create now on resultset as well
[dbsrgits/DBIx-Class-Historic.git] / lib / DBIx / Class / Schema.pm
CommitLineData
a02675cd 1package DBIx::Class::Schema;
2
3use strict;
4use warnings;
63e9583a 5use DBIx::Class::DB;
a02675cd 6
41a6f8c0 7use base qw/DBIx::Class/;
a02675cd 8
42a1aaa1 9__PACKAGE__->load_components(qw/Exception/);
74b92d9a 10__PACKAGE__->mk_classdata('class_registrations' => {});
d7156e50 11__PACKAGE__->mk_classdata('storage_type' => 'DBI');
12__PACKAGE__->mk_classdata('storage');
a02675cd 13
c2da098a 14=head1 NAME
15
16DBIx::Class::Schema - composable schemas
17
18=head1 SYNOPSIS
19
03312470 20in My/Schema.pm
c2da098a 21
22 package My::Schema;
23
24 use base qw/DBIx::Class::Schema/;
25
26 __PACKAGE__->load_classes(qw/Foo Bar Baz/);
27
03312470 28in My/Schema/Foo.pm
c2da098a 29
30 package My::Schema::Foo;
31
03312470 32 use base qw/DBIx::Class/;
c2da098a 33
54540863 34 __PACKAGE__->load_components(qw/PK::Auto::Pg Core/); # for example
c2da098a 35 __PACKAGE__->table('foo');
36 ...
37
03312470 38in My/DB.pm
c2da098a 39
40 use My::Schema;
41
42 My::Schema->compose_connection('My::DB', $dsn, $user, $pass, $attrs);
43
03312470 44then in app code
c2da098a 45
656796f2 46 my @obj = My::DB::Foo->search({}); # My::DB::Foo isa My::Schema::Foo My::DB
c2da098a 47
48=head1 DESCRIPTION
49
429bd4f1 50Creates database classes based on a schema. This allows you to have more than
51one concurrent connection using the same database classes, by making
52subclasses under a new namespace for each connection. If you only need one
53class, you should probably use L<DBIx::Class::DB> directly instead.
54
03312470 55NB: If you're used to L<Class::DBI> it's worth reading the L</SYNOPSIS>
56carefully as DBIx::Class does things a little differently. Note in
57particular which module inherits off which.
58
c2da098a 59=head1 METHODS
60
130c6439 61=head2 register_class <component> <component_class>
076652e8 62
63Registers the class in the schema's class_registrations. This is a hash
429bd4f1 64containing database classes, keyed by their monikers. It's used by
076652e8 65compose_connection to create/modify all the existing database classes.
66
c2da098a 67=cut
68
a02675cd 69sub register_class {
70 my ($class, $name, $to_register) = @_;
74b92d9a 71 my %reg = %{$class->class_registrations};
a02675cd 72 $reg{$name} = $to_register;
74b92d9a 73 $class->class_registrations(\%reg);
74}
75
130c6439 76=head2 registered_classes
076652e8 77
78Simple read-only accessor for the schema's registered classes. See
79register_class above if you want to modify it.
80
81
82=cut
83
74b92d9a 84sub registered_classes {
85 return values %{shift->class_registrations};
a02675cd 86}
87
130c6439 88=head2 load_classes [<classes>, (<class>, <class>), {<namespace> => [<classes>]}]
076652e8 89
429bd4f1 90Uses L<Module::Find> to find all classes under the database class' namespace,
91or uses the classes you select. Then it loads the component (using L<use>),
92and registers them (using B<register_class>);
076652e8 93
5ce32fc1 94It is possible to comment out classes with a leading '#', but note that perl
95will think it's a mistake (trying to use a comment in a qw list) so you'll
96need to add "no warnings 'qw';" before your load_classes call.
97
076652e8 98=cut
99
a02675cd 100sub load_classes {
5ce32fc1 101 my ($class, @params) = @_;
102
103 my %comps_for;
104
105 if (@params) {
106 foreach my $param (@params) {
107 if (ref $param eq 'ARRAY') {
108 # filter out commented entries
109 my @modules = grep { $_ !~ /^#/ } @$param;
110
111 push (@{$comps_for{$class}}, @modules);
112 }
113 elsif (ref $param eq 'HASH') {
114 # more than one namespace possible
115 for my $comp ( keys %$param ) {
116 # filter out commented entries
117 my @modules = grep { $_ !~ /^#/ } @{$param->{$comp}};
118
119 push (@{$comps_for{$comp}}, @modules);
120 }
121 }
122 else {
123 # filter out commented entries
124 push (@{$comps_for{$class}}, $param) if $param !~ /^#/;
125 }
126 }
127 } else {
41a6f8c0 128 eval "require Module::Find;";
129 $class->throw("No arguments to load_classes and couldn't load".
130 " Module::Find ($@)") if $@;
5ce32fc1 131 my @comp = map { substr $_, length "${class}::" } Module::Find::findallmod($class);
132 $comps_for{$class} = \@comp;
41a6f8c0 133 }
5ce32fc1 134
135 foreach my $prefix (keys %comps_for) {
136 foreach my $comp (@{$comps_for{$prefix}||[]}) {
137 my $comp_class = "${prefix}::${comp}";
5ce32fc1 138 eval "use $comp_class"; # If it fails, assume the user fixed it
139 $class->register_class($comp => $comp_class);
140 }
a02675cd 141 }
142}
143
130c6439 144=head2 compose_connection <target> <@db_info>
429bd4f1 145
146This is the most important method in this class. it takes a target namespace,
147as well as dbh connection info, and creates a L<DBIx::Class::DB> class as
148well as subclasses for each of your database classes in this namespace, using
149this connection.
076652e8 150
54540863 151It will also setup a ->class method on the target class, which lets you
8c130052 152resolve database classes based on the schema component name, for example
153
54540863 154 MyApp::DB->class('Foo') # returns MyApp::DB::Foo,
8c130052 155 # which ISA MyApp::Schema::Foo
156
157This is the recommended API for accessing Schema generated classes, and
158using it might give you instant advantages with future versions of DBIC.
159
54540863 160WARNING: Loading components into Schema classes after compose_connection
161may not cause them to be seen by the classes in your target namespace due
162to the dispatch table approach used by Class::C3. If you do this you may find
163you need to call Class::C3->reinitialize() afterwards to get the behaviour
164you expect.
165
076652e8 166=cut
167
a02675cd 168sub compose_connection {
169 my ($class, $target, @info) = @_;
11b78bd6 170 my $conn_class = "${target}::_db";
171 $class->setup_connection_class($conn_class, @info);
e678398e 172 $class->compose_namespace($target, $conn_class);
173}
174
175sub compose_namespace {
176 my ($class, $target, $base) = @_;
74b92d9a 177 my %reg = %{ $class->class_registrations };
11b78bd6 178 my %target;
179 my %map;
a02675cd 180 while (my ($comp, $comp_class) = each %reg) {
181 my $target_class = "${target}::${comp}";
e678398e 182 $class->inject_base($target_class, $comp_class, $base);
11b78bd6 183 @map{$comp, $comp_class} = ($target_class, $target_class);
b7951443 184 }
11b78bd6 185 {
186 no strict 'refs';
187 *{"${target}::class"} =
188 sub {
189 my ($class, $to_map) = @_;
190 return $map{$to_map};
191 };
d3dec624 192 *{"${target}::classes"} = sub { return \%map; };
11b78bd6 193 }
e678398e 194 $base->class_resolver($target);
b7951443 195}
196
130c6439 197=head2 setup_connection_class <$target> <@info>
076652e8 198
429bd4f1 199Sets up a database connection class to inject between the schema
200and the subclasses the schema creates.
201
076652e8 202=cut
203
b7951443 204sub setup_connection_class {
205 my ($class, $target, @info) = @_;
63e9583a 206 $class->inject_base($target => 'DBIx::Class::DB');
207 #$target->load_components('DB');
b7951443 208 $target->connection(@info);
209}
210
a02675cd 2111;
c2da098a 212
c2da098a 213=head1 AUTHORS
214
daec44b8 215Matt S. Trout <mst@shadowcatsystems.co.uk>
c2da098a 216
217=head1 LICENSE
218
219You may distribute this code under the same terms as Perl itself.
220
221=cut
222