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('dump_to_dir');
18 __PACKAGE__->mk_classaccessor('_loader_args' => {});
19 __PACKAGE__->mk_classaccessor('_loader_invoked');
23 DBIx::Class::Schema::Loader - Dynamic definition of a DBIx::Class::Schema
28 use base qw/DBIx::Class::Schema::Loader/;
30 __PACKAGE__->loader_options(
31 constraint => '^foo.*',
35 # in seperate application code ...
39 my $schema1 = My::Schema->connect( $dsn, $user, $password, $attrs);
41 my $schema1 = "My::Schema"; $schema1->connection(as above);
45 DBIx::Class::Schema::Loader automates the definition of a
46 L<DBIx::Class::Schema> by scanning database table definitions and
47 setting up the columns, primary keys, and relationships.
49 DBIx::Class::Schema::Loader currently supports only the DBI storage type.
50 It has explicit support for L<DBD::Pg>, L<DBD::mysql>, L<DBD::DB2>, and
51 L<DBD::SQLite>. Other DBI drivers may function to a greater or lesser
52 degree with this loader, depending on how much of the DBI spec they
53 implement, and how standard their implementation is. Patches to make
54 other DBDs work correctly welcome.
56 See L<DBIx::Class::Schema::Loader::DBI::Writing> for notes on writing
57 your own vendor-specific subclass for an unsupported DBD driver.
59 This module requires L<DBIx::Class> 0.06 or later, and obsoletes
60 the older L<DBIx::Class::Loader>.
62 This module is designed more to get you up and running quickly against
63 an existing database, or to be effective for simple situations, rather
64 than to be what you use in the long term for a complex database/project.
66 That being said, transitioning your code from a Schema generated by this
67 module to one that doesn't use this module should be straightforward and
68 painless, so don't shy away from it just for fears of the transition down
75 Example in Synopsis above demonstrates a few common arguments. For
76 detailed information on all of the arguments, most of which are
77 only useful in fairly complex scenarios, see the
78 L<DBIx::Class::Schema::Loader::Base> documentation.
80 One must call C<loader_options> before any connection is made,
81 or embed the C<loader_options> in the connection information itself
82 as shown 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 $impl->new(%$args)->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 Using the example in L<DBIx::Class::Manual::ExampleSchema> as a basis
290 replace the DB::Main with the following code:
294 use base qw/DBIx::Class::Schema::Loader/;
296 __PACKAGE__->loader_options(
299 __PACKAGE__->connection('dbi:SQLite:example.db');
303 and remove the Main directory tree (optional). Every thing else
308 =head2 Multiple Database Schemas
310 Currently the loader is limited to working within a single schema
311 (using the database vendors' definition of "schema"). If you
312 have a multi-schema database with inter-schema relationships (which
313 is easy to do in PostgreSQL or DB2 for instance), you only get to
314 automatically load the tables of one schema, and any relationships
315 to tables in other schemas will be silently ignored.
317 At some point in the future, an intelligent way around this might be
318 devised, probably by allowing the C<db_schema> option to be an
319 arrayref of schemas to load.
321 In "normal" L<DBIx::Class::Schema> usage, manually-defined
322 source classes and relationships have no problems crossing vendor schemas.
326 Brandon Black, C<blblack@gmail.com>
328 Based on L<DBIx::Class::Loader> by Sebastian Riedel
330 Based upon the work of IKEBE Tomohiro
334 Matt S Trout, all of the #dbix-class folks, and everyone who's ever sent
335 in a bug report or suggestion.
339 This library is free software; you can redistribute it and/or modify it under
340 the same terms as Perl itself.
344 L<DBIx::Class>, L<DBIx::Class::Manual::ExampleSchema>