X-Git-Url: http://git.shadowcat.co.uk/gitweb/gitweb.cgi?a=blobdiff_plain;f=lib%2FDBIx%2FClass%2FSchema.pm;h=21ae98015140e8fbe34649378bd0cfbd70eaf054;hb=3b24f6ea87d4339179f2752b661d85dd08827d8f;hp=8c3d2884e0ccb84c76821cefebc0375d44d77898;hpb=0dc792491a0296584ea02abe0071ab7bd7d4618a;p=dbsrgits%2FDBIx-Class.git diff --git a/lib/DBIx/Class/Schema.pm b/lib/DBIx/Class/Schema.pm index 8c3d288..21ae980 100644 --- a/lib/DBIx/Class/Schema.pm +++ b/lib/DBIx/Class/Schema.pm @@ -2,14 +2,14 @@ package DBIx::Class::Schema; use strict; use warnings; -use DBIx::Class::DB; + +use Carp::Clan qw/^DBIx::Class/; use base qw/DBIx::Class/; -__PACKAGE__->load_components(qw/Exception/); __PACKAGE__->mk_classdata('class_mappings' => {}); __PACKAGE__->mk_classdata('source_registrations' => {}); -__PACKAGE__->mk_classdata('storage_type' => 'DBI'); +__PACKAGE__->mk_classdata('storage_type' => '::DBI'); __PACKAGE__->mk_classdata('storage'); =head1 NAME @@ -18,40 +18,36 @@ DBIx::Class::Schema - composable schemas =head1 SYNOPSIS -in My/Schema.pm - package My::Schema; - use base qw/DBIx::Class::Schema/; - + + # load My::Schema::Foo, My::Schema::Bar, My::Schema::Baz __PACKAGE__->load_classes(qw/Foo Bar Baz/); -in My/Schema/Foo.pm - package My::Schema::Foo; - use base qw/DBIx::Class/; - __PACKAGE__->load_components(qw/PK::Auto::Pg Core/); # for example __PACKAGE__->table('foo'); - ... -in My/DB.pm - - use My::Schema; - - My::Schema->compose_connection('My::DB', $dsn, $user, $pass, $attrs); - -then in app code + # Elsewhere in your code: + my $schema1 = My::Schema->connect( + $dsn, + $user, + $password, + $attrs + ); + + my $schema2 = My::Schema->connect($coderef_returning_dbh); - my @obj = My::DB::Foo->search({}); # My::DB::Foo isa My::Schema::Foo My::DB + # fetch objects using My::Schema::Foo + my $resultset = $schema1->resultset('Foo')->search( ... ); + my @objects = $schema2->resultset('Foo')->search( ... ); =head1 DESCRIPTION -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. +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. NB: If you're used to L it's worth reading the L carefully as DBIx::Class does things a little differently. Note in @@ -59,11 +55,13 @@ particular which module inherits off which. =head1 METHODS -=head2 register_class +=head2 register_class -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. +=head3 Arguments: + +Registers a class which isa ResultSourceProxy; equivalent to calling + + $schema->register_source($moniker, $component_class->result_source_instance); =cut @@ -72,7 +70,9 @@ sub register_class { $self->register_source($moniker => $to_register->result_source_instance); } -=head2 register_source +=head2 register_source + +=head3 Arguments: Registers the result source in the schema with the given moniker @@ -119,7 +119,7 @@ sub source { # if we got here, they probably passed a full class name my $mapped = $self->class_mappings->{$moniker}; - die "Can't find source for ${moniker}" + $self->throw_exception("Can't find source for ${moniker}") unless $mapped && exists $sreg->{$mapped}; return $sreg->{$mapped}; } @@ -147,7 +147,9 @@ sub resultset { return $self->source($moniker)->resultset; } -=head2 load_classes [, (, ), { => []}] +=head2 load_classes + +=head3 Arguments: [, (, ), { => []}] Uses L to find all classes under the database class' namespace, or uses the classes you select. Then it loads the component (using L), @@ -188,25 +190,40 @@ sub load_classes { } } else { eval "require Module::Find;"; - $class->throw("No arguments to load_classes and couldn't load". + $class->throw_exception("No arguments to load_classes and couldn't load". " Module::Find ($@)") if $@; my @comp = map { substr $_, length "${class}::" } Module::Find::findallmod($class); $comps_for{$class} = \@comp; } - foreach my $prefix (keys %comps_for) { - foreach my $comp (@{$comps_for{$prefix}||[]}) { - my $comp_class = "${prefix}::${comp}"; - eval "use $comp_class"; # If it fails, assume the user fixed it - if ($@) { - die $@ unless $@ =~ /Can't locate/; + 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 ]); } - $class->register_class($comp => $comp_class); } } + Class::C3->reinitialize; + + foreach my $to (@to_register) { + $class->register_class(@$to); + # if $class->can('result_source_instance'); + } } -=head2 compose_connection <@db_info> +=head2 compose_connection + +=head3 Arguments: <@db_info> This is the most important method in this class. it takes a target namespace, as well as dbh connection info, and creates a L class as @@ -232,51 +249,74 @@ you expect. sub compose_connection { my ($self, $target, @info) = @_; - my $conn_class = "${target}::_db"; - $self->setup_connection_class($conn_class, @info); - my $schema = $self->compose_namespace($target, $conn_class); - $schema->storage($conn_class->storage); + 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 $schema; } sub compose_namespace { - my ($class, $target, $base) = @_; - my %reg = %{ $class->source_registrations }; + my ($self, $target, $base) = @_; + my %reg = %{ $self->source_registrations }; my %target; my %map; - my $schema = bless({ }, $class); - while (my ($moniker, $source) = each %reg) { - my $target_class = "${target}::${moniker}"; - $class->inject_base( - $target_class => $source->result_class, ($base ? $base : ()) - ); - my $new_source = $source->new($source); - $new_source->result_class($target_class); - $new_source->schema($schema); - $map{$moniker} = $new_source; + 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); + } } - $schema->source_registrations(\%map); + Class::C3->reinitialize(); { no strict 'refs'; - *{"${target}::schema"} = - sub { $schema }; foreach my $meth (qw/class source resultset/) { *{"${target}::${meth}"} = sub { shift->schema->$meth(@_) }; } } - $base->class_resolver($target); return $schema; } -=head2 setup_connection_class <$target> <@info> +=head2 setup_connection_class + +=head3 Arguments: <$target> <@info> Sets up a database connection class to inject between the schema and the subclasses the schema creates. @@ -290,6 +330,229 @@ sub setup_connection_class { $target->connection(@info); } +=head2 connection + +=head3 Arguments: (@args) + +Instantiates a new Storage object of type storage_type and passes the +arguments to $storage->connect_info. Sets the connection in-place on +the schema. + +=cut + +sub connection { + my ($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 + +=head3 Arguments: (@info) + +Conveneience method, equivalent to $schema->clone->connection(@info) + +=cut + +sub connect { shift->clone->connection(@_) } + +=head2 txn_begin + +Begins a transaction (does nothing if AutoCommit is off). + +=cut + +sub txn_begin { shift->storage->txn_begin } + +=head2 txn_commit + +Commits the current transaction. + +=cut + +sub txn_commit { shift->storage->txn_commit } + +=head2 txn_rollback + +Rolls back the current transaction. + +=cut + +sub txn_rollback { shift->storage->txn_rollback } + +=head2 txn_do + +=head3 Arguments: <$coderef>, [@coderef_args] + +Executes C<$coderef> with (optional) arguments C<@coderef_args> +transactionally, 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 $foo = $schema->resultset('foo')->find(1); + + my $coderef = sub { + my ($foo, @bars) = @_; + + # If any one of these fails, the entire transaction fails + $foo->create_related('bars', { + col => $_ + }) foreach (@bars); + + return $foo->bars; + }; + + my $rs; + eval { + $rs = $schema->txn_do($coderef, $foo, qw/foo bar baz/); + }; + + if ($@) { + my $error = $@; + if ($error =~ /Rollback failed/) { + die "something terrible has happened!"; + } else { + deal_with_failed_transaction(); + die $error; + } + } + +Nested transactions work as expected (i.e. only the outermost +transaction will issue a txn_commit on the Schema's storage) + +=cut + +sub txn_do { + my ($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 $wantarray = wantarray; # Need to save this since it's reset in eval{} + + eval { + # Need to differentiate between scalar/list context to allow for returning + # a list in scalar context to get the size of the list + if ($wantarray) { + @return_values = $coderef->(@args); + } else { + $return_value = $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 : $return_value; +} + +=head2 clone + +Clones the schema and its associated result_source objects and returns the +copy. + +=cut + +sub clone { + my ($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 $clone; +} + +=head2 populate + +=head3 Arguments: ($moniker, \@data); + +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. + + $schema->populate('Foo', [ + [ qw/foo_id foo_string/ ], + [ 1, 'One' ], + [ 2, 'Two' ], + ... + ]); + +=cut + +sub populate { + my ($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, $rs->create(\%create)); + } + return @created; +} + +=head2 throw_exception + +Defaults to using Carp::Clan to report errors from user perspective. + +=cut + +sub throw_exception { + my ($self) = shift; + croak @_; +} + +=head2 deploy + +Attempts to deploy the schema to the current storage + +=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