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}; }
176 =item Arguments: $moniker
178 =item Return Value: $result_set
182 my $rs = $schema->resultset('DVD');
184 Returns the L<DBIx::Class::ResultSet> object for the registered moniker.
189 my ($self, $moniker) = @_;
190 return $self->source($moniker)->resultset;
197 =item Arguments: @classes?, { $namespace => [ @classes ] }+
201 With no arguments, this method uses L<Module::Find> to find all classes under
202 the schema's namespace. Otherwise, this method loads the classes you specify
203 (using L<use>), and registers them (using L</"register_class">).
205 It is possible to comment out classes with a leading C<#>, but note that perl
206 will think it's a mistake (trying to use a comment in a qw list), so you'll
207 need to add C<no warnings 'qw';> before your load_classes call.
211 My::Schema->load_classes(); # loads My::Schema::CD, My::Schema::Artist,
212 # etc. (anything under the My::Schema namespace)
214 # loads My::Schema::CD, My::Schema::Artist, Other::Namespace::Producer but
215 # not Other::Namespace::LinerNotes nor My::Schema::Track
216 My::Schema->load_classes(qw/ CD Artist #Track /, {
217 Other::Namespace => [qw/ Producer #LinerNotes /],
223 my ($class, @params) = @_;
228 foreach my $param (@params) {
229 if (ref $param eq 'ARRAY') {
230 # filter out commented entries
231 my @modules = grep { $_ !~ /^#/ } @$param;
233 push (@{$comps_for{$class}}, @modules);
235 elsif (ref $param eq 'HASH') {
236 # more than one namespace possible
237 for my $comp ( keys %$param ) {
238 # filter out commented entries
239 my @modules = grep { $_ !~ /^#/ } @{$param->{$comp}};
241 push (@{$comps_for{$comp}}, @modules);
245 # filter out commented entries
246 push (@{$comps_for{$class}}, $param) if $param !~ /^#/;
250 eval "require Module::Find;";
251 $class->throw_exception(
252 "No arguments to load_classes and couldn't load Module::Find ($@)"
254 my @comp = map { substr $_, length "${class}::" }
255 Module::Find::findallmod($class);
256 $comps_for{$class} = \@comp;
261 no warnings qw/redefine/;
262 local *Class::C3::reinitialize = sub { };
263 foreach my $prefix (keys %comps_for) {
264 foreach my $comp (@{$comps_for{$prefix}||[]}) {
265 my $comp_class = "${prefix}::${comp}";
266 eval "use $comp_class"; # If it fails, assume the user fixed it
268 $comp_class =~ s/::/\//g;
269 die $@ unless $@ =~ /Can't locate.+$comp_class\.pm\sin\s\@INC/;
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);
401 Class::C3->reinitialize();
404 foreach my $meth (qw/class source resultset/) {
405 *{"${target}::${meth}"} =
406 sub { shift->schema->$meth(@_) };
412 =head2 setup_connection_class
416 =item Arguments: $target, @info
420 Sets up a database connection class to inject between the schema and the
421 subclasses that the schema creates.
425 sub setup_connection_class {
426 my ($class, $target, @info) = @_;
427 $class->inject_base($target => 'DBIx::Class::DB');
428 #$target->load_components('DB');
429 $target->connection(@info);
436 =item Arguments: @args
438 =item Return Value: $new_schema
442 Instantiates a new Storage object of type
443 L<DBIx::Class::Schema/"storage_type"> and passes the arguments to
444 $storage->connect_info. Sets the connection in-place on the schema. See
445 L<DBIx::Class::Storage::DBI/"connect_info"> for more information.
450 my ($self, @info) = @_;
451 return $self if !@info && $self->storage;
452 my $storage_class = $self->storage_type;
453 $storage_class = 'DBIx::Class::Storage'.$storage_class
454 if $storage_class =~ m/^::/;
455 eval "require ${storage_class};";
456 $self->throw_exception(
457 "No arguments to load_classes and couldn't load ${storage_class} ($@)"
459 my $storage = $storage_class->new;
460 $storage->connect_info(\@info);
461 $self->storage($storage);
469 =item Arguments: @info
471 =item Return Value: $new_schema
475 This is a convenience method. It is equivalent to calling
476 $schema->clone->connection(@info). See L</connection> and L</clone> for more
481 sub connect { shift->clone->connection(@_) }
485 Begins a transaction (does nothing if AutoCommit is off). Equivalent to
486 calling $schema->storage->txn_begin. See
487 L<DBIx::Class::Storage::DBI/"txn_begin"> for more information.
491 sub txn_begin { shift->storage->txn_begin }
495 Commits the current transaction. Equivalent to calling
496 $schema->storage->txn_commit. See L<DBIx::Class::Storage::DBI/"txn_commit">
497 for more information.
501 sub txn_commit { shift->storage->txn_commit }
505 Rolls back the current transaction. Equivalent to calling
506 $schema->storage->txn_rollback. See
507 L<DBIx::Class::Storage::DBI/"txn_rollback"> for more information.
511 sub txn_rollback { shift->storage->txn_rollback }
517 =item Arguments: C<$coderef>, @coderef_args?
519 =item Return Value: The return value of $coderef
523 Executes C<$coderef> with (optional) arguments C<@coderef_args> atomically,
524 returning its result (if any). If an exception is caught, a rollback is issued
525 and the exception is rethrown. If the rollback fails, (i.e. throws an
526 exception) an exception is thrown that includes a "Rollback failed" message.
530 my $author_rs = $schema->resultset('Author')->find(1);
533 my ($author, @titles) = @_;
535 # If any one of these fails, the entire transaction fails
536 $author->create_related('books', {
538 }) foreach (@titles);
540 return $author->books;
545 $rs = $schema->txn_do($coderef, $author_rs, qw/Night Day It/);
550 if ($error =~ /Rollback failed/) {
551 die "something terrible has happened!";
553 deal_with_failed_transaction();
557 In a nested transaction (calling txn_do() from within a txn_do() coderef) only
558 the outermost transaction will issue a L<DBIx::Class::Schema/"txn_commit"> on
559 the Schema's storage, and txn_do() can be called in void, scalar and list
560 context and it will behave as expected.
565 my ($self, $coderef, @args) = @_;
567 ref $self or $self->throw_exception
568 ('Cannot execute txn_do as a class method');
569 ref $coderef eq 'CODE' or $self->throw_exception
570 ('$coderef must be a CODE reference');
572 my (@return_values, $return_value);
574 $self->txn_begin; # If this throws an exception, no rollback is needed
576 my $wantarray = wantarray; # Need to save this since the context
577 # inside the eval{} block is independent
578 # of the context that called txn_do()
581 # Need to differentiate between scalar/list context to allow for
582 # returning a list in scalar context to get the size of the list
585 @return_values = $coderef->(@args);
586 } elsif (defined $wantarray) {
588 $return_value = $coderef->(@args);
604 my $rollback_error = $@;
605 my $exception_class = "DBIx::Class::Storage::NESTED_ROLLBACK_EXCEPTION";
606 $self->throw_exception($error) # propagate nested rollback
607 if $rollback_error =~ /$exception_class/;
609 $self->throw_exception(
610 "Transaction aborted: $error. Rollback failed: ${rollback_error}"
613 $self->throw_exception($error); # txn failed but rollback succeeded
617 return $wantarray ? @return_values : $return_value;
624 =item Return Value: $new_schema
628 Clones the schema and its associated result_source objects and returns the
635 my $clone = bless({ (ref $self ? %$self : ()) }, ref $self || $self);
636 foreach my $moniker ($self->sources) {
637 my $source = $self->source($moniker);
638 my $new = $source->new($source);
639 $clone->register_source($moniker => $new);
648 =item Arguments: $moniker, \@data;
652 Populates the source registered with the given moniker with the supplied data.
653 @data should be a list of listrefs -- the first containing column names, the
654 second matching values.
658 $schema->populate('Artist', [
659 [ qw/artistid name/ ],
660 [ 1, 'Popular Band' ],
668 my ($self, $name, $data) = @_;
669 my $rs = $self->resultset($name);
670 my @names = @{shift(@$data)};
672 foreach my $item (@$data) {
674 @create{@names} = @$item;
675 push(@created, $rs->create(\%create));
680 =head2 throw_exception
684 =item Arguments: $message
688 Throws an exception. Defaults to using L<Carp::Clan> to report errors from
693 sub throw_exception {
698 =head2 deploy (EXPERIMENTAL)
702 =item Arguments: $sqlt_args
706 Attempts to deploy the schema to the current storage using L<SQL::Translator>.
708 Note that this feature is currently EXPERIMENTAL and may not work correctly
709 across all databases, or fully handle complex relationships.
714 my ($self, $sqltargs) = @_;
715 $self->throw_exception("Can't deploy without storage") unless $self->storage;
716 $self->storage->deploy($self, undef, $sqltargs);
719 =head2 create_ddl_dir (EXPERIMENTAL)
723 =item Arguments: \@databases, $version, $directory, $sqlt_args
727 Creates an SQL file based on the Schema, for each of the specified
728 database types, in the given directory.
730 Note that this feature is currently EXPERIMENTAL and may not work correctly
731 across all databases, or fully handle complex relationships.
739 $self->throw_exception("Can't create_ddl_dir without storage") unless $self->storage;
740 $self->storage->create_ddl_dir($self, @_);
745 my ($self, $type, $dir, $version) = @_;
747 my $filename = ref($self);
748 $filename =~ s/^.*:://;
749 $filename = "$dir$filename-$version-$type.sql";
758 Matt S. Trout <mst@shadowcatsystems.co.uk>
762 You may distribute this code under the same terms as Perl itself.