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 $class->ensure_class_loaded($comp_class);
267 $comp_class->source_name($comp) unless $comp_class->source_name;
269 push(@to_register, [ $comp_class->source_name, $comp_class ]);
273 Class::C3->reinitialize;
275 foreach my $to (@to_register) {
276 $class->register_class(@$to);
277 # if $class->can('result_source_instance');
281 =head2 load_namespaces
285 =item Arguments: %options?
289 This is an alternative to L</load_classes> above which assumes an alternative
290 layout for automatic class loading. It assumes that all ResultSource classes
291 to be loaded are underneath a sub- namespace of the schema called
292 "ResultSource", and any corresponding ResultSet classes to be underneath a
293 sub-namespace of the schema called "ResultSet".
295 You can change the namespaces checked for ResultSources and ResultSets via
296 the C<resultsource_namespace> and C<resultset_namespace> options, respectively.
298 Any source which does not have an explicitly-defined corresponding ResultSet
299 will have one created in the appropriate namespace for it, based on
300 L<DBIx::Class::ResultSet>. If you wish to change this default ResultSet
301 base class, you can do so via the C<default_resultset_base> option. (Your
302 custom default should, of course, be based on L<DBIx::Class::ResultSet>
305 This method requires L<Module::Find> to be installed on the system.
309 My::Schema->load_namespaces;
310 # loads My::Schema::ResultSource::CD, My::Schema::ResultSource::Artist,
311 # My::Schema::ResultSet::CD, etc...
313 My::Schema->load_namespaces(
314 resultsource_namespace => 'My::Schema::RSources',
315 resultset_namespace => 'My::Schema::RSets',
316 default_resultset_base => 'My::Schema::RSetBase',
318 # loads My::Schema::RSources::CD, My::Schema::RSources::Artist,
319 # My::Schema::RSets::CD, and if no such class exists on disk,
320 # creates My::Schema::RSets::Artist in memory based on the
321 # class My::Schema::RSetBase
325 sub load_namespaces {
326 my ($class, %args) = @_;
328 my $resultsource_namespace = $args{resultsource_namespace}
329 || ($class . '::ResultSource');
330 my $resultset_namespace = $args{resultset_namespace}
331 || ($class . '::ResultSet');
332 my $default_resultset_base = $args{default_resultset_base}
333 || 'DBIx::Class::ResultSet';
335 eval "require Module::Find";
336 $class->throw_exception("Couldn't load Module::Find ($@)") if $@;
338 my %sources = map { (substr($_, length "${resultsource_namespace}::"), $_) }
339 Module::Find::findallmod($resultsource_namespace);
341 my %resultsets = map { (substr($_, length "${resultset_namespace}::"), $_) }
342 Module::Find::findallmod($resultset_namespace);
346 no warnings qw/redefine/;
348 local *Class::C3::reinitialize = sub { };
349 foreach my $source (keys %sources) {
350 my $source_class = $sources{$source};
351 $class->ensure_class_loaded($source_class);
352 $source_class->source_name($source) unless $source_class->source_name;
353 if(!$source_class->resultset_class
354 || $source_class->resultset_class eq 'DBIx::Class::ResultSet') {
355 if(my $rs_class = delete $resultsets{$source}) {
356 $class->ensure_class_loaded($rs_class);
357 $source_class->resultset_class($rs_class);
360 my $rs_class = "$resultset_namespace\::$source";
361 @{"$rs_class\::ISA"} = ($default_resultset_base);
362 $source_class->resultset_class($rs_class);
366 push(@to_register, [ $source_class->source_name, $source_class ]);
370 foreach (keys %resultsets) {
371 warn "load_namespaces found ResultSet $_ with no "
372 . 'corresponding ResultSource';
375 Class::C3->reinitialize;
377 foreach my $to (@to_register) {
378 $class->register_class(@$to);
379 # if $class->can('result_source_instance');
383 =head2 compose_connection
387 =item Arguments: $target_namespace, @db_info
389 =item Return Value: $new_schema
393 Calls L<DBIx::Class::Schema/"compose_namespace"> to the target namespace,
394 calls L<DBIx::Class::Schema/connection> with @db_info on the new schema,
395 then injects the L<DBix::Class::ResultSetProxy> component and a
396 resultset_instance classdata entry on all the new classes, in order to support
397 $target_namespaces::$class->search(...) method calls.
399 This is primarily useful when you have a specific need for class method access
400 to a connection. In normal usage it is preferred to call
401 L<DBIx::Class::Schema/connect> and use the resulting schema object to operate
402 on L<DBIx::Class::ResultSet> objects with L<DBIx::Class::Schema/resultset> for
407 sub compose_connection {
408 my ($self, $target, @info) = @_;
409 my $base = 'DBIx::Class::ResultSetProxy';
410 eval "require ${base};";
411 $self->throw_exception
412 ("No arguments to load_classes and couldn't load ${base} ($@)")
415 if ($self eq $target) {
416 # Pathological case, largely caused by the docs on early C::M::DBIC::Plain
417 foreach my $moniker ($self->sources) {
418 my $source = $self->source($moniker);
419 my $class = $source->result_class;
420 $self->inject_base($class, $base);
421 $class->mk_classdata(resultset_instance => $source->resultset);
422 $class->mk_classdata(class_resolver => $self);
424 $self->connection(@info);
428 my $schema = $self->compose_namespace($target, $base);
431 *{"${target}::schema"} = sub { $schema };
434 $schema->connection(@info);
435 foreach my $moniker ($schema->sources) {
436 my $source = $schema->source($moniker);
437 my $class = $source->result_class;
438 #warn "$moniker $class $source ".$source->storage;
439 $class->mk_classdata(result_source_instance => $source);
440 $class->mk_classdata(resultset_instance => $source->resultset);
441 $class->mk_classdata(class_resolver => $schema);
446 =head2 compose_namespace
450 =item Arguments: $target_namespace, $additional_base_class?
452 =item Return Value: $new_schema
456 For each L<DBIx::Class::ResultSource> in the schema, this method creates a
457 class in the target namespace (e.g. $target_namespace::CD,
458 $target_namespace::Artist) that inherits from the corresponding classes
459 attached to the current schema.
461 It also attaches a corresponding L<DBIx::Class::ResultSource> object to the
462 new $schema object. If C<$additional_base_class> is given, the new composed
463 classes will inherit from first the corresponding classe from the current
464 schema then the base class.
466 For example, for a schema with My::Schema::CD and My::Schema::Artist classes,
468 $schema->compose_namespace('My::DB', 'Base::Class');
469 print join (', ', @My::DB::CD::ISA) . "\n";
470 print join (', ', @My::DB::Artist::ISA) ."\n";
472 will produce the output
474 My::Schema::CD, Base::Class
475 My::Schema::Artist, Base::Class
479 sub compose_namespace {
480 my ($self, $target, $base) = @_;
481 my %reg = %{ $self->source_registrations };
484 my $schema = $self->clone;
486 no warnings qw/redefine/;
487 local *Class::C3::reinitialize = sub { };
488 foreach my $moniker ($schema->sources) {
489 my $source = $schema->source($moniker);
490 my $target_class = "${target}::${moniker}";
492 $target_class => $source->result_class, ($base ? $base : ())
494 $source->result_class($target_class);
495 $target_class->result_source_instance($source)
496 if $target_class->can('result_source_instance');
499 Class::C3->reinitialize();
502 foreach my $meth (qw/class source resultset/) {
503 *{"${target}::${meth}"} =
504 sub { shift->schema->$meth(@_) };
510 =head2 setup_connection_class
514 =item Arguments: $target, @info
518 Sets up a database connection class to inject between the schema and the
519 subclasses that the schema creates.
523 sub setup_connection_class {
524 my ($class, $target, @info) = @_;
525 $class->inject_base($target => 'DBIx::Class::DB');
526 #$target->load_components('DB');
527 $target->connection(@info);
534 =item Arguments: @args
536 =item Return Value: $new_schema
540 Instantiates a new Storage object of type
541 L<DBIx::Class::Schema/"storage_type"> and passes the arguments to
542 $storage->connect_info. Sets the connection in-place on the schema. See
543 L<DBIx::Class::Storage::DBI/"connect_info"> for more information.
548 my ($self, @info) = @_;
549 return $self if !@info && $self->storage;
550 my $storage_class = $self->storage_type;
551 $storage_class = 'DBIx::Class::Storage'.$storage_class
552 if $storage_class =~ m/^::/;
553 eval "require ${storage_class};";
554 $self->throw_exception(
555 "No arguments to load_classes and couldn't load ${storage_class} ($@)"
557 my $storage = $storage_class->new;
558 $storage->connect_info(\@info);
559 $self->storage($storage);
567 =item Arguments: @info
569 =item Return Value: $new_schema
573 This is a convenience method. It is equivalent to calling
574 $schema->clone->connection(@info). See L</connection> and L</clone> for more
579 sub connect { shift->clone->connection(@_) }
583 Begins a transaction (does nothing if AutoCommit is off). Equivalent to
584 calling $schema->storage->txn_begin. See
585 L<DBIx::Class::Storage::DBI/"txn_begin"> for more information.
589 sub txn_begin { shift->storage->txn_begin }
593 Commits the current transaction. Equivalent to calling
594 $schema->storage->txn_commit. See L<DBIx::Class::Storage::DBI/"txn_commit">
595 for more information.
599 sub txn_commit { shift->storage->txn_commit }
603 Rolls back the current transaction. Equivalent to calling
604 $schema->storage->txn_rollback. See
605 L<DBIx::Class::Storage::DBI/"txn_rollback"> for more information.
609 sub txn_rollback { shift->storage->txn_rollback }
615 =item Arguments: C<$coderef>, @coderef_args?
617 =item Return Value: The return value of $coderef
621 Executes C<$coderef> with (optional) arguments C<@coderef_args> atomically,
622 returning its result (if any). If an exception is caught, a rollback is issued
623 and the exception is rethrown. If the rollback fails, (i.e. throws an
624 exception) an exception is thrown that includes a "Rollback failed" message.
628 my $author_rs = $schema->resultset('Author')->find(1);
629 my @titles = qw/Night Day It/;
632 # If any one of these fails, the entire transaction fails
633 $author_rs->create_related('books', {
635 }) foreach (@titles);
637 return $author->books;
642 $rs = $schema->txn_do($coderef);
645 if ($@) { # Transaction failed
646 die "something terrible has happened!" #
647 if ($@ =~ /Rollback failed/); # Rollback failed
649 deal_with_failed_transaction();
652 In a nested transaction (calling txn_do() from within a txn_do() coderef) only
653 the outermost transaction will issue a L<DBIx::Class::Schema/"txn_commit"> on
654 the Schema's storage, and txn_do() can be called in void, scalar and list
655 context and it will behave as expected.
660 my ($self, $coderef, @args) = @_;
662 $self->storage or $self->throw_exception
663 ('txn_do called on $schema without storage');
664 ref $coderef eq 'CODE' or $self->throw_exception
665 ('$coderef must be a CODE reference');
667 my (@return_values, $return_value);
669 $self->txn_begin; # If this throws an exception, no rollback is needed
671 my $wantarray = wantarray; # Need to save this since the context
672 # inside the eval{} block is independent
673 # of the context that called txn_do()
676 # Need to differentiate between scalar/list context to allow for
677 # returning a list in scalar context to get the size of the list
680 @return_values = $coderef->(@args);
681 } elsif (defined $wantarray) {
683 $return_value = $coderef->(@args);
699 my $rollback_error = $@;
700 my $exception_class = "DBIx::Class::Storage::NESTED_ROLLBACK_EXCEPTION";
701 $self->throw_exception($error) # propagate nested rollback
702 if $rollback_error =~ /$exception_class/;
704 $self->throw_exception(
705 "Transaction aborted: $error. Rollback failed: ${rollback_error}"
708 $self->throw_exception($error); # txn failed but rollback succeeded
712 return $wantarray ? @return_values : $return_value;
719 =item Return Value: $new_schema
723 Clones the schema and its associated result_source objects and returns the
730 my $clone = bless({ (ref $self ? %$self : ()) }, ref $self || $self);
731 foreach my $moniker ($self->sources) {
732 my $source = $self->source($moniker);
733 my $new = $source->new($source);
734 $clone->register_source($moniker => $new);
743 =item Arguments: $moniker, \@data;
747 Populates the source registered with the given moniker with the supplied data.
748 @data should be a list of listrefs -- the first containing column names, the
749 second matching values.
753 $schema->populate('Artist', [
754 [ qw/artistid name/ ],
755 [ 1, 'Popular Band' ],
763 my ($self, $name, $data) = @_;
764 my $rs = $self->resultset($name);
765 my @names = @{shift(@$data)};
767 foreach my $item (@$data) {
769 @create{@names} = @$item;
770 push(@created, $rs->create(\%create));
775 =head2 throw_exception
779 =item Arguments: $message
783 Throws an exception. Defaults to using L<Carp::Clan> to report errors from
788 sub throw_exception {
793 =head2 deploy (EXPERIMENTAL)
797 =item Arguments: $sqlt_args
801 Attempts to deploy the schema to the current storage using L<SQL::Translator>.
803 Note that this feature is currently EXPERIMENTAL and may not work correctly
804 across all databases, or fully handle complex relationships.
806 See L<SQL::Translator/METHODS> for a list of values for C<$sqlt_args>. The most
807 common value for this would be C<< { add_drop_table => 1, } >> to have the SQL
808 produced include a DROP TABLE statement for each table created.
813 my ($self, $sqltargs) = @_;
814 $self->throw_exception("Can't deploy without storage") unless $self->storage;
815 $self->storage->deploy($self, undef, $sqltargs);
818 =head2 create_ddl_dir (EXPERIMENTAL)
822 =item Arguments: \@databases, $version, $directory, $sqlt_args
826 Creates an SQL file based on the Schema, for each of the specified
827 database types, in the given directory.
829 Note that this feature is currently EXPERIMENTAL and may not work correctly
830 across all databases, or fully handle complex relationships.
838 $self->throw_exception("Can't create_ddl_dir without storage") unless $self->storage;
839 $self->storage->create_ddl_dir($self, @_);
842 =head2 ddl_filename (EXPERIMENTAL)
844 my $filename = $table->ddl_filename($type, $dir, $version)
846 Creates a filename for a SQL file based on the table class name. Not
847 intended for direct end user use.
853 my ($self, $type, $dir, $version) = @_;
855 my $filename = ref($self);
856 $filename =~ s/::/-/;
857 $filename = "$dir$filename-$version-$type.sql";
866 Matt S. Trout <mst@shadowcatsystems.co.uk>
870 You may distribute this code under the same terms as Perl itself.