Emulate $CDBI::Weaken_Not_Available and CDBI::Plugin::NoCache

[dbsrgits/DBIx-Class.git] / lib / DBIx / Class / CDBICompat.pm

diff --git a/lib/DBIx/Class/CDBICompat.pm b/lib/DBIx/Class/CDBICompat.pm
index c5e2634..49988c9 100644 (file)
--- a/lib/DBIx/Class/CDBICompat.pm
+++ b/lib/DBIx/Class/CDBICompat.pm
@@ -2,21 +2,139 @@ package DBIx::Class::CDBICompat;
 
 use strict;
 use warnings;
+use base qw/DBIx::Class::Core DBIx::Class::DB/;
+use Carp::Clan qw/^DBIx::Class/;
 
-use base qw/DBIx::Class::CDBICompat::Convenience
-            DBIx::Class::CDBICompat::Triggers
-            DBIx::Class::CDBICompat::GetSet
-            DBIx::Class::CDBICompat::AttributeAPI
-            DBIx::Class::CDBICompat::Stringify
-            DBIx::Class::CDBICompat::ObjIndexStubs
-            DBIx::Class::CDBICompat::DestroyWarning
-            DBIx::Class::CDBICompat::Constructor
-            DBIx::Class::CDBICompat::AccessorMapping
-            DBIx::Class::CDBICompat::ColumnCase
-            DBIx::Class::CDBICompat::HasA
-            DBIx::Class::CDBICompat::LazyLoading
-            DBIx::Class::CDBICompat::AutoUpdate
-            DBIx::Class::CDBICompat::ColumnGroups
-            DBIx::Class::CDBICompat::ImaDBI/;
+eval {
+  require Class::Trigger;
+  require DBIx::ContextualFetch;
+};
+croak "Class::Trigger and DBIx::ContextualFetch is required for CDBICompat" if $@;
 
+__PACKAGE__->load_own_components(qw/
+  Constraints
+  Triggers
+  ReadOnly
+  LiveObjectIndex
+  AttributeAPI
+  Stringify
+  DestroyWarning
+  Constructor
+  AccessorMapping
+  ColumnCase
+  Relationships
+  Copy
+  LazyLoading
+  AutoUpdate
+  TempColumns
+  GetSet
+  Retrieve
+  Pager
+  ColumnGroups
+  ColumnsAsHash
+  AbstractSearch
+  ImaDBI
+  Iterator
+/);
+
+            #DBIx::Class::ObjIndexStubs
 1;
+
+=head1 NAME
+
+DBIx::Class::CDBICompat - Class::DBI Compatibility layer.
+
+=head1 SYNOPSIS
+
+  use base qw/DBIx::Class/;
+  __PACKAGE__->load_components(qw/CDBICompat Core DB/);
+
+=head1 DESCRIPTION
+
+DBIx::Class features a fully featured compatibility layer with L<Class::DBI>
+and L<Class::DBI::AbstractSearch> to ease transition for existing CDBI users. 
+
+In fact, this class is just a receipe containing all the features emulated.
+If you like, you can choose which features to emulate by building your 
+own class and loading it like this:
+
+  __PACKAGE__->load_own_components(qw/CDBICompat/);
+
+this will automatically load the features included in My::DB::CDBICompat,
+provided it looks something like this:
+
+  package My::DB::CDBICompat;
+  __PACKAGE__->load_components(qw/
+    CDBICompat::ColumnGroups
+    CDBICompat::Retrieve
+    CDBICompat::HasA
+    CDBICompat::HasMany
+    CDBICompat::MightHave
+  /);
+
+
+=head1 LIMITATIONS
+
+=head2 Unimplemented
+
+The following methods and classes are not emulated, maybe in the future.
+
+=over 4
+
+=item Class::DBI::Query
+
+Deprecated in Class::DBI.
+
+=item Class::DBI::Column
+
+Not documented in Class::DBI.  CDBICompat's columns() returns a plain string, not an object.
+
+=item data_type()
+
+Undocumented CDBI method.
+
+=back
+
+=head2 Limited Support
+
+The following elements of Class::DBI have limited support.
+
+=over 4
+
+=item Class::DBI::Relationship
+
+The semi-documented Class::DBI::Relationship objects returned by C<meta_info($type, $col)> are mostly emulated except for their C<args> method.
+
+=item Relationships
+
+Relationships between tables (has_a, has_many...) must be delcared after all tables in the relationship have been declared.  Thus the usual CDBI idiom of declaring columns and relationships for each class together will not work.  They must instead be done like so:
+
+    package Foo;
+    use base qw(Class::DBI);
+    
+    Foo->table("foo");
+    Foo->columns( All => qw(this that bar) );
+
+    package Bar;
+    use base qw(Class::DBI);
+    
+    Bar->table("bar");
+    Bar->columns( All => qw(up down) );
+
+    # Now that Foo and Bar are declared it is safe to declare a
+    # relationship between them
+    Foo->has_a( bar => "Bar" );
+
+
+=back
+
+=head1 AUTHORS
+
+Matt S. Trout <mst@shadowcatsystems.co.uk>
+
+=head1 LICENSE
+
+You may distribute this code under the same terms as Perl itself.
+
+=cut
+