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_04';
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 = $args->{loader_class}
110 || "DBIx::Class::Schema::Loader" . $self->storage_type;
112 croak qq/Could not load storage_type loader "$impl": / .
113 qq/"$UNIVERSAL::require::ERROR"/;
115 $self->_loader($impl->new(%$args));
116 $self->_loader->load;
117 $self->_loader_invoked(1);
124 See L<DBIx::Class::Schema> for basic usage.
126 If the final argument is a hashref, and it contains a key C<loader_options>,
127 that key will be deleted, and its value will be used for the loader options,
128 just as if set via the L</loader_options> method above.
130 The actual auto-loading operation (the heart of this module) will be invoked
131 as soon as the connection information is defined.
138 if($_[-1] && ref $_[-1] eq 'HASH') {
139 if(my $loader_opts = delete $_[-1]->{loader_options}) {
140 $self->loader_options($loader_opts);
141 pop @_ if !keys %{$_[-1]};
145 $self = $self->next::method(@_);
147 my $class = ref $self || $self;
148 if(!$class->_loader_invoked) {
149 $self->_invoke_loader
157 See L<DBIx::Class::Schema>.
164 my $clone = $self->next::method(@_);
166 if($clone->_loader_args) {
167 $clone->_loader_args->{schema} = $clone;
168 weaken($clone->_loader_args->{schema});
176 Argument: directory name.
178 Calling this as a class method on either L<DBIx::Class::Schema::Loader>
179 or any derived schema class will cause all affected schemas to dump
180 manual versions of themselves to the named directory when they are
181 loaded. In order to be effective, this must be set before defining a
182 connection on this schema class or any derived object (as the loading
183 happens as soon as both a connection and loader_options are set, and
184 only once per class).
186 See L<DBIx::Class::Schema::Loader::Base/dump_directory> for more
187 details on the dumping mechanism.
189 This can also be set at module import time via the import option
190 C<dump_to_dir:/foo/bar> to L<DBIx::Class::Schema::Loader>, where
191 C</foo/bar> is the target directory.
195 # My::Schema isa DBIx::Class::Schema::Loader, and has connection info
196 # hardcoded in the class itself:
197 perl -MDBIx::Class::Schema::Loader=dump_to_dir:/foo/bar -MMy::Schema -e1
199 # Same, but no hard-coded connection, so we must provide one:
200 perl -MDBIx::Class::Schema::Loader=dump_to_dir:/foo/bar -MMy::Schema -e 'My::Schema->connection("dbi:Pg:dbname=foo", ...)'
202 # Or as a class method, as long as you get it done *before* defining a
203 # connection on this schema class or any derived object:
205 My::Schema->dump_to_dir('/foo/bar');
206 My::Schema->connection(........);
208 # Or as a class method on the DBIx::Class::Schema::Loader itself, which affects all
212 DBIx::Class::Schema::Loader->dump_to_dir('/foo/bar');
213 My::Schema->connection(.......);
214 My::OtherSchema->connection(.......);
216 # Another alternative to the above:
217 use DBIx::Class::Schema::Loader qw| dump_to_dir:/foo/bar |;
220 My::Schema->connection(.......);
221 My::OtherSchema->connection(.......);
228 foreach my $opt (@_) {
229 if($opt =~ m{^dump_to_dir:(.*)$}) {
230 $self->dump_to_dir($1)
232 elsif($opt eq 'make_schema_at') {
234 my $cpkg = (caller)[0];
235 *{"${cpkg}::make_schema_at"} = \&make_schema_at;
240 =head2 make_schema_at
242 This simple function allows one to create a Loader-based schema
243 in-memory on the fly without any on-disk class files of any
244 kind. When used with the C<dump_directory> option, you can
245 use this to generate a rough draft manual schema from a dsn
246 without the intermediate step of creating a physical Loader-based
249 The return value is the input class name.
251 This function can be exported/imported by the normal means, as
252 illustrated in these Examples:
254 # Simple example, creates as a new class 'New::Schema::Name' in
255 # memory in the running perl interpreter.
256 use DBIx::Class::Schema::Loader qw/ make_schema_at /;
260 [ 'dbi:Pg:dbname="foo"','postgres' ],
263 # Complex: dump loaded schema to disk, all from the commandline:
264 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" ])'
266 # Same, but inside a script, and using a different way to specify the
268 use DBIx::Class::Schema::Loader qw/ make_schema_at /;
271 { debug => 1, dump_directory => './lib' },
272 [ 'dbi:Pg:dbname="foo"','postgres' ],
278 my ($target, $opts, $connect_info) = @_;
282 @{$target . '::ISA'} = qw/DBIx::Class::Schema::Loader/;
285 $target->loader_options($opts);
286 $target->connection(@$connect_info);
291 Re-scans the database for newly added tables since the initial
292 load, and adds them to the schema at runtime, including relationships,
293 etc. Does not process drops or changes.
295 Returns a list of the new monikers added.
299 sub rescan { my $self = shift; $self->_loader->rescan($self) }
303 Using the example in L<DBIx::Class::Manual::ExampleSchema> as a basis
304 replace the DB::Main with the following code:
308 use base qw/DBIx::Class::Schema::Loader/;
310 __PACKAGE__->loader_options(
313 __PACKAGE__->connection('dbi:SQLite:example.db');
317 and remove the Main directory tree (optional). Every thing else
322 =head2 Multiple Database Schemas
324 Currently the loader is limited to working within a single schema
325 (using the database vendors' definition of "schema"). If you
326 have a multi-schema database with inter-schema relationships (which
327 is easy to do in PostgreSQL or DB2 for instance), you only get to
328 automatically load the tables of one schema, and any relationships
329 to tables in other schemas will be silently ignored.
331 At some point in the future, an intelligent way around this might be
332 devised, probably by allowing the C<db_schema> option to be an
333 arrayref of schemas to load.
335 In "normal" L<DBIx::Class::Schema> usage, manually-defined
336 source classes and relationships have no problems crossing vendor schemas.
340 Brandon Black, C<blblack@gmail.com>
342 Based on L<DBIx::Class::Loader> by Sebastian Riedel
344 Based upon the work of IKEBE Tomohiro
348 Matt S Trout, all of the #dbix-class folks, and everyone who's ever sent
349 in a bug report or suggestion.
353 This library is free software; you can redistribute it and/or modify it under
354 the same terms as Perl itself.
358 L<DBIx::Class>, L<DBIx::Class::Manual::ExampleSchema>