1 package DBIx::Class::Schema::Loader;
5 use base qw/DBIx::Class::Schema Class::Data::Accessor/;
6 use Carp::Clan qw/^DBIx::Class/;
7 use UNIVERSAL::require;
9 use Scalar::Util qw/ weaken /;
11 # Always remember to do all digits for the version even if they're 0
12 # i.e. first release of 0.XX *must* be 0.XX000. This avoids fBSD ports
13 # brain damage and presumably various other packaging systems too
14 our $VERSION = '0.04999_05';
16 __PACKAGE__->mk_classaccessor('_loader_args' => {});
17 __PACKAGE__->mk_classaccessors(qw/dump_to_dir _loader_invoked _loader loader_class/);
21 DBIx::Class::Schema::Loader - Dynamic definition of a DBIx::Class::Schema
26 use base qw/DBIx::Class::Schema::Loader/;
28 __PACKAGE__->loader_options(
29 constraint => '^foo.*',
33 # in seperate application code ...
37 my $schema1 = My::Schema->connect( $dsn, $user, $password, $attrs);
39 my $schema1 = "My::Schema"; $schema1->connection(as above);
43 DBIx::Class::Schema::Loader automates the definition of a
44 L<DBIx::Class::Schema> by scanning database table definitions and
45 setting up the columns, primary keys, and relationships.
47 DBIx::Class::Schema::Loader currently supports only the DBI storage type.
48 It has explicit support for L<DBD::Pg>, L<DBD::mysql>, L<DBD::DB2>,
49 L<DBD::SQLite>, and L<DBD::Oracle>. Other DBI drivers may function to
50 a greater or lesser degree with this loader, depending on how much of the
51 DBI spec they implement, and how standard their implementation is.
53 Patches to make other DBDs work correctly welcome.
55 See L<DBIx::Class::Schema::Loader::DBI::Writing> for notes on writing
56 your own vendor-specific subclass for an unsupported DBD driver.
58 This module requires L<DBIx::Class> 0.07006 or later, and obsoletes
59 the older L<DBIx::Class::Loader>.
61 This module is designed more to get you up and running quickly against
62 an existing database, or to be effective for simple situations, rather
63 than to be what you use in the long term for a complex database/project.
65 That being said, transitioning your code from a Schema generated by this
66 module to one that doesn't use this module should be straightforward and
67 painless, so don't shy away from it just for fears of the transition down
76 =item Argument: $loader_class
80 Set the loader class to be instantiated when L</connection> is called.
81 If the classname starts with "::", "DBIx::Class::Schema::Loader" is
82 prepended. Defaults to L<DBIx::Class::Schema/storage_type> (which must
83 start with "::" when using L<DBIx::Class::Schema::Loader>).
85 This is mostly useful for subclassing existing loaders or in conjunction
92 =item Argument: \%loader_options
96 Example in Synopsis above demonstrates a few common arguments. For
97 detailed information on all of the arguments, most of which are
98 only useful in fairly complex scenarios, see the
99 L<DBIx::Class::Schema::Loader::Base> documentation.
101 If you intend to use C<loader_options>, you must call
102 C<loader_options> before any connection is made, or embed the
103 C<loader_options> in the connection information itself as shown
104 below. Setting C<loader_options> after the connection has
105 already been made is useless.
112 my %args = (ref $_[0] eq 'HASH') ? %{$_[0]} : @_;
113 $self->_loader_args(\%args);
120 my $class = ref $self || $self;
122 my $args = $self->_loader_args;
124 # set up the schema/schema_class arguments
125 $args->{schema} = $self;
126 $args->{schema_class} = $class;
127 weaken($args->{schema}) if ref $self;
128 $args->{dump_directory} ||= $self->dump_to_dir;
130 # XXX this only works for relative storage_type, like ::DBI ...
131 my $impl = $self->loader_class
132 || "DBIx::Class::Schema::Loader" . $self->storage_type;
133 $impl = "DBIx::Class::Schema::Loader${impl}" if $impl =~ /^::/;
135 croak qq/Could not load storage_type loader "$impl": / .
136 qq/"$UNIVERSAL::require::ERROR"/;
138 $self->_loader($impl->new(%$args));
139 $self->_loader->load;
140 $self->_loader_invoked(1);
149 =item Arguments: @args
151 =item Return Value: $new_schema
155 See L<DBIx::Class::Schema/connection> for basic usage.
157 If the final argument is a hashref, and it contains the keys C<loader_options>
158 or C<loader_class>, those keys will be deleted, and their values value will be
159 used for the loader options or class, respectively, just as if set via the
160 L</loader_options> or L</loader_class> methods above.
162 The actual auto-loading operation (the heart of this module) will be invoked
163 as soon as the connection information is defined.
170 if($_[-1] && ref $_[-1] eq 'HASH') {
171 for my $option (qw/ loader_class loader_options /) {
172 if(my $value = delete $_[-1]->{$option}) {
173 $self->$option($value);
176 pop @_ if !keys %{$_[-1]};
179 $self = $self->next::method(@_);
181 my $class = ref $self || $self;
182 if(!$class->_loader_invoked) {
183 $self->_invoke_loader
191 See L<DBIx::Class::Schema/clone>.
198 my $clone = $self->next::method(@_);
200 if($clone->_loader_args) {
201 $clone->_loader_args->{schema} = $clone;
202 weaken($clone->_loader_args->{schema});
212 =item Argument: $directory
216 Calling this as a class method on either L<DBIx::Class::Schema::Loader>
217 or any derived schema class will cause all affected schemas to dump
218 manual versions of themselves to the named directory when they are
219 loaded. In order to be effective, this must be set before defining a
220 connection on this schema class or any derived object (as the loading
221 happens as soon as both a connection and loader_options are set, and
222 only once per class).
224 See L<DBIx::Class::Schema::Loader::Base/dump_directory> for more
225 details on the dumping mechanism.
227 This can also be set at module import time via the import option
228 C<dump_to_dir:/foo/bar> to L<DBIx::Class::Schema::Loader>, where
229 C</foo/bar> is the target directory.
233 # My::Schema isa DBIx::Class::Schema::Loader, and has connection info
234 # hardcoded in the class itself:
235 perl -MDBIx::Class::Schema::Loader=dump_to_dir:/foo/bar -MMy::Schema -e1
237 # Same, but no hard-coded connection, so we must provide one:
238 perl -MDBIx::Class::Schema::Loader=dump_to_dir:/foo/bar -MMy::Schema -e 'My::Schema->connection("dbi:Pg:dbname=foo", ...)'
240 # Or as a class method, as long as you get it done *before* defining a
241 # connection on this schema class or any derived object:
243 My::Schema->dump_to_dir('/foo/bar');
244 My::Schema->connection(........);
246 # Or as a class method on the DBIx::Class::Schema::Loader itself, which affects all
250 DBIx::Class::Schema::Loader->dump_to_dir('/foo/bar');
251 My::Schema->connection(.......);
252 My::OtherSchema->connection(.......);
254 # Another alternative to the above:
255 use DBIx::Class::Schema::Loader qw| dump_to_dir:/foo/bar |;
258 My::Schema->connection(.......);
259 My::OtherSchema->connection(.......);
266 foreach my $opt (@_) {
267 if($opt =~ m{^dump_to_dir:(.*)$}) {
268 $self->dump_to_dir($1)
270 elsif($opt eq 'make_schema_at') {
272 my $cpkg = (caller)[0];
273 *{"${cpkg}::make_schema_at"} = \&make_schema_at;
278 =head2 make_schema_at
282 =item Arguments: $schema_name, \%loader_options, \@connect_info
284 =item Return Value: $schema_name
288 This simple function allows one to create a Loader-based schema
289 in-memory on the fly without any on-disk class files of any
290 kind. When used with the C<dump_directory> option, you can
291 use this to generate a rough draft manual schema from a dsn
292 without the intermediate step of creating a physical Loader-based
295 The return value is the input class name.
297 This function can be exported/imported by the normal means, as
298 illustrated in these Examples:
300 # Simple example, creates as a new class 'New::Schema::Name' in
301 # memory in the running perl interpreter.
302 use DBIx::Class::Schema::Loader qw/ make_schema_at /;
306 [ 'dbi:Pg:dbname="foo"','postgres' ],
309 # Complex: dump loaded schema to disk, all from the commandline:
310 perl -MDBIx::Class::Schema::Loader=make_schema_at,dump_to_dir:./lib -e 'make_schema_at("New::Schema::Name", { debug => 1 }, [ "dbi:Pg:dbname=foo","postgres" ])'
312 # Same, but inside a script, and using a different way to specify the
314 use DBIx::Class::Schema::Loader qw/ make_schema_at /;
317 { debug => 1, dump_directory => './lib' },
318 [ 'dbi:Pg:dbname="foo"','postgres' ],
324 my ($target, $opts, $connect_info) = @_;
328 @{$target . '::ISA'} = qw/DBIx::Class::Schema::Loader/;
331 $target->loader_options($opts);
332 $target->connection(@$connect_info);
339 =item Return Value: @new_monikers
343 Re-scans the database for newly added tables since the initial
344 load, and adds them to the schema at runtime, including relationships,
345 etc. Does not process drops or changes.
347 Returns a list of the new monikers added.
351 sub rescan { my $self = shift; $self->_loader->rescan($self) }
355 Using the example in L<DBIx::Class::Manual::ExampleSchema> as a basis
356 replace the DB::Main with the following code:
360 use base qw/DBIx::Class::Schema::Loader/;
362 __PACKAGE__->loader_options(
365 __PACKAGE__->connection('dbi:SQLite:example.db');
369 and remove the Main directory tree (optional). Every thing else
374 =head2 Multiple Database Schemas
376 Currently the loader is limited to working within a single schema
377 (using the database vendors' definition of "schema"). If you
378 have a multi-schema database with inter-schema relationships (which
379 is easy to do in PostgreSQL or DB2 for instance), you only get to
380 automatically load the tables of one schema, and any relationships
381 to tables in other schemas will be silently ignored.
383 At some point in the future, an intelligent way around this might be
384 devised, probably by allowing the C<db_schema> option to be an
385 arrayref of schemas to load.
387 In "normal" L<DBIx::Class::Schema> usage, manually-defined
388 source classes and relationships have no problems crossing vendor schemas.
392 Brandon Black, C<blblack@gmail.com>
394 Based on L<DBIx::Class::Loader> by Sebastian Riedel
396 Based upon the work of IKEBE Tomohiro
400 Matt S Trout, all of the #dbix-class folks, and everyone who's ever sent
401 in a bug report or suggestion.
405 This library is free software; you can redistribute it and/or modify it under
406 the same terms as Perl itself.
410 L<DBIx::Class>, L<DBIx::Class::Manual::ExampleSchema>