use warnings;
use Carp::Clan qw/^DBIx::Class/;
+use Scalar::Util qw/weaken/;
use base qw/DBIx::Class/;
=head1 SYNOPSIS
- package My::Schema;
+ package Library::Schema;
use base qw/DBIx::Class::Schema/;
-
- # load My::Schema::Foo, My::Schema::Bar, My::Schema::Baz
- __PACKAGE__->load_classes(qw/Foo Bar Baz/);
- package My::Schema::Foo;
+ # load Library::Schema::CD, Library::Schema::Book, Library::Schema::DVD
+ __PACKAGE__->load_classes(qw/CD Book DVD/);
+
+ package Library::Schema::CD;
use base qw/DBIx::Class/;
- __PACKAGE__->load_components(qw/PK::Auto::Pg Core/); # for example
- __PACKAGE__->table('foo');
+ __PACKAGE__->load_components(qw/PK::Auto Core/); # for example
+ __PACKAGE__->table('cd');
# Elsewhere in your code:
- my $schema1 = My::Schema->connect(
+ my $schema1 = Library::Schema->connect(
$dsn,
$user,
$password,
- $attrs
+ { AutoCommit => 0 },
);
-
- my $schema2 = My::Schema->connect($coderef_returning_dbh);
- # fetch objects using My::Schema::Foo
- my $resultset = $schema1->resultset('Foo')->search( ... );
- my @objects = $schema2->resultset('Foo')->search( ... );
+ 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( ... );
=head1 DESCRIPTION
with your classes.
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
+carefully, as DBIx::Class does things a little differently. Note in
particular which module inherits off which.
=head1 METHODS
=head2 register_class
-=head3 Arguments: <moniker> <component_class>
+=over 4
+
+=item Arguments: $moniker, $component_class
+
+=back
-Registers a class which isa ResultSourceProxy; equivalent to calling
+Registers a class which isa DBIx::Class::ResultSourceProxy. Equivalent to
+calling:
$schema->register_source($moniker, $component_class->result_source_instance);
=head2 register_source
-=head3 Arguments: <moniker> <result source>
+=over 4
-Registers the result source in the schema with the given moniker
+=item Arguments: $moniker, $result_source
+
+=back
+
+Registers the L<DBIx::Class::ResultSource> in the schema with the given
+moniker.
=cut
$reg{$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
- my $class = $schema->class('Foo');
+=over 4
-Retrieves the result class name for a given result source
+=item Arguments: $moniker
+
+=item Return Value: $classname
+
+=back
+
+Retrieves the result class name for the given moniker. For example:
+
+ my $class = $schema->class('CD');
=cut
=head2 source
- my $source = $schema->source('Foo');
+=over 4
+
+=item Arguments: $moniker
+
+=item Return Value: $result_source
-Returns the result source object for the registered name
+=back
+
+ my $source = $schema->source('Book');
+
+Returns the L<DBIx::Class::ResultSource> object for the registered moniker.
=cut
=head2 sources
- my @source_monikers = $schema->sources;
+=over 4
+
+=item Return Value: @source_monikers
-Returns the source monikers of all source registrations on this schema
+=back
+
+Returns the source monikers of all source registrations on this schema.
+For example:
+
+ my @source_monikers = $schema->sources;
=cut
=head2 resultset
- my $rs = $schema->resultset('Foo');
+=over 4
-Returns the resultset for the registered moniker
+=item Arguments: $moniker
+
+=item Return Value: $result_set
+
+=back
+
+ my $rs = $schema->resultset('DVD');
+
+Returns the L<DBIx::Class::ResultSet> object for the registered moniker.
=cut
=head2 load_classes
-=head3 Arguments: [<classes>, (<class>, <class>), {<namespace> => [<classes>]}]
+=over 4
+
+=item Arguments: @classes?, { $namespace => [ @classes ] }+
+
+=back
-Uses L<Module::Find> to find all classes under the database class' namespace,
-or uses the classes you select. Then it loads the component (using L<use>),
-and registers them (using B<register_class>);
+With no arguments, this method uses L<Module::Find> to find all classes under
+the schema's namespace. Otherwise, this method loads the classes you specify
+(using L<use>), and registers them (using L</"register_class">).
-It is possible to comment out classes with a leading '#', but note that perl
-will think it's a mistake (trying to use a comment in a qw list) so you'll
-need to add "no warnings 'qw';" before your load_classes call.
+It is possible to comment out classes with a leading C<#>, but note that perl
+will think it's a mistake (trying to use a comment in a qw list), so you'll
+need to add C<no warnings 'qw';> before your load_classes call.
+
+Example:
+
+ My::Schema->load_classes(); # loads My::Schema::CD, My::Schema::Artist,
+ # etc. (anything under the My::Schema namespace)
+
+ # loads My::Schema::CD, My::Schema::Artist, Other::Namespace::Producer but
+ # not Other::Namespace::LinerNotes nor My::Schema::Track
+ My::Schema->load_classes(qw/ CD Artist #Track /, {
+ Other::Namespace => [qw/ Producer #LinerNotes /],
+ });
=cut
sub load_classes {
my ($class, @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') {
}
} 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);
+ $class->throw_exception(
+ "No arguments to load_classes and couldn't load Module::Find ($@)"
+ ) 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 $comp_class"; # If it fails, assume the user fixed it
- if ($@) {
- $comp_class =~ s/::/\//g;
- die $@ unless $@ =~ /Can't locate.+$comp_class\.pm\sin\s\@INC/;
- warn $@ if $@;
- }
- push(@to_register, [ $comp, $comp_class ]);
+ $class->ensure_class_loaded($comp_class);
+ $comp_class->source_name($comp) unless $comp_class->source_name;
+
+ push(@to_register, [ $comp_class->source_name, $comp_class ]);
}
}
}
=head2 compose_connection
-=head3 Arguments: <target> <@db_info>
+=over 4
-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.
+=item Arguments: $target_namespace, @db_info
-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
+=item Return Value: $new_schema
- MyApp::DB->class('Foo') # returns MyApp::DB::Foo,
- # which ISA MyApp::Schema::Foo
+=back
-This is the recommended API for accessing Schema generated classes, and
-using it might give you instant advantages with future versions of DBIC.
+Calls L<DBIx::Class::Schema/"compose_namespace"> to the target namespace,
+calls L<DBIx::Class::Schema/connection> with @db_info on the new schema,
+then injects the L<DBix::Class::ResultSetProxy> component and a
+resultset_instance classdata entry on all the new classes, in order to support
+$target_namespaces::$class->search(...) method calls.
-WARNING: Loading components into Schema classes after compose_connection
-may not cause them to be seen by the classes in your target namespace due
-to the dispatch table approach used by Class::C3. If you do this you may find
-you need to call Class::C3->reinitialize() afterwards to get the behaviour
-you expect.
+This is primarily useful when you have a specific need for class method access
+to a connection. In normal usage it is preferred to call
+L<DBIx::Class::Schema/connect> and use the resulting schema object to operate
+on L<DBIx::Class::ResultSet> objects with L<DBIx::Class::Schema/resultset> for
+more information.
=cut
my ($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 $@;
+ $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
return $schema;
}
+=head2 compose_namespace
+
+=over 4
+
+=item Arguments: $target_namespace, $additional_base_class?
+
+=item Return Value: $new_schema
+
+=back
+
+For each L<DBIx::Class::ResultSource> 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<DBIx::Class::ResultSource> 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 };
$target_class => $source->result_class, ($base ? $base : ())
);
$source->result_class($target_class);
+ $target_class->result_source_instance($source)
+ if $target_class->can('result_source_instance');
}
}
Class::C3->reinitialize();
=head2 setup_connection_class
-=head3 Arguments: <$target> <@info>
+=over 4
+
+=item Arguments: $target, @info
-Sets up a database connection class to inject between the schema
-and the subclasses the schema creates.
+=back
+
+Sets up a database connection class to inject between the schema and the
+subclasses that the schema creates.
=cut
=head2 connection
-=head3 Arguments: (@args)
+=over 4
+
+=item Arguments: @args
+
+=item Return Value: $new_schema
-Instantiates a new Storage object of type storage_type and passes the
-arguments to $storage->connect_info. Sets the connection in-place on
-the schema.
+=back
+
+Instantiates a new Storage object of type
+L<DBIx::Class::Schema/"storage_type"> and passes the arguments to
+$storage->connect_info. Sets the connection in-place on the schema. See
+L<DBIx::Class::Storage::DBI/"connect_info"> for more information.
=cut
$storage_class = 'DBIx::Class::Storage'.$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 $@;
+ $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);
=head2 connect
-=head3 Arguments: (@info)
+=over 4
+
+=item Arguments: @info
+
+=item Return Value: $new_schema
+
+=back
-Conveneience method, equivalent to $schema->clone->connection(@info)
+This is a convenience method. It is equivalent to calling
+$schema->clone->connection(@info). See L</connection> and L</clone> for more
+information.
=cut
=head2 txn_begin
-Begins a transaction (does nothing if AutoCommit is off).
+Begins a transaction (does nothing if AutoCommit is off). Equivalent to
+calling $schema->storage->txn_begin. See
+L<DBIx::Class::Storage::DBI/"txn_begin"> for more information.
=cut
=head2 txn_commit
-Commits the current transaction.
+Commits the current transaction. Equivalent to calling
+$schema->storage->txn_commit. See L<DBIx::Class::Storage::DBI/"txn_commit">
+for more information.
=cut
=head2 txn_rollback
-Rolls back the current transaction.
+Rolls back the current transaction. Equivalent to calling
+$schema->storage->txn_rollback. See
+L<DBIx::Class::Storage::DBI/"txn_rollback"> for more information.
=cut
=head2 txn_do
-=head3 Arguments: <$coderef>, [@coderef_args]
+=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>
-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.
+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 $foo = $schema->resultset('foo')->find(1);
+ my $author_rs = $schema->resultset('Author')->find(1);
+ my @titles = qw/Night Day It/;
my $coderef = sub {
- my ($foo, @bars) = @_;
-
# If any one of these fails, the entire transaction fails
- $foo->create_related('bars', {
- col => $_
- }) foreach (@bars);
+ $author_rs->create_related('books', {
+ title => $_
+ }) foreach (@titles);
- return $foo->bars;
+ return $author->books;
};
my $rs;
eval {
- $rs = $schema->txn_do($coderef, $foo, qw/foo bar baz/);
+ $rs = $schema->txn_do($coderef);
};
- if ($@) {
- my $error = $@;
- if ($error =~ /Rollback failed/) {
- die "something terrible has happened!";
- } else {
- deal_with_failed_transaction();
- die $error;
- }
+ if ($@) { # Transaction failed
+ die "something terrible has happened!" #
+ if ($@ =~ /Rollback failed/); # Rollback failed
+
+ deal_with_failed_transaction();
}
-Nested transactions work as expected (i.e. only the outermost
-transaction will issue a txn_commit on the Schema's storage)
+In a nested transaction (calling txn_do() from within a txn_do() coderef) only
+the outermost transaction will issue a L<DBIx::Class::Schema/"txn_commit"> on
+the Schema's storage, and txn_do() can be called in void, scalar and list
+context and it will behave as expected.
=cut
sub txn_do {
my ($self, $coderef, @args) = @_;
- ref $self or $self->throw_exception
- ('Cannot execute txn_do as a class method');
+ $self->storage or $self->throw_exception
+ ('txn_do called on $schema without storage');
ref $coderef eq 'CODE' or $self->throw_exception
('$coderef must be a CODE reference');
$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{}
-
+ my $wantarray = wantarray; # Need to save this since the context
+ # inside the eval{} block is independent
+ # of the context that called txn_do()
eval {
- # Need to differentiate between scalar/list context to allow for returning
- # a list in scalar context to get the size of the list
+ # Need to differentiate between scalar/list context to allow for
+ # returning a list in scalar context to get the size of the list
if ($wantarray) {
# list context
@return_values = $coderef->(@args);
my $rollback_error = $@;
my $exception_class = "DBIx::Class::Storage::NESTED_ROLLBACK_EXCEPTION";
$self->throw_exception($error) # propagate nested rollback
- if $rollback_error =~ /$exception_class/;
+ if $rollback_error =~ /$exception_class/;
- $self->throw_exception("Transaction aborted: $error. Rollback failed: ".
- $rollback_error);
+ $self->throw_exception(
+ "Transaction aborted: $error. Rollback failed: ${rollback_error}"
+ );
} else {
$self->throw_exception($error); # txn failed but rollback succeeded
}
=head2 clone
+=over 4
+
+=item Return Value: $new_schema
+
+=back
+
Clones the schema and its associated result_source objects and returns the
copy.
=head2 populate
-=head3 Arguments: ($moniker, \@data);
+=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.
+@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' ],
+ $schema->populate('Artist', [
+ [ qw/artistid name/ ],
+ [ 1, 'Popular Band' ],
+ [ 2, 'Indie Band' ],
...
]);
=head2 throw_exception
-Defaults to using Carp::Clan to report errors from user perspective.
+=over 4
+
+=item Arguments: $message
+
+=back
+
+Throws an exception. Defaults to using L<Carp::Clan> to report errors from
+user's perspective.
=cut
=head2 deploy (EXPERIMENTAL)
-Attempts to deploy the schema to the current storage using SQL::Translator.
+=over 4
+
+=item Arguments: $sqlt_args
+
+=back
+
+Attempts to deploy the schema to the current storage using L<SQL::Translator>.
Note that this feature is currently EXPERIMENTAL and may not work correctly
across all databases, or fully handle complex relationships.
+See L<SQL::Translator/METHODS> for a list of values for C<$sqlt_args>. The most
+common value for this would be C<< { add_drop_table => 1, } >> to have the SQL
+produced include a DROP TABLE statement for each table created.
+
=cut
sub deploy {
$self->storage->deploy($self, undef, $sqltargs);
}
+=head2 create_ddl_dir (EXPERIMENTAL)
+
+=over 4
+
+=item Arguments: \@databases, $version, $directory, $sqlt_args
+
+=back
+
+Creates an SQL file based on the Schema, for each of the specified
+database types, in the given directory.
+
+Note that this feature is currently EXPERIMENTAL and may not work correctly
+across all databases, or fully handle complex relationships.
+
+=cut
+
+sub create_ddl_dir
+{
+ my $self = shift;
+
+ $self->throw_exception("Can't create_ddl_dir without storage") unless $self->storage;
+ $self->storage->create_ddl_dir($self, @_);
+}
+
+=head2 ddl_filename (EXPERIMENTAL)
+
+ my $filename = $table->ddl_filename($type, $dir, $version)
+
+Creates a filename for a SQL file based on the table class name. Not
+intended for direct end user use.
+
+=cut
+
+sub ddl_filename
+{
+ my ($self, $type, $dir, $version) = @_;
+
+ my $filename = ref($self);
+ $filename =~ s/^.*:://;
+ $filename = "$dir$filename-$version-$type.sql";
+
+ return $filename;
+}
+
1;
=head1 AUTHORS