X-Git-Url: http://git.shadowcat.co.uk/gitweb/gitweb.cgi?a=blobdiff_plain;f=lib%2FDBIx%2FClass%2FSchema.pm;h=9105477748396ca9834616b80d6322b6e59f5492;hb=a917fb06c55daf3283effbd3857f41e7e077c695;hp=88dfd5b3941b408fc11d4799e0ac0be93654f74d;hpb=42a1aaa1b07291dfcfb83348d9ce8f6a542c8726;p=dbsrgits%2FDBIx-Class.git diff --git a/lib/DBIx/Class/Schema.pm b/lib/DBIx/Class/Schema.pm index 88dfd5b..9105477 100644 --- a/lib/DBIx/Class/Schema.pm +++ b/lib/DBIx/Class/Schema.pm @@ -3,11 +3,15 @@ package DBIx::Class::Schema; use strict; use warnings; -use base qw/Class::Data::Inheritable/; +use Carp::Clan qw/^DBIx::Class/; +use Scalar::Util qw/weaken/; + use base qw/DBIx::Class/; -__PACKAGE__->load_components(qw/Exception/); -__PACKAGE__->mk_classdata('class_registrations' => {}); +__PACKAGE__->mk_classdata('class_mappings' => {}); +__PACKAGE__->mk_classdata('source_registrations' => {}); +__PACKAGE__->mk_classdata('storage_type' => '::DBI'); +__PACKAGE__->mk_classdata('storage'); =head1 NAME @@ -15,162 +19,702 @@ DBIx::Class::Schema - composable schemas =head1 SYNOPSIS -in My/Schema.pm + package Library::Schema; + use base qw/DBIx::Class::Schema/; + + # load Library::Schema::CD, Library::Schema::Book, Library::Schema::DVD + __PACKAGE__->load_classes(qw/CD Book DVD/); - package My::Schema; + package Library::Schema::CD; + use base qw/DBIx::Class/; + __PACKAGE__->load_components(qw/PK::Auto Core/); # for example + __PACKAGE__->table('cd'); + + # Elsewhere in your code: + my $schema1 = Library::Schema->connect( + $dsn, + $user, + $password, + { AutoCommit => 0 }, + ); + + my $schema2 = Library::Schema->connect($coderef_returning_dbh); + + # fetch objects using Library::Schema::DVD + my $resultset = $schema1->resultset('DVD')->search( ... ); + my @dvd_objects = $schema2->resultset('DVD')->search( ... ); - use base qw/DBIx::Class::Schema/; +=head1 DESCRIPTION - __PACKAGE__->load_classes(qw/Foo Bar Baz/); +Creates database classes based on a schema. This is the recommended way to +use L and allows you to use more than one concurrent connection +with your classes. -in My/Schema/Foo.pm +NB: If you're used to L it's worth reading the L +carefully, as DBIx::Class does things a little differently. Note in +particular which module inherits off which. - package My::Schema::Foo; +=head1 METHODS - use base qw/DBIx::Class/; +=head2 register_class - __PACKAGE__->load_components(qw/Core PK::Auto::Pg/); # for example - __PACKAGE__->table('foo'); - ... +=over 4 -in My/DB.pm +=item Arguments: $moniker, $component_class - use My::Schema; +=back - My::Schema->compose_connection('My::DB', $dsn, $user, $pass, $attrs); +Registers a class which isa DBIx::Class::ResultSourceProxy. Equivalent to +calling: -then in app code + $schema->register_source($moniker, $component_class->result_source_instance); - my @obj = My::DB::Foo->search({}); # My::DB::Foo isa My::Schema::Foo My::DB +=cut -=head1 DESCRIPTION +sub register_class { + my ($self, $moniker, $to_register) = @_; + $self->register_source($moniker => $to_register->result_source_instance); +} -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 directly instead. +=head2 register_source -NB: If you're used to L it's worth reading the L -carefully as DBIx::Class does things a little differently. Note in -particular which module inherits off which. +=over 4 -=head1 METHODS +=item Arguments: $moniker, $result_source + +=back + +Registers the L in the schema with the given +moniker. + +=cut + +sub register_source { + my ($self, $moniker, $source) = @_; + my %reg = %{$self->source_registrations}; + $reg{$moniker} = $source; + $self->source_registrations(\%reg); + $source->schema($self); + weaken($source->{schema}) if ref($self); + if ($source->result_class) { + my %map = %{$self->class_mappings}; + $map{$source->result_class} = $moniker; + $self->class_mappings(\%map); + } +} + +=head2 class =over 4 -=item register_class +=item Arguments: $moniker -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. +=item Return Value: $classname + +=back + +Retrieves the result class name for the given moniker. For example: + + my $class = $schema->class('CD'); =cut -sub register_class { - my ($class, $name, $to_register) = @_; - my %reg = %{$class->class_registrations}; - $reg{$name} = $to_register; - $class->class_registrations(\%reg); +sub class { + my ($self, $moniker) = @_; + return $self->source($moniker)->result_class; } -=item registered_classes +=head2 source + +=over 4 + +=item Arguments: $moniker + +=item Return Value: $result_source + +=back -Simple read-only accessor for the schema's registered classes. See -register_class above if you want to modify it. + my $source = $schema->source('Book'); +Returns the L object for the registered moniker. =cut -sub registered_classes { - return values %{shift->class_registrations}; +sub source { + my ($self, $moniker) = @_; + my $sreg = $self->source_registrations; + return $sreg->{$moniker} if exists $sreg->{$moniker}; + + # if we got here, they probably passed a full class name + my $mapped = $self->class_mappings->{$moniker}; + $self->throw_exception("Can't find source for ${moniker}") + unless $mapped && exists $sreg->{$mapped}; + return $sreg->{$mapped}; } -=item load_classes [} +=head2 sources + +=over 4 + +=item Return Value: @source_monikers + +=back + +Returns the source monikers of all source registrations on this schema. +For example: -Uses L to find all classes under the database class' namespace, -or uses the classes you select. Then it loads the component (using L), -and registers them (using B); + my @source_monikers = $schema->sources; + +=cut + +sub sources { return keys %{shift->source_registrations}; } + +=head2 resultset + +=over 4 + +=item Arguments: $moniker + +=item Return Value: $result_set + +=back + + my $rs = $schema->resultset('DVD'); + +Returns the L object for the registered moniker. + +=cut + +sub resultset { + my ($self, $moniker) = @_; + return $self->source($moniker)->resultset; +} + +=head2 load_classes + +=over 4 + +=item Arguments: @classes?, { $namespace => [ @classes ] }+ + +=back + +With no arguments, this method uses L to find all classes under +the schema's namespace. Otherwise, this method loads the classes you specify +(using L), and registers them (using L). + +It is possible to comment out classes with a leading C<#>, 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 C before your load_classes call. + +Example: + + My::Schema->load_classes(); # loads My::Schema::CD, My::Schema::Artist, + # etc. (anything under the My::Schema namespace) + + # loads My::Schema::CD, My::Schema::Artist, Other::Namespace::Producer but + # not Other::Namespace::LinerNotes nor My::Schema::Track + My::Schema->load_classes(qw/ CD Artist #Track /, { + Other::Namespace => [qw/ Producer #LinerNotes /], + }); =cut sub load_classes { - my $class = shift; - my @comp = grep { $_ !~ /^#/ } @_; - unless (@comp) { + my ($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 $@; - @comp = map { substr $_, length "${class}::" } - Module::Find::findallmod($class); + $class->throw_exception( + "No arguments to load_classes and couldn't load Module::Find ($@)" + ) if $@; + my @comp = map { substr $_, length "${class}::" } + Module::Find::findallmod($class); + $comps_for{$class} = \@comp; } - foreach my $comp (@comp) { - my $comp_class = "${class}::${comp}"; - eval "use $comp_class"; # If it fails, assume the user fixed it - $class->register_class($comp => $comp_class); + + my @to_register; + { + no warnings qw/redefine/; + local *Class::C3::reinitialize = sub { }; + foreach my $prefix (keys %comps_for) { + foreach my $comp (@{$comps_for{$prefix}||[]}) { + my $comp_class = "${prefix}::${comp}"; + eval "use $comp_class"; # If it fails, assume the user fixed it + if ($@) { + $comp_class =~ s/::/\//g; + die $@ unless $@ =~ /Can't locate.+$comp_class\.pm\sin\s\@INC/; + warn $@ if $@; + } + push(@to_register, [ $comp, $comp_class ]); + } + } + } + Class::C3->reinitialize; + + foreach my $to (@to_register) { + $class->register_class(@$to); + # if $class->can('result_source_instance'); } } -=item compose_connection <@db_info> +=head2 compose_connection -This is the most important method in this class. it takes a target namespace, -as well as dbh connection info, and creates a L class as -well as subclasses for each of your database classes in this namespace, using -this connection. +=over 4 + +=item Arguments: $target_namespace, @db_info -It will also setup a ->table method on the target class, which lets you -resolve database classes based on the schema component name, for example +=item Return Value: $new_schema + +=back - MyApp::DB->table('Foo') # returns MyApp::DB::Foo, - # which ISA MyApp::Schema::Foo +Calls L to the target namespace, +calls L with @db_info on the new schema, +then injects the L component and a +resultset_instance classdata entry on all the new classes, in order to support +$target_namespaces::$class->search(...) method calls. -This is the recommended API for accessing Schema generated classes, and -using it might give you instant advantages with future versions of DBIC. +This is primarily useful when you have a specific need for class method access +to a connection. In normal usage it is preferred to call +L and use the resulting schema object to operate +on L objects with L for +more information. =cut sub compose_connection { - my ($class, $target, @info) = @_; - my $conn_class = "${target}::_db"; - $class->setup_connection_class($conn_class, @info); - my %reg = %{ $class->class_registrations }; + my ($self, $target, @info) = @_; + my $base = 'DBIx::Class::ResultSetProxy'; + eval "require ${base};"; + $self->throw_exception + ("No arguments to load_classes and couldn't load ${base} ($@)") + if $@; + + if ($self eq $target) { + # Pathological case, largely caused by the docs on early C::M::DBIC::Plain + foreach my $moniker ($self->sources) { + my $source = $self->source($moniker); + my $class = $source->result_class; + $self->inject_base($class, $base); + $class->mk_classdata(resultset_instance => $source->resultset); + $class->mk_classdata(class_resolver => $self); + } + $self->connection(@info); + return $self; + } + + my $schema = $self->compose_namespace($target, $base); + { + no strict 'refs'; + *{"${target}::schema"} = sub { $schema }; + } + + $schema->connection(@info); + foreach my $moniker ($schema->sources) { + my $source = $schema->source($moniker); + my $class = $source->result_class; + #warn "$moniker $class $source ".$source->storage; + $class->mk_classdata(result_source_instance => $source); + $class->mk_classdata(resultset_instance => $source->resultset); + $class->mk_classdata(class_resolver => $schema); + } + return $schema; +} + +=head2 compose_namespace + +=over 4 + +=item Arguments: $target_namespace, $additional_base_class? + +=item Return Value: $new_schema + +=back + +For each L in the schema, this method creates a +class in the target namespace (e.g. $target_namespace::CD, +$target_namespace::Artist) that inherits from the corresponding classes +attached to the current schema. + +It also attaches a corresponding L object to the +new $schema object. If C<$additional_base_class> is given, the new composed +classes will inherit from first the corresponding classe from the current +schema then the base class. + +For example, for a schema with My::Schema::CD and My::Schema::Artist classes, + + $schema->compose_namespace('My::DB', 'Base::Class'); + print join (', ', @My::DB::CD::ISA) . "\n"; + print join (', ', @My::DB::Artist::ISA) ."\n"; + +will produce the output + + My::Schema::CD, Base::Class + My::Schema::Artist, Base::Class + +=cut + +sub compose_namespace { + my ($self, $target, $base) = @_; + my %reg = %{ $self->source_registrations }; my %target; my %map; - while (my ($comp, $comp_class) = each %reg) { - my $target_class = "${target}::${comp}"; - $class->inject_base($target_class, $conn_class, $comp_class); - $target_class->table($comp_class->table); - @map{$comp, $comp_class} = ($target_class, $target_class); + my $schema = $self->clone; + { + no warnings qw/redefine/; + local *Class::C3::reinitialize = sub { }; + foreach my $moniker ($schema->sources) { + my $source = $schema->source($moniker); + my $target_class = "${target}::${moniker}"; + $self->inject_base( + $target_class => $source->result_class, ($base ? $base : ()) + ); + $source->result_class($target_class); + } } + Class::C3->reinitialize(); { no strict 'refs'; - *{"${target}::class"} = - sub { - my ($class, $to_map) = @_; - return $map{$to_map}; - }; - *{"${target}::classes"} = sub { return \%map; }; + foreach my $meth (qw/class source resultset/) { + *{"${target}::${meth}"} = + sub { shift->schema->$meth(@_) }; + } } - $conn_class->class_resolver($target); + return $schema; } -=item setup_connection_class <$target> <@info> +=head2 setup_connection_class + +=over 4 + +=item Arguments: $target, @info + +=back -Sets up a database connection class to inject between the schema -and the subclasses the schema creates. +Sets up a database connection class to inject between the schema and the +subclasses that the schema creates. =cut sub setup_connection_class { my ($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); } -1; +=head2 connection + +=over 4 + +=item Arguments: @args + +=item Return Value: $new_schema + +=back + +Instantiates a new Storage object of type +L and passes the arguments to +$storage->connect_info. Sets the connection in-place on the schema. See +L for more information. + +=cut + +sub connection { + my ($self, @info) = @_; + return $self if !@info && $self->storage; + my $storage_class = $self->storage_type; + $storage_class = 'DBIx::Class::Storage'.$storage_class + if $storage_class =~ m/^::/; + eval "require ${storage_class};"; + $self->throw_exception( + "No arguments to load_classes and couldn't load ${storage_class} ($@)" + ) if $@; + my $storage = $storage_class->new; + $storage->connect_info(\@info); + $self->storage($storage); + return $self; +} + +=head2 connect + +=over 4 + +=item Arguments: @info + +=item Return Value: $new_schema + +=back + +This is a convenience method. It is equivalent to calling +$schema->clone->connection(@info). See L and L for more +information. + +=cut + +sub connect { shift->clone->connection(@_) } + +=head2 txn_begin + +Begins a transaction (does nothing if AutoCommit is off). Equivalent to +calling $schema->storage->txn_begin. See +L for more information. + +=cut + +sub txn_begin { shift->storage->txn_begin } + +=head2 txn_commit + +Commits the current transaction. Equivalent to calling +$schema->storage->txn_commit. See L +for more information. + +=cut + +sub txn_commit { shift->storage->txn_commit } + +=head2 txn_rollback + +Rolls back the current transaction. Equivalent to calling +$schema->storage->txn_rollback. See +L for more information. + +=cut + +sub txn_rollback { shift->storage->txn_rollback } + +=head2 txn_do + +=over 4 + +=item Arguments: C<$coderef>, @coderef_args? + +=item Return Value: The return value of $coderef =back +Executes C<$coderef> with (optional) arguments C<@coderef_args> atomically, +returning its result (if any). If an exception is caught, a rollback is issued +and the exception is rethrown. If the rollback fails, (i.e. throws an +exception) an exception is thrown that includes a "Rollback failed" message. + +For example, + + my $author_rs = $schema->resultset('Author')->find(1); + + my $coderef = sub { + my ($author, @titles) = @_; + + # If any one of these fails, the entire transaction fails + $author->create_related('books', { + title => $_ + }) foreach (@titles); + + return $author->books; + }; + + my $rs; + eval { + $rs = $schema->txn_do($coderef, $author_rs, qw/Night Day It/); + }; + + if ($@) { + my $error = $@; + if ($error =~ /Rollback failed/) { + die "something terrible has happened!"; + } else { + deal_with_failed_transaction(); + } + } + +In a nested transaction (calling txn_do() from within a txn_do() coderef) only +the outermost transaction will issue a L on +the Schema's storage, and txn_do() can be called in void, scalar and list +context and it will behave as expected. + +=cut + +sub txn_do { + my ($self, $coderef, @args) = @_; + + ref $self or $self->throw_exception + ('Cannot execute txn_do as a class method'); + ref $coderef eq 'CODE' or $self->throw_exception + ('$coderef must be a CODE reference'); + + my (@return_values, $return_value); + + $self->txn_begin; # If this throws an exception, no rollback is needed + + my $wantarray = wantarray; # Need to save this since the context + # inside the eval{} block is independent + # of the context that called txn_do() + eval { + + # Need to differentiate between scalar/list context to allow for + # returning a list in scalar context to get the size of the list + if ($wantarray) { + # list context + @return_values = $coderef->(@args); + } elsif (defined $wantarray) { + # scalar context + $return_value = $coderef->(@args); + } else { + # void context + $coderef->(@args); + } + $self->txn_commit; + }; + + if ($@) { + my $error = $@; + + eval { + $self->txn_rollback; + }; + + if ($@) { + my $rollback_error = $@; + my $exception_class = "DBIx::Class::Storage::NESTED_ROLLBACK_EXCEPTION"; + $self->throw_exception($error) # propagate nested rollback + if $rollback_error =~ /$exception_class/; + + $self->throw_exception( + "Transaction aborted: $error. Rollback failed: ${rollback_error}" + ); + } else { + $self->throw_exception($error); # txn failed but rollback succeeded + } + } + + return $wantarray ? @return_values : $return_value; +} + +=head2 clone + +=over 4 + +=item Return Value: $new_schema + +=back + +Clones the schema and its associated result_source objects and returns the +copy. + +=cut + +sub clone { + my ($self) = @_; + my $clone = bless({ (ref $self ? %$self : ()) }, ref $self || $self); + foreach my $moniker ($self->sources) { + my $source = $self->source($moniker); + my $new = $source->new($source); + $clone->register_source($moniker => $new); + } + return $clone; +} + +=head2 populate + +=over 4 + +=item Arguments: $moniker, \@data; + +=back + +Populates the source registered with the given moniker with the supplied data. +@data should be a list of listrefs -- the first containing column names, the +second matching values. + +i.e., + + $schema->populate('Artist', [ + [ qw/artistid name/ ], + [ 1, 'Popular Band' ], + [ 2, 'Indie Band' ], + ... + ]); + +=cut + +sub populate { + my ($self, $name, $data) = @_; + my $rs = $self->resultset($name); + my @names = @{shift(@$data)}; + my @created; + foreach my $item (@$data) { + my %create; + @create{@names} = @$item; + push(@created, $rs->create(\%create)); + } + return @created; +} + +=head2 throw_exception + +=over 4 + +=item Arguments: $message + +=back + +Throws an exception. Defaults to using L to report errors from +user's perspective. + +=cut + +sub throw_exception { + my ($self) = shift; + croak @_; +} + +=head2 deploy (EXPERIMENTAL) + +=over 4 + +=item Arguments: $sqlt_args + +=back + +Attempts to deploy the schema to the current storage using L. + +Note that this feature is currently EXPERIMENTAL and may not work correctly +across all databases, or fully handle complex relationships. + +=cut + +sub deploy { + my ($self, $sqltargs) = @_; + $self->throw_exception("Can't deploy without storage") unless $self->storage; + $self->storage->deploy($self, undef, $sqltargs); +} + +1; + =head1 AUTHORS Matt S. Trout