use strict;
use warnings;
-use base qw/Class::Data::Inheritable/;
-use DBIx::Class;
+use Carp::Clan qw/^DBIx::Class/;
-__PACKAGE__->mk_classdata('class_registrations' => {});
+use base qw/DBIx::Class/;
+
+__PACKAGE__->mk_classdata('class_mappings' => {});
+__PACKAGE__->mk_classdata('source_registrations' => {});
+__PACKAGE__->mk_classdata('storage_type' => '::DBI');
+__PACKAGE__->mk_classdata('storage');
=head1 NAME
=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');
- use base qw/DBIx::Class::Core/;
+ # Elsewhere in your code:
+ my $schema1 = My::Schema->connect(
+ $dsn,
+ $user,
+ $password,
+ $attrs
+ );
+
+ my $schema2 = My::Schema->connect($coderef_returning_dbh);
- __PACKAGE__->table('foo');
- ...
+ # fetch objects using My::Schema::Foo
+ my $resultset = $schema1->resultset('Foo')->search( ... );
+ my @objects = $schema2->resultset('Foo')->search( ... );
- in My/DB.pm
+=head1 DESCRIPTION
- use My::Schema;
+Creates database classes based on a schema. This is the recommended way to
+use L<DBIx::Class> and allows you to use more than one concurrent connection
+with your classes.
- My::Schema->compose_connection('My::DB', $dsn, $user, $pass, $attrs);
+NB: If you're used to L<Class::DBI> it's worth reading the L</SYNOPSIS>
+carefully as DBIx::Class does things a little differently. Note in
+particular which module inherits off which.
- then in app code
+=head1 METHODS
- my @obj = My::DB::Foo->retrieve_all; # My::DB::Foo isa My::Schema::Foo My::DB
+=head2 register_class
-=head1 DESCRIPTION
+=head3 Arguments: <moniker> <component_class>
-=head1 METHODS
+Registers a class which isa ResultSourceProxy; equivalent to calling
-=over 4
+ $schema->register_source($moniker, $component_class->result_source_instance);
=cut
sub register_class {
- my ($class, $name, $to_register) = @_;
- my %reg = %{$class->class_registrations};
- $reg{$name} = $to_register;
- $class->class_registrations(\%reg);
+ my ($self, $moniker, $to_register) = @_;
+ $self->register_source($moniker => $to_register->result_source_instance);
+}
+
+=head2 register_source
+
+=head3 Arguments: <moniker> <result source>
+
+Registers the result source in the schema with the given moniker
+
+=cut
+
+sub register_source {
+ my ($self, $moniker, $source) = @_;
+ my %reg = %{$self->source_registrations};
+ $reg{$moniker} = $source;
+ $self->source_registrations(\%reg);
+ $source->schema($self);
+ if ($source->result_class) {
+ my %map = %{$self->class_mappings};
+ $map{$source->result_class} = $moniker;
+ $self->class_mappings(\%map);
+ }
+}
+
+=head2 class
+
+ my $class = $schema->class('Foo');
+
+Retrieves the result class name for a given result source
+
+=cut
+
+sub class {
+ my ($self, $moniker) = @_;
+ return $self->source($moniker)->result_class;
}
-sub registered_classes {
- return values %{shift->class_registrations};
+=head2 source
+
+ my $source = $schema->source('Foo');
+
+Returns the result source object for the registered name
+
+=cut
+
+sub source {
+ my ($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};
}
+=head2 sources
+
+ my @source_monikers = $schema->sources;
+
+Returns the source monikers of all source registrations on this schema
+
+=cut
+
+sub sources { return keys %{shift->source_registrations}; }
+
+=head2 resultset
+
+ my $rs = $schema->resultset('Foo');
+
+Returns the resultset for the registered moniker
+
+=cut
+
+sub resultset {
+ my ($self, $moniker) = @_;
+ return $self->source($moniker)->resultset;
+}
+
+=head2 load_classes
+
+=head3 Arguments: [<classes>, (<class>, <class>), {<namespace> => [<classes>]}]
+
+Uses L<Module::Find> to find all classes under the database class' namespace,
+or uses the classes you select. Then it loads the component (using L<use>),
+and registers them (using B<register_class>);
+
+It is possible to comment out classes with a leading '#', 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 "no warnings 'qw';" before your load_classes call.
+
+=cut
+
sub load_classes {
- my $class = shift;
- my @comp = grep { $_ !~ /^#/ } @_;
- foreach my $comp (@comp) {
- my $comp_class = "${class}::${comp}";
- eval "use $comp_class";
- die $@ if $@;
- $class->register_class($comp => $comp_class);
+ my ($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;";
+ $class->throw_exception("No arguments to load_classes and couldn't load".
+ " Module::Find ($@)") if $@;
+ my @comp = map { substr $_, length "${class}::" } Module::Find::findallmod($class);
+ $comps_for{$class} = \@comp;
+ }
+
+ 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 $class->can('result_source_instance');
}
}
+=head2 compose_connection
+
+=head3 Arguments: <target> <@db_info>
+
+This is the most important method in this class. it takes a target namespace,
+as well as dbh connection info, and creates a L<DBIx::Class::DB> class as
+well as subclasses for each of your database classes in this namespace, using
+this connection.
+
+It will also setup a ->class method on the target class, which lets you
+resolve database classes based on the schema component name, for example
+
+ MyApp::DB->class('Foo') # returns MyApp::DB::Foo,
+ # which ISA MyApp::Schema::Foo
+
+This is the recommended API for accessing Schema generated classes, and
+using it might give you instant advantages with future versions of DBIC.
+
+WARNING: Loading components into Schema classes after compose_connection
+may not cause them to be seen by the classes in your target namespace due
+to the dispatch table approach used by Class::C3. If you do this you may find
+you need to call Class::C3->reinitialize() afterwards to get the behaviour
+you expect.
+
+=cut
+
sub compose_connection {
- my ($class, $target, @info) = @_;
- $class->setup_connection_class($target, @info);
- my %reg = %{ $class->class_registrations };
- while (my ($comp, $comp_class) = each %reg) {
- my $target_class = "${target}::${comp}";
- $class->inject_base($target_class, $comp_class, $target);
+ my ($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 $schema;
}
+sub compose_namespace {
+ my ($self, $target, $base) = @_;
+ my %reg = %{ $self->source_registrations };
+ my %target;
+ my %map;
+ 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';
+ foreach my $meth (qw/class source resultset/) {
+ *{"${target}::${meth}"} =
+ sub { shift->schema->$meth(@_) };
+ }
+ }
+ return $schema;
+}
+
+=head2 setup_connection_class
+
+=head3 Arguments: <$target> <@info>
+
+Sets up a database connection class to inject between the schema
+and the subclasses the schema creates.
+
+=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');
$target->connection(@info);
}
-sub inject_base {
- my ($class, $target, @to_inject) = @_;
- {
- no strict 'refs';
- unshift(@{"${target}::ISA"}, @to_inject);
+=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 $clone;
}
-1;
+=head2 populate
+
+=head3 Arguments: ($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.
-=back
+ $schema->populate('Foo', [
+ [ qw/foo_id foo_string/ ],
+ [ 1, 'One' ],
+ [ 2, 'Two' ],
+ ...
+ ]);
+
+=cut
+
+sub populate {
+ my ($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
-Matt S. Trout <perl-stuff@trout.me.uk>
+Matt S. Trout <mst@shadowcatsystems.co.uk>
=head1 LICENSE