Move scary stuff to its own class

[dbsrgits/DBIx-Class.git] / lib / DBIx / Class / ResultSource / View.pm

diff --git a/lib/DBIx/Class/ResultSource/View.pm b/lib/DBIx/Class/ResultSource/View.pm
index 7d6ec12..232cc2f 100644 (file)
--- a/lib/DBIx/Class/ResultSource/View.pm
+++ b/lib/DBIx/Class/ResultSource/View.pm
@@ -7,42 +7,175 @@ use DBIx::Class::ResultSet;
 
 use base qw/DBIx::Class/;
 __PACKAGE__->load_components(qw/ResultSource/);
-
-
-  _columns _primaries _unique_constraints name resultset_attributes
-  schema from _relationships column_info_from_storage source_info
-  source_name/);
-
+__PACKAGE__->mk_group_accessors(
+    'simple' => qw(is_virtual view_definition deploy_depends_on) );
 
 =head1 NAME
 
-DBIx::Class::ResultSource::Table - Table object
+DBIx::Class::ResultSource::View - ResultSource object representing a view
 
 =head1 SYNOPSIS
 
+  package MyApp::Schema::Result::Year2000CDs;
+
+  use base qw/DBIx::Class::Core/;
+
+  __PACKAGE__->table_class('DBIx::Class::ResultSource::View');
+
+  __PACKAGE__->table('year2000cds');
+  __PACKAGE__->result_source_instance->is_virtual(1);
+  __PACKAGE__->result_source_instance->view_definition(
+      "SELECT cdid, artist, title FROM cd WHERE year ='2000'"
+  );
+  __PACKAGE__->add_columns(
+    'cdid' => {
+      data_type => 'integer',
+      is_auto_increment => 1,
+    },
+    'artist' => {
+      data_type => 'integer',
+    },
+    'title' => {
+      data_type => 'varchar',
+      size      => 100,
+    },
+  );
+
 =head1 DESCRIPTION
 
-Table object that inherits from L<DBIx::Class::ResultSource>
+View object that inherits from L<DBIx::Class::ResultSource>
+
+This class extends ResultSource to add basic view support.
+
+A view has a L</view_definition>, which contains a SQL query. The query can
+only have parameters if L</is_virtual> is set to true. It may contain JOINs,
+sub selects and any other SQL your database supports.
+
+View definition SQL is deployed to your database on
+L<DBIx::Class::Schema/deploy> unless you set L</is_virtual> to true.
+
+Deploying the view does B<not> translate it between different database
+syntaxes, so be careful what you write in your view SQL.
+
+Virtual views (L</is_virtual> true), are assumed to not
+exist in your database as a real view. The L</view_definition> in this
+case replaces the view name in a FROM clause in a subselect.
+
+=head1 EXAMPLES
+
+Having created the MyApp::Schema::Year2000CDs schema as shown in the SYNOPSIS
+above, you can then:
+
+  $2000_cds = $schema->resultset('Year2000CDs')
+                     ->search()
+                     ->all();
+  $count    = $schema->resultset('Year2000CDs')
+                     ->search()
+                     ->count();
+
+If you modified the schema to include a placeholder
+
+  __PACKAGE__->result_source_instance->view_definition(
+      "SELECT cdid, artist, title FROM cd WHERE year = ?"
+  );
+
+and ensuring you have is_virtual set to true:
+
+  __PACKAGE__->result_source_instance->is_virtual(1);
+
+You could now say:
+
+  $2001_cds = $schema->resultset('Year2000CDs')
+                     ->search({}, { bind => [2001] })
+                     ->all();
+  $count    = $schema->resultset('Year2000CDs')
+                     ->search({}, { bind => [2001] })
+                     ->count();
+
+=head1 SQL EXAMPLES
+
+=over
+
+=item is_virtual set to false
+
+  $schema->resultset('Year2000CDs')->all();
+
+  SELECT cdid, artist, title FROM year2000cds me
+
+=item is_virtual set to true
+
+  $schema->resultset('Year2000CDs')->all();
+
+  SELECT cdid, artist, title FROM
+    (SELECT cdid, artist, title FROM cd WHERE year ='2000') me
+
+=back
 
 =head1 METHODS
 
+=head2 is_virtual
+
+  __PACKAGE__->result_source_instance->is_virtual(1);
+
+Set to true for a virtual view, false or unset for a real
+database-based view.
+
+=head2 view_definition
+
+  __PACKAGE__->result_source_instance->view_definition(
+      "SELECT cdid, artist, title FROM cd WHERE year ='2000'"
+      );
+
+An SQL query for your view. Will not be translated across database
+syntaxes.
+
+=head2 deploy_depends_on
+
+  __PACKAGE__->result_source_instance->deploy_depends_on(
+      ["MyApp::Schema::Result::Year","MyApp::Schema::Result::CD"]
+      );
+
+Specify the views (and only the views) that this view depends on.
+Pass this an array reference of fully qualified result classes.
+
+=head1 OVERRIDDEN METHODS
+
 =head2 from
 
 Returns the FROM entry for the table (i.e. the view name)
+or the SQL as a subselect if this is a virtual view.
 
 =cut
 
-sub from { shift->name; }
+sub from {
+    my $self = shift;
+    return \"(${\$self->view_definition})" if $self->is_virtual;
+    return $self->name;
+}
 
-1;
+=head1 OTHER METHODS
 
-=head1 AUTHORS
+=head2 new
 
-Matt S. Trout <mst@shadowcatsystems.co.uk>
+The constructor.
 
-With Contributions from:
+=cut
+
+sub new {
+    my ( $self, @args ) = @_;
+    my $new = $self->next::method(@args);
+    $new->{deploy_depends_on} =
+      { map { $_ => 1 }
+          @{ $new->{deploy_depends_on} || [] } }
+      unless ref $new->{deploy_depends_on} eq 'HASH';
+    return $new;
+}
+
+1;
+
+=head1 AUTHORS
 
-Guillermo Roditi E<lt>groditi@cpan.orgE<gt>
+See L<DBIx::Class/CONTRIBUTORS>.
 
 =head1 LICENSE