1 package DBIx::Class::Schema::Loader;
5 use base qw/DBIx::Class::Schema/;
6 use base qw/Class::Data::Accessor/;
7 use Carp::Clan qw/^DBIx::Class/;
8 use UNIVERSAL::require;
10 use Scalar::Util qw/ weaken /;
12 # Always remember to do all digits for the version even if they're 0
13 # i.e. first release of 0.XX *must* be 0.XX000. This avoids fBSD ports
14 # brain damage and presumably various other packaging systems too
15 our $VERSION = '0.03999_01';
17 __PACKAGE__->mk_classaccessor('_loader_args' => {});
18 __PACKAGE__->mk_classaccessors(qw/dump_to_dir _loader_invoked _loader/);
22 DBIx::Class::Schema::Loader - Dynamic definition of a DBIx::Class::Schema
27 use base qw/DBIx::Class::Schema::Loader/;
29 __PACKAGE__->loader_options(
30 constraint => '^foo.*',
34 # in seperate application code ...
38 my $schema1 = My::Schema->connect( $dsn, $user, $password, $attrs);
40 my $schema1 = "My::Schema"; $schema1->connection(as above);
44 DBIx::Class::Schema::Loader automates the definition of a
45 L<DBIx::Class::Schema> by scanning database table definitions and
46 setting up the columns, primary keys, and relationships.
48 DBIx::Class::Schema::Loader currently supports only the DBI storage type.
49 It has explicit support for L<DBD::Pg>, L<DBD::mysql>, L<DBD::DB2>, and
50 L<DBD::SQLite>. Other DBI drivers may function to a greater or lesser
51 degree with this loader, depending on how much of the DBI spec they
52 implement, and how standard their implementation is. Patches to make
53 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> 0.06 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 One must call C<loader_options> before any connection is made,
80 or embed the C<loader_options> in the connection information itself
81 as shown below. Setting C<loader_options> after the connection has
82 already been made is useless.
89 my %args = (ref $_[0] eq 'HASH') ? %{$_[0]} : @_;
90 $self->_loader_args(\%args);
97 my $class = ref $self || $self;
99 my $args = $self->_loader_args;
101 # set up the schema/schema_class arguments
102 $args->{schema} = $self;
103 $args->{schema_class} = $class;
104 weaken($args->{schema}) if ref $self;
105 $args->{dump_directory} ||= $self->dump_to_dir;
107 # XXX this only works for relative storage_type, like ::DBI ...
108 my $impl = "DBIx::Class::Schema::Loader" . $self->storage_type;
110 croak qq/Could not load storage_type loader "$impl": / .
111 qq/"$UNIVERSAL::require::ERROR"/;
113 $self->_loader($impl->new(%$args));
114 $self->_loader->load;
115 $self->_loader_invoked(1);
122 See L<DBIx::Class::Schema> for basic usage.
124 If the final argument is a hashref, and it contains a key C<loader_options>,
125 that key will be deleted, and its value will be used for the loader options,
126 just as if set via the L</loader_options> method above.
128 The actual auto-loading operation (the heart of this module) will be invoked
129 as soon as the connection information is defined.
136 if($_[-1] && ref $_[-1] eq 'HASH') {
137 if(my $loader_opts = delete $_[-1]->{loader_options}) {
138 $self->loader_options($loader_opts);
139 pop @_ if !keys %{$_[-1]};
143 $self = $self->next::method(@_);
145 my $class = ref $self || $self;
146 if(!$class->_loader_invoked) {
147 $self->_invoke_loader
155 See L<DBIx::Class::Schema>.
162 my $clone = $self->next::method(@_);
164 if($clone->_loader_args) {
165 $clone->_loader_args->{schema} = $clone;
166 weaken($clone->_loader_args->{schema});
174 Argument: directory name.
176 Calling this as a class method on either L<DBIx::Class::Schema::Loader>
177 or any derived schema class will cause all affected schemas to dump
178 manual versions of themselves to the named directory when they are
179 loaded. In order to be effective, this must be set before defining a
180 connection on this schema class or any derived object (as the loading
181 happens as soon as both a connection and loader_options are set, and
182 only once per class).
184 See L<DBIx::Class::Schema::Loader::Base/dump_directory> for more
185 details on the dumping mechanism.
187 This can also be set at module import time via the import option
188 C<dump_to_dir:/foo/bar> to L<DBIx::Class::Schema::Loader>, where
189 C</foo/bar> is the target directory.
193 # My::Schema isa DBIx::Class::Schema::Loader, and has connection info
194 # hardcoded in the class itself:
195 perl -MDBIx::Class::Schema::Loader=dump_to_dir:/foo/bar -MMy::Schema -e1
197 # Same, but no hard-coded connection, so we must provide one:
198 perl -MDBIx::Class::Schema::Loader=dump_to_dir:/foo/bar -MMy::Schema -e 'My::Schema->connection("dbi:Pg:dbname=foo", ...)'
200 # Or as a class method, as long as you get it done *before* defining a
201 # connection on this schema class or any derived object:
203 My::Schema->dump_to_dir('/foo/bar');
204 My::Schema->connection(........);
206 # Or as a class method on the DBIx::Class::Schema::Loader itself, which affects all
210 DBIx::Class::Schema::Loader->dump_to_dir('/foo/bar');
211 My::Schema->connection(.......);
212 My::OtherSchema->connection(.......);
214 # Another alternative to the above:
215 use DBIx::Class::Schema::Loader qw| dump_to_dir:/foo/bar |;
218 My::Schema->connection(.......);
219 My::OtherSchema->connection(.......);
226 foreach my $opt (@_) {
227 if($opt =~ m{^dump_to_dir:(.*)$}) {
228 $self->dump_to_dir($1)
230 elsif($opt eq 'make_schema_at') {
232 my $cpkg = (caller)[0];
233 *{"${cpkg}::make_schema_at"} = \&make_schema_at;
238 =head2 make_schema_at
240 This simple function allows one to create a Loader-based schema
241 in-memory on the fly without any on-disk class files of any
242 kind. When used with the C<dump_directory> option, you can
243 use this to generate a rough draft manual schema from a dsn
244 without the intermediate step of creating a physical Loader-based
247 The return value is the input class name.
249 This function can be exported/imported by the normal means, as
250 illustrated in these Examples:
252 # Simple example, creates as a new class 'New::Schema::Name' in
253 # memory in the running perl interpreter.
254 use DBIx::Class::Schema::Loader qw/ make_schema_at /;
258 [ 'dbi:Pg:dbname="foo"','postgres' ],
261 # Complex: dump loaded schema to disk, all from the commandline:
262 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" ])'
264 # Same, but inside a script, and using a different way to specify the
266 use DBIx::Class::Schema::Loader qw/ make_schema_at /;
269 { debug => 1, dump_directory => './lib' },
270 [ 'dbi:Pg:dbname="foo"','postgres' ],
276 my ($target, $opts, $connect_info) = @_;
280 @{$target . '::ISA'} = qw/DBIx::Class::Schema::Loader/;
283 $target->loader_options($opts);
284 $target->connection(@$connect_info);
289 Re-scans the database for newly added tables since the initial
290 load, and adds them to the schema at runtime, including relationships,
291 etc. Does not process drops or changes.
293 Returns a list of the new monikers added.
297 sub rescan { my $self = shift; $self->_loader->rescan($self) }
301 Using the example in L<DBIx::Class::Manual::ExampleSchema> as a basis
302 replace the DB::Main with the following code:
306 use base qw/DBIx::Class::Schema::Loader/;
308 __PACKAGE__->loader_options(
311 __PACKAGE__->connection('dbi:SQLite:example.db');
315 and remove the Main directory tree (optional). Every thing else
320 =head2 Multiple Database Schemas
322 Currently the loader is limited to working within a single schema
323 (using the database vendors' definition of "schema"). If you
324 have a multi-schema database with inter-schema relationships (which
325 is easy to do in PostgreSQL or DB2 for instance), you only get to
326 automatically load the tables of one schema, and any relationships
327 to tables in other schemas will be silently ignored.
329 At some point in the future, an intelligent way around this might be
330 devised, probably by allowing the C<db_schema> option to be an
331 arrayref of schemas to load.
333 In "normal" L<DBIx::Class::Schema> usage, manually-defined
334 source classes and relationships have no problems crossing vendor schemas.
338 Brandon Black, C<blblack@gmail.com>
340 Based on L<DBIx::Class::Loader> by Sebastian Riedel
342 Based upon the work of IKEBE Tomohiro
346 Matt S Trout, all of the #dbix-class folks, and everyone who's ever sent
347 in a bug report or suggestion.
351 This library is free software; you can redistribute it and/or modify it under
352 the same terms as Perl itself.
356 L<DBIx::Class>, L<DBIx::Class::Manual::ExampleSchema>