information.
452 my ($self, @info) = @_;
453 return $self if !@info && $self->storage;
454 my $storage_class = $self->storage_type;
455 $storage_class = 'DBIx::Class::Storage'.$storage_class
456 if $storage_class =~ m/^::/;
457 eval "require ${storage_class};";
458 $self->throw_exception(
459 "No arguments to load_classes and couldn't load ${storage_class} ($@)"
461 my $storage = $storage_class->new;
462 $storage->connect_info(\@info);
463 $self->storage($storage);
471 =item Arguments: @info
473 =item Return Value: $new_schema
477 This is a convenience method. It is equivalent to calling
478 $schema->clone->connection(@info). See L</connection> and L</clone> for more
483 sub connect { shift->clone->connection(@_) }
487 Begins a transaction (does nothing if AutoCommit is off). Equivalent to
488 calling $schema->storage->txn_begin. See
489 L<DBIx::Class::Storage::DBI/"txn_begin"> for more information.
493 sub txn_begin { shift->storage->txn_begin }
497 Commits the current transaction. Equivalent to calling
498 $schema->storage->txn_commit. See L<DBIx::Class::Storage::DBI/"txn_commit">
499 for more information.
503 sub txn_commit { shift->storage->txn_commit }
507 Rolls back the current transaction. Equivalent to calling
508 $schema->storage->txn_rollback. See
509 L<DBIx::Class::Storage::DBI/"txn_rollback"> for more information.
513 sub txn_rollback { shift->storage->txn_rollback }
519 =item Arguments: C<$coderef>, @coderef_args?
521 =item Return Value: The return value of $coderef
525 Executes C<$coderef> with (optional) arguments C<@coderef_args> atomically,
526 returning its result (if any). If an exception is caught, a rollback is issued
527 and the exception is rethrown. If the rollback fails, (i.e. throws an
528 exception) an exception is thrown that includes a "Rollback failed" message.
532 my $author_rs = $schema->resultset('Author')->find(1);
533 my @titles = qw/Night Day It/;
536 # If any one of these fails, the entire transaction fails
537 $author_rs->create_related('books', {
539 }) foreach (@titles);
541 return $author->books;
546 $rs = $schema->txn_do($coderef);
549 if ($@) { # Transaction failed
550 die "something terrible has happened!" #
551 if ($@ =~ /Rollback failed/); # Rollback failed
553 deal_with_failed_transaction();
556 In a nested transaction (calling txn_do() from within a txn_do() coderef) only
557 the outermost transaction will issue a L<DBIx::Class::Schema/"txn_commit"> on
558 the Schema's storage, and txn_do() can be called in void, scalar and list
559 context and it will behave as expected.
564 my ($self, $coderef, @args) = @_;
566 $self->storage or $self->throw_exception
567 ('txn_do called on $schema without storage');
568 ref $coderef eq 'CODE' or $self->throw_exception
569 ('$coderef must be a CODE reference');
571 my (@return_values, $return_value);
573 $self->txn_begin; # If this throws an exception, no rollback is needed
575 my $wantarray = wantarray; # Need to save this since the context
576 # inside the eval{} block is independent
577 # of the context that called txn_do()
580 # Need to differentiate between scalar/list context to allow for
581 # returning a list in scalar context to get the size of the list
584 @return_values = $coderef->(@args);
585 } elsif (defined $wantarray) {
587 $return_value = $coderef->(@args);
603 my $rollback_error = $@;
604 my $exception_class = "DBIx::Class::Storage::NESTED_ROLLBACK_EXCEPTION";
605 $self->throw_exception($error) # propagate nested rollback
606 if $rollback_error =~ /$exception_class/;
608 $self->throw_exception(
609 "Transaction aborted: $error. Rollback failed: ${rollback_error}"
612 $self->throw_exception($error); # txn failed but rollback succeeded
616 return $wantarray ? @return_values : $return_value;
623 =item Return Value: $new_schema
627 Clones the schema and its associated result_source objects and returns the
634 my $clone = { (ref $self ? %$self : ()) };
635 bless $clone, (ref $self || $self);
637 foreach my $moniker ($self->sources) {
638 my $source = $self->source($moniker);
639 my $new = $source->new($source);
640 $clone->register_source($moniker => $new);
649 =item Arguments: $moniker, \@data;
653 Populates the source registered with the given moniker with the supplied data.
654 @data should be a list of listrefs -- the first containing column names, the
655 second matching values.
659 $schema->populate('Artist', [
660 [ qw/artistid name/ ],
661 [ 1, 'Popular Band' ],
669 my ($self, $name, $data) = @_;
670 my $rs = $self->resultset($name);
671 my @names = @{shift(@$data)};
673 foreach my $item (@$data) {
675 @create{@names} = @$item;
676 push(@created, $rs->create(\%create));
681 =head2 throw_exception
685 =item Arguments: $message
689 Throws an exception. Defaults to using L<Carp::Clan> to report errors from
694 sub throw_exception {
699 =head2 deploy (EXPERIMENTAL)
703 =item Arguments: $sqlt_args, $dir
707 Attempts to deploy the schema to the current storage using L<SQL::Translator>.
709 Note that this feature is currently EXPERIMENTAL and may not work correctly
710 across all databases, or fully handle complex relationships.
712 See L<SQL::Translator/METHODS> for a list of values for C<$sqlt_args>. The most
713 common value for this would be C<< { add_drop_table => 1, } >> to have the SQL
714 produced include a DROP TABLE statement for each table created.
719 my ($self, $sqltargs, $dir) = @_;
720 $self->throw_exception("Can't deploy without storage") unless $self->storage;
721 $self->storage->deploy($self, undef, $sqltargs, $dir);
724 =head2 create_ddl_dir (EXPERIMENTAL)
728 =item Arguments: \@databases, $version, $directory, $sqlt_args
732 Creates an SQL file based on the Schema, for each of the specified
733 database types, in the given directory.
735 Note that this feature is currently EXPERIMENTAL and may not work correctly
736 across all databases, or fully handle complex relationships.
743 $self->throw_exception("Can't create_ddl_dir without storage") unless $self->storage;
744 $self->storage->create_ddl_dir($self, @_);
747 =head2 ddl_filename (EXPERIMENTAL)
749 my $filename = $table->ddl_filename($type, $dir, $version)
751 Creates a filename for a SQL file based on the table class name. Not
752 intended for direct end user use.
757 my ($self, $type, $dir, $version) = @_;
759 my $filename = ref($self);
760 $filename =~ s/::/-/;
761 $filename = "$dir$filename-$version-$type.sql";
770 Matt S. Trout <mst@shadowcatsystems.co.uk>
774 You may distribute this code under the same terms as Perl itself.