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');
15 __PACKAGE__->mk_classdata('exception_action');
19 DBIx::Class::Schema - composable schemas
23 package Library::Schema;
24 use base qw/DBIx::Class::Schema/;
26 # load Library::Schema::CD, Library::Schema::Book, Library::Schema::DVD
27 __PACKAGE__->load_classes(qw/CD Book DVD/);
29 package Library::Schema::CD;
30 use base qw/DBIx::Class/;
31 __PACKAGE__->load_components(qw/PK::Auto Core/); # for example
32 __PACKAGE__->table('cd');
34 # Elsewhere in your code:
35 my $schema1 = Library::Schema->connect(
42 my $schema2 = Library::Schema->connect($coderef_returning_dbh);
44 # fetch objects using Library::Schema::DVD
45 my $resultset = $schema1->resultset('DVD')->search( ... );
46 my @dvd_objects = $schema2->resultset('DVD')->search( ... );
50 Creates database classes based on a schema. This is the recommended way to
51 use L<DBIx::Class> and allows you to use more than one concurrent connection
54 NB: If you're used to L<Class::DBI> it's worth reading the L</SYNOPSIS>
55 carefully, as DBIx::Class does things a little differently. Note in
56 particular which module inherits off which.
64 =item Arguments: $moniker, $component_class
68 Registers a class which isa DBIx::Class::ResultSourceProxy. Equivalent to
71 $schema->register_source($moniker, $component_class->result_source_instance);
76 my ($self, $moniker, $to_register) = @_;
77 $self->register_source($moniker => $to_register->result_source_instance);
80 =head2 register_source
84 =item Arguments: $moniker, $result_source
88 Registers the L<DBIx::Class::ResultSource> in the schema with the given
94 my ($self, $moniker, $source) = @_;
95 my %reg = %{$self->source_registrations};
96 $reg{$moniker} = $source;
97 $self->source_registrations(\%reg);
98 $source->schema($self);
99 weaken($source->{schema}) if ref($self);
100 if ($source->result_class) {
101 my %map = %{$self->class_mappings};
102 $map{$source->result_class} = $moniker;
103 $self->class_mappings(\%map);
111 =item Arguments: $moniker
113 =item Return Value: $classname
117 Retrieves the result class name for the given moniker. For example:
119 my $class = $schema->class('CD');
124 my ($self, $moniker) = @_;
125 return $self->source($moniker)->result_class;
132 =item Arguments: $moniker
134 =item Return Value: $result_source
138 my $source = $schema->source('Book');
140 Returns the L<DBIx::Class::ResultSource> object for the registered moniker.
145 my ($self, $moniker) = @_;
146 my $sreg = $self->source_registrations;
147 return $sreg->{$moniker} if exists $sreg->{$moniker};
149 # if we got here, they probably passed a full class name
150 my $mapped = $self->class_mappings->{$moniker};
151 $self->throw_exception("Can't find source for ${moniker}")
152 unless $mapped && exists $sreg->{$mapped};
153 return $sreg->{$mapped};
160 =item Return Value: @source_monikers
164 Returns the source monikers of all source registrations on this schema.
167 my @source_monikers = $schema->sources;
171 sub sources { return keys %{shift->source_registrations}; }
177 =item Arguments: $moniker
179 =item Return Value: $result_set
183 my $rs = $schema->resultset('DVD');
185 Returns the L<DBIx::Class::ResultSet> object for the registered moniker.
190 my ($self, $moniker) = @_;
191 return $self->source($moniker)->resultset;
198 =item Arguments: @classes?, { $namespace => [ @classes ] }+
202 With no arguments, this method uses L<Module::Find> to find all classes under
203 the schema's namespace. Otherwise, this method loads the classes you specify
204 (using L<use>), and registers them (using L</"register_class">).
206 It is possible to comment out classes with a leading C<#>, but note that perl
207 will think it's a mistake (trying to use a comment in a qw list), so you'll
208 need to add C<no warnings 'qw';> before your load_classes call.
212 My::Schema->load_classes(); # loads My::Schema::CD, My::Schema::Artist,
213 # etc. (anything under the My::Schema namespace)
215 # loads My::Schema::CD, My::Schema::Artist, Other::Namespace::Producer but
216 # not Other::Namespace::LinerNotes nor My::Schema::Track
217 My::Schema->load_classes(qw/ CD Artist #Track /, {
218 Other::Namespace => [qw/ Producer #LinerNotes /],
224 my ($class, @params) = @_;
229 foreach my $param (@params) {
230 if (ref $param eq 'ARRAY') {
231 # filter out commented entries
232 my @modules = grep { $_ !~ /^#/ } @$param;
234 push (@{$comps_for{$class}}, @modules);
236 elsif (ref $param eq 'HASH') {
237 # more than one namespace possible
238 for my $comp ( keys %$param ) {
239 # filter out commented entries
240 my @modules = grep { $_ !~ /^#/ } @{$param->{$comp}};
242 push (@{$comps_for{$comp}}, @modules);
246 # filter out commented entries
247 push (@{$comps_for{$class}}, $param) if $param !~ /^#/;
251 eval "require Module::Find;";
252 $class->throw_exception(
253 "No arguments to load_classes and couldn't load Module::Find ($@)"
255 my @comp = map { substr $_, length "${class}::" }
256 Module::Find::findallmod($class);
257 $comps_for{$class} = \@comp;
262 no warnings qw/redefine/;
263 local *Class::C3::reinitialize = sub { };
264 foreach my $prefix (keys %comps_for) {
265 foreach my $comp (@{$comps_for{$prefix}||[]}) {
266 my $comp_class = "${prefix}::${comp}";
267 $class->ensure_class_loaded($comp_class);
268 $comp_class->source_name($comp) unless $comp_class->source_name;
270 push(@to_register, [ $comp_class->source_name, $comp_class ]);
274 Class::C3->reinitialize;
276 foreach my $to (@to_register) {
277 $class->register_class(@$to);
278 # if $class->can('result_source_instance');
282 =head2 load_namespaces
286 =item Arguments: %options?
290 This is an alternative to L</load_classes> above which assumes an alternative
291 layout for automatic class loading. It assumes that all ResultSource classes
292 to be loaded are underneath a sub-namespace of the schema called
293 "ResultSource", any corresponding ResultSet classes to be underneath a
294 sub-namespace of the schema called "ResultSet", and any corresponing
295 Result classes to be underneath a sub-namespace of the schema called "Result".
297 All of those sub-namespaces are configurable if you don't like the defaults,
298 via the options C<resultsource_namespace>, C<resultset_namespace>, and
299 C<result_namespace>, respectively.
301 If (and only if) you specify the option C<default_resultset_base>, any found
302 ResultSource classes that have no manually-created corresponding ResultSet
303 class will have one created for them in memory in the C<resultset_namespace>,
304 based on C<default_resultset_base>.
306 All of the namespace and classname options to this method are relative to
307 the schema classname by default. To specify a fully-qualified name, prefix
308 it with a literal C<+>.
310 This method requires L<Module::Find> to be installed on the system.
314 # load My::Schema::ResultSource::CD, My::Schema::ResultSource::Artist,
315 # My::Schema::ResultSet::CD, etc...
316 My::Schema->load_namespaces;
318 # Override everything...
319 My::Schema->load_namespaces(
320 resultsource_namespace => 'RSources',
321 resultset_namespace => 'RSets',
322 result_namespace => 'Results',
323 default_resultset_base => 'RSetBase',
325 # ... and if there is a My::Schema::RSources::Foo, but no matching
326 # My::Schema::RSets::Foo, then My::Schema::RSets::Foo will be created
327 # for you in memory, based on My::Schema::RSetBase
329 # Put things in other namespaces
330 My::Schema->load_namespaces(
331 resultsource_namespace => '+Some::Place::RSources',
332 resultset_namespace => '+Another::Place::RSets',
333 result_namespace => '+Crazy::Stuff::Results',
334 default_resultset_base => '+You::Never::Know::RSetBase',
340 sub load_namespaces {
341 my ($class, %args) = @_;
343 my $resultsource_namespace = $args{resultsource_namespace} || 'ResultSource';
344 my $resultset_namespace = $args{resultset_namespace} || 'ResultSet';
345 my $result_namespace = $args{result_namespace} || 'Result';
346 my $default_resultset_base = $args{default_resultset_base};
348 foreach ($resultsource_namespace, $resultset_namespace,
349 $result_namespace, $default_resultset_base) {
351 $_ = $class . '::' . $_ if !s/^\+//;
354 eval "require Module::Find";
355 $class->throw_exception("Couldn't load Module::Find ($@)") if $@;
357 my %sources = map { (substr($_, length "${resultsource_namespace}::"), $_) }
358 Module::Find::findallmod($resultsource_namespace);
360 my %resultsets = map { (substr($_, length "${resultset_namespace}::"), $_) }
361 Module::Find::findallmod($resultset_namespace);
363 my %results = map { (substr($_, length "${result_namespace}::"), $_) }
364 Module::Find::findallmod($result_namespace);
368 no warnings qw/redefine/;
369 local *Class::C3::reinitialize = sub { };
370 use warnings qw/redefine/;
372 foreach my $source (keys %sources) {
373 my $source_class = $sources{$source};
374 $class->ensure_class_loaded($source_class);
375 $source_class->source_name($source) unless $source_class->source_name;
377 my $rs_class = delete $resultsets{$source};
378 my $rs_set = $source_class->resultset_class;
379 if(!$rs_set || $rs_set eq 'DBIx::Class::ResultSet') {
381 $class->ensure_class_loaded($rs_class);
382 $source_class->resultset_class($rs_class);
384 elsif($default_resultset_base) {
385 $class->ensure_class_loaded($default_resultset_base);
386 $rs_class = "$resultset_namespace\::$source";
387 { no strict qw/refs/; @{"$rs_class\::ISA"} = ($default_resultset_base); }
388 $source_class->resultset_class($rs_class);
391 elsif($rs_set && $rs_class) {
392 warn "We found ResultSet class '$rs_class' for '$source', but it seems "
393 . "that you had already set '$source' to use '$rs_set' instead";
396 my $r_class = delete $results{$source};
398 my $r_set = $source_class->result_class;
399 if(!$r_set || $r_set eq $sources{$source}) {
400 $class->ensure_class_loaded($r_class);
401 $source_class->result_class($r_class);
404 warn "We found Result class '$r_class' for '$source', but it seems "
405 . "that you had already set '$source' to use '$r_set' instead";
409 push(@to_register, [ $source_class->source_name, $source_class ]);
413 foreach (sort keys %resultsets) {
414 warn "load_namespaces found ResultSet class $_ with no "
415 . 'corresponding ResultSource';
418 foreach (sort keys %results) {
419 warn "load_namespaces found Result class $_ with no "
420 . 'corresponding ResultSource';
423 Class::C3->reinitialize;
424 $class->register_class(@$_) for (@to_register);
429 =head2 compose_connection
433 =item Arguments: $target_namespace, @db_info
435 =item Return Value: $new_schema
439 Calls L<DBIx::Class::Schema/"compose_namespace"> to the target namespace,
440 calls L<DBIx::Class::Schema/connection> with @db_info on the new schema,
441 then injects the L<DBix::Class::ResultSetProxy> component and a
442 resultset_instance classdata entry on all the new classes, in order to support
443 $target_namespaces::$class->search(...) method calls.
445 This is primarily useful when you have a specific need for class method access
446 to a connection. In normal usage it is preferred to call
447 L<DBIx::Class::Schema/connect> and use the resulting schema object to operate
448 on L<DBIx::Class::ResultSet> objects with L<DBIx::Class::Schema/resultset> for
453 sub compose_connection {
454 my ($self, $target, @info) = @_;
455 my $base = 'DBIx::Class::ResultSetProxy';
456 eval "require ${base};";
457 $self->throw_exception
458 ("No arguments to load_classes and couldn't load ${base} ($@)")
461 if ($self eq $target) {
462 # Pathological case, largely caused by the docs on early C::M::DBIC::Plain
463 foreach my $moniker ($self->sources) {
464 my $source = $self->source($moniker);
465 my $class = $source->result_class;
466 $self->inject_base($class, $base);
467 $class->mk_classdata(resultset_instance => $source->resultset);
468 $class->mk_classdata(class_resolver => $self);
470 $self->connection(@info);
474 my $schema = $self->compose_namespace($target, $base);
477 *{"${target}::schema"} = sub { $schema };
480 $schema->connection(@info);
481 foreach my $moniker ($schema->sources) {
482 my $source = $schema->source($moniker);
483 my $class = $source->result_class;
484 #warn "$moniker $class $source ".$source->storage;
485 $class->mk_classdata(result_source_instance => $source);
486 $class->mk_classdata(resultset_instance => $source->resultset);
487 $class->mk_classdata(class_resolver => $schema);
492 =head2 compose_namespace
496 =item Arguments: $target_namespace, $additional_base_class?
498 =item Return Value: $new_schema
502 For each L<DBIx::Class::ResultSource> in the schema, this method creates a
503 class in the target namespace (e.g. $target_namespace::CD,
504 $target_namespace::Artist) that inherits from the corresponding classes
505 attached to the current schema.
507 It also attaches a corresponding L<DBIx::Class::ResultSource> object to the
508 new $schema object. If C<$additional_base_class> is given, the new composed
509 classes will inherit from first the corresponding classe from the current
510 schema then the base class.
512 For example, for a schema with My::Schema::CD and My::Schema::Artist classes,
514 $schema->compose_namespace('My::DB', 'Base::Class');
515 print join (', ', @My::DB::CD::ISA) . "\n";
516 print join (', ', @My::DB::Artist::ISA) ."\n";
518 will produce the output
520 My::Schema::CD, Base::Class
521 My::Schema::Artist, Base::Class
525 sub compose_namespace {
526 my ($self, $target, $base) = @_;
527 my %reg = %{ $self->source_registrations };
530 my $schema = $self->clone;
532 no warnings qw/redefine/;
533 local *Class::C3::reinitialize = sub { };
534 foreach my $moniker ($schema->sources) {
535 my $source = $schema->source($moniker);
536 my $target_class = "${target}::${moniker}";
538 $target_class => $source->result_class, ($base ? $base : ())
540 $source->result_class($target_class);
541 $target_class->result_source_instance($source)
542 if $target_class->can('result_source_instance');
545 Class::C3->reinitialize();
548 foreach my $meth (qw/class source resultset/) {
549 *{"${target}::${meth}"} =
550 sub { shift->schema->$meth(@_) };
556 =head2 setup_connection_class
560 =item Arguments: $target, @info
564 Sets up a database connection class to inject between the schema and the
565 subclasses that the schema creates.
569 sub setup_connection_class {
570 my ($class, $target, @info) = @_;
571 $class->inject_base($target => 'DBIx::Class::DB');
572 #$target->load_components('DB');
573 $target->connection(@info);
580 =item Arguments: @args
582 =item Return Value: $new_schema
586 Instantiates a new Storage object of type
587 L<DBIx::Class::Schema/"storage_type"> and passes the arguments to
588 $storage->connect_info. Sets the connection in-place on the schema. See
589 L<DBIx::Class::Storage::DBI/"connect_info"> for more information.
594 my ($self, @info) = @_;
595 return $self if !@info && $self->storage;
596 my $storage_class = $self->storage_type;
597 $storage_class = 'DBIx::Class::Storage'.$storage_class
598 if $storage_class =~ m/^::/;
599 eval "require ${storage_class};";
600 $self->throw_exception(
601 "No arguments to load_classes and couldn't load ${storage_class} ($@)"
603 my $storage = $storage_class->new($self);
604 $storage->connect_info(\@info);
605 $self->storage($storage);
613 =item Arguments: @info
615 =item Return Value: $new_schema
619 This is a convenience method. It is equivalent to calling
620 $schema->clone->connection(@info). See L</connection> and L</clone> for more
625 sub connect { shift->clone->connection(@_) }
629 Begins a transaction (does nothing if AutoCommit is off). Equivalent to
630 calling $schema->storage->txn_begin. See
631 L<DBIx::Class::Storage::DBI/"txn_begin"> for more information.
635 sub txn_begin { shift->storage->txn_begin }
639 Commits the current transaction. Equivalent to calling
640 $schema->storage->txn_commit. See L<DBIx::Class::Storage::DBI/"txn_commit">
641 for more information.
645 sub txn_commit { shift->storage->txn_commit }
649 Rolls back the current transaction. Equivalent to calling
650 $schema->storage->txn_rollback. See
651 L<DBIx::Class::Storage::DBI/"txn_rollback"> for more information.
655 sub txn_rollback { shift->storage->txn_rollback }
661 =item Arguments: C<$coderef>, @coderef_args?
663 =item Return Value: The return value of $coderef
667 Executes C<$coderef> with (optional) arguments C<@coderef_args> atomically,
668 returning its result (if any). If an exception is caught, a rollback is issued
669 and the exception is rethrown. If the rollback fails, (i.e. throws an
670 exception) an exception is thrown that includes a "Rollback failed" message.
674 my $author_rs = $schema->resultset('Author')->find(1);
675 my @titles = qw/Night Day It/;
678 # If any one of these fails, the entire transaction fails
679 $author_rs->create_related('books', {
681 }) foreach (@titles);
683 return $author->books;
688 $rs = $schema->txn_do($coderef);
691 if ($@) { # Transaction failed
692 die "something terrible has happened!" #
693 if ($@ =~ /Rollback failed/); # Rollback failed
695 deal_with_failed_transaction();
698 In a nested transaction (calling txn_do() from within a txn_do() coderef) only
699 the outermost transaction will issue a L<DBIx::Class::Schema/"txn_commit"> on
700 the Schema's storage, and txn_do() can be called in void, scalar and list
701 context and it will behave as expected.
706 my ($self, $coderef, @args) = @_;
708 $self->storage or $self->throw_exception
709 ('txn_do called on $schema without storage');
710 ref $coderef eq 'CODE' or $self->throw_exception
711 ('$coderef must be a CODE reference');
713 my (@return_values, $return_value);
715 $self->txn_begin; # If this throws an exception, no rollback is needed
717 my $wantarray = wantarray; # Need to save this since the context
718 # inside the eval{} block is independent
719 # of the context that called txn_do()
722 # Need to differentiate between scalar/list context to allow for
723 # returning a list in scalar context to get the size of the list
726 @return_values = $coderef->(@args);
727 } elsif (defined $wantarray) {
729 $return_value = $coderef->(@args);
745 my $rollback_error = $@;
746 my $exception_class = "DBIx::Class::Storage::NESTED_ROLLBACK_EXCEPTION";
747 $self->throw_exception($error) # propagate nested rollback
748 if $rollback_error =~ /$exception_class/;
750 $self->throw_exception(
751 "Transaction aborted: $error. Rollback failed: ${rollback_error}"
754 $self->throw_exception($error); # txn failed but rollback succeeded
758 return $wantarray ? @return_values : $return_value;
765 =item Return Value: $new_schema
769 Clones the schema and its associated result_source objects and returns the
776 my $clone = bless({ (ref $self ? %$self : ()) }, ref $self || $self);
777 foreach my $moniker ($self->sources) {
778 my $source = $self->source($moniker);
779 my $new = $source->new($source);
780 $clone->register_source($moniker => $new);
782 $clone->storage->set_schema($clone) if $clone->storage;
790 =item Arguments: $moniker, \@data;
794 Populates the source registered with the given moniker with the supplied data.
795 @data should be a list of listrefs -- the first containing column names, the
796 second matching values.
800 $schema->populate('Artist', [
801 [ qw/artistid name/ ],
802 [ 1, 'Popular Band' ],
810 my ($self, $name, $data) = @_;
811 my $rs = $self->resultset($name);
812 my @names = @{shift(@$data)};
814 foreach my $item (@$data) {
816 @create{@names} = @$item;
817 push(@created, $rs->create(\%create));
822 =head2 exception_action
826 =item Arguments: $code_reference
830 If C<exception_action> is set for this class/object, L</throw_exception>
831 will prefer to call this code reference with the exception as an argument,
832 rather than its normal <croak> action.
834 Your subroutine should probably just wrap the error in the exception
835 object/class of your choosing and rethrow. If, against all sage advice,
836 you'd like your C<exception_action> to suppress a particular exception
837 completely, simply have it return true.
842 use base qw/DBIx::Class::Schema/;
843 use My::ExceptionClass;
844 __PACKAGE__->exception_action(sub { My::ExceptionClass->throw(@_) });
845 __PACKAGE__->load_classes;
848 my $schema_obj = My::Schema->connect( .... );
849 $schema_obj->exception_action(sub { My::ExceptionClass->throw(@_) });
851 # suppress all exceptions, like a moron:
852 $schema_obj->exception_action(sub { 1 });
854 =head2 throw_exception
858 =item Arguments: $message
862 Throws an exception. Defaults to using L<Carp::Clan> to report errors from
863 user's perspective. See L</exception_action> for details on overriding
864 this method's behavior.
868 sub throw_exception {
870 croak @_ if !$self->exception_action || !$self->exception_action->(@_);
873 =head2 deploy (EXPERIMENTAL)
877 =item Arguments: $sqlt_args
881 Attempts to deploy the schema to the current storage using L<SQL::Translator>.
883 Note that this feature is currently EXPERIMENTAL and may not work correctly
884 across all databases, or fully handle complex relationships.
886 See L<SQL::Translator/METHODS> for a list of values for C<$sqlt_args>. The most
887 common value for this would be C<< { add_drop_table => 1, } >> to have the SQL
888 produced include a DROP TABLE statement for each table created.
893 my ($self, $sqltargs) = @_;
894 $self->throw_exception("Can't deploy without storage") unless $self->storage;
895 $self->storage->deploy($self, undef, $sqltargs);
898 =head2 create_ddl_dir (EXPERIMENTAL)
902 =item Arguments: \@databases, $version, $directory, $sqlt_args
906 Creates an SQL file based on the Schema, for each of the specified
907 database types, in the given directory.
909 Note that this feature is currently EXPERIMENTAL and may not work correctly
910 across all databases, or fully handle complex relationships.
918 $self->throw_exception("Can't create_ddl_dir without storage") unless $self->storage;
919 $self->storage->create_ddl_dir($self, @_);
922 =head2 ddl_filename (EXPERIMENTAL)
924 my $filename = $table->ddl_filename($type, $dir, $version)
926 Creates a filename for a SQL file based on the table class name. Not
927 intended for direct end user use.
933 my ($self, $type, $dir, $version) = @_;
935 my $filename = ref($self);
936 $filename =~ s/::/-/;
937 $filename = "$dir$filename-$version-$type.sql";
946 Matt S. Trout <mst@shadowcatsystems.co.uk>
950 You may distribute this code under the same terms as Perl itself.