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 = '0.04006';
16 __PACKAGE__->mk_classaccessor('_loader_args' => {});
17 __PACKAGE__->mk_classaccessors(qw/dump_to_dir _loader_invoked _loader/);
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
74 Example in Synopsis above demonstrates a few common arguments. For
75 detailed information on all of the arguments, most of which are
76 only useful in fairly complex scenarios, see the
77 L<DBIx::Class::Schema::Loader::Base> documentation.
79 If you intend to use C<loader_options>, you must call
80 C<loader_options> before any connection is made, or embed the
81 C<loader_options> in the connection information itself as shown
82 below. Setting C<loader_options> after the connection has
83 already been made is useless.
90 my %args = (ref $_[0] eq 'HASH') ? %{$_[0]} : @_;
91 $self->_loader_args(\%args);
98 my $class = ref $self || $self;
100 my $args = $self->_loader_args;
102 # set up the schema/schema_class arguments
103 $args->{schema} = $self;
104 $args->{schema_class} = $class;
105 weaken($args->{schema}) if ref $self;
106 $args->{dump_directory} ||= $self->dump_to_dir;
108 # XXX this only works for relative storage_type, like ::DBI ...
109 my $impl = "DBIx::Class::Schema::Loader" . $self->storage_type;
111 croak qq/Could not load storage_type loader "$impl": / .
112 qq/"$UNIVERSAL::require::ERROR"/;
114 $self->_loader($impl->new(%$args));
115 $self->_loader->load;
116 $self->_loader_invoked(1);
123 See L<DBIx::Class::Schema> for basic usage.
125 If the final argument is a hashref, and it contains a key C<loader_options>,
126 that key will be deleted, and its value will be used for the loader options,
127 just as if set via the L</loader_options> method above.
129 The actual auto-loading operation (the heart of this module) will be invoked
130 as soon as the connection information is defined.
137 if($_[-1] && ref $_[-1] eq 'HASH') {
138 if(my $loader_opts = delete $_[-1]->{loader_options}) {
139 $self->loader_options($loader_opts);
140 pop @_ if !keys %{$_[-1]};
144 $self = $self->next::method(@_);
146 my $class = ref $self || $self;
147 if(!$class->_loader_invoked) {
148 $self->_invoke_loader
156 See L<DBIx::Class::Schema>.
163 my $clone = $self->next::method(@_);
165 if($clone->_loader_args) {
166 $clone->_loader_args->{schema} = $clone;
167 weaken($clone->_loader_args->{schema});
175 Argument: directory name.
177 Calling this as a class method on either L<DBIx::Class::Schema::Loader>
178 or any derived schema class will cause all affected schemas to dump
179 manual versions of themselves to the named directory when they are
180 loaded. In order to be effective, this must be set before defining a
181 connection on this schema class or any derived object (as the loading
182 happens as soon as both a connection and loader_options are set, and
183 only once per class).
185 See L<DBIx::Class::Schema::Loader::Base/dump_directory> for more
186 details on the dumping mechanism.
188 This can also be set at module import time via the import option
189 C<dump_to_dir:/foo/bar> to L<DBIx::Class::Schema::Loader>, where
190 C</foo/bar> is the target directory.
194 # My::Schema isa DBIx::Class::Schema::Loader, and has connection info
195 # hardcoded in the class itself:
196 perl -MDBIx::Class::Schema::Loader=dump_to_dir:/foo/bar -MMy::Schema -e1
198 # Same, but no hard-coded connection, so we must provide one:
199 perl -MDBIx::Class::Schema::Loader=dump_to_dir:/foo/bar -MMy::Schema -e 'My::Schema->connection("dbi:Pg:dbname=foo", ...)'
201 # Or as a class method, as long as you get it done *before* defining a
202 # connection on this schema class or any derived object:
204 My::Schema->dump_to_dir('/foo/bar');
205 My::Schema->connection(........);
207 # Or as a class method on the DBIx::Class::Schema::Loader itself, which affects all
211 DBIx::Class::Schema::Loader->dump_to_dir('/foo/bar');
212 My::Schema->connection(.......);
213 My::OtherSchema->connection(.......);
215 # Another alternative to the above:
216 use DBIx::Class::Schema::Loader qw| dump_to_dir:/foo/bar |;
219 My::Schema->connection(.......);
220 My::OtherSchema->connection(.......);
227 foreach my $opt (@_) {
228 if($opt =~ m{^dump_to_dir:(.*)$}) {
229 $self->dump_to_dir($1)
231 elsif($opt eq 'make_schema_at') {
233 my $cpkg = (caller)[0];
234 *{"${cpkg}::make_schema_at"} = \&make_schema_at;
239 =head2 make_schema_at
241 This simple function allows one to create a Loader-based schema
242 in-memory on the fly without any on-disk class files of any
243 kind. When used with the C<dump_directory> option, you can
244 use this to generate a rough draft manual schema from a dsn
245 without the intermediate step of creating a physical Loader-based
248 The return value is the input class name.
250 This function can be exported/imported by the normal means, as
251 illustrated in these Examples:
253 # Simple example, creates as a new class 'New::Schema::Name' in
254 # memory in the running perl interpreter.
255 use DBIx::Class::Schema::Loader qw/ make_schema_at /;
259 [ 'dbi:Pg:dbname="foo"','postgres' ],
262 # Complex: dump loaded schema to disk, all from the commandline:
263 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" ])'
265 # Same, but inside a script, and using a different way to specify the
267 use DBIx::Class::Schema::Loader qw/ make_schema_at /;
270 { debug => 1, dump_directory => './lib' },
271 [ 'dbi:Pg:dbname="foo"','postgres' ],
277 my ($target, $opts, $connect_info) = @_;
281 @{$target . '::ISA'} = qw/DBIx::Class::Schema::Loader/;
284 $target->loader_options($opts);
285 $target->connection(@$connect_info);
290 Re-scans the database for newly added tables since the initial
291 load, and adds them to the schema at runtime, including relationships,
292 etc. Does not process drops or changes.
294 Returns a list of the new monikers added.
298 sub rescan { my $self = shift; $self->_loader->rescan($self) }
302 Using the example in L<DBIx::Class::Manual::ExampleSchema> as a basis
303 replace the DB::Main with the following code:
307 use base qw/DBIx::Class::Schema::Loader/;
309 __PACKAGE__->loader_options(
312 __PACKAGE__->connection('dbi:SQLite:example.db');
316 and remove the Main directory tree (optional). Every thing else
321 =head2 Multiple Database Schemas
323 Currently the loader is limited to working within a single schema
324 (using the database vendors' definition of "schema"). If you
325 have a multi-schema database with inter-schema relationships (which
326 is easy to do in PostgreSQL or DB2 for instance), you only get to
327 automatically load the tables of one schema, and any relationships
328 to tables in other schemas will be silently ignored.
330 At some point in the future, an intelligent way around this might be
331 devised, probably by allowing the C<db_schema> option to be an
332 arrayref of schemas to load.
334 In "normal" L<DBIx::Class::Schema> usage, manually-defined
335 source classes and relationships have no problems crossing vendor schemas.
339 Brandon Black, C<blblack@gmail.com>
341 Based on L<DBIx::Class::Loader> by Sebastian Riedel
343 Based upon the work of IKEBE Tomohiro
347 Matt S Trout, all of the #dbix-class folks, and everyone who's ever sent
348 in a bug report or suggestion.
352 This library is free software; you can redistribute it and/or modify it under
353 the same terms as Perl itself.
357 L<DBIx::Class>, L<DBIx::Class::Manual::ExampleSchema>