use base qw/DBIx::Class::Core DBIx::Class::DB/;
use Carp::Clan qw/^DBIx::Class/;
-eval {
- require Class::Trigger;
- require DBIx::ContextualFetch;
-};
-croak "Class::Trigger and DBIx::ContextualFetch is required for CDBICompat" if $@;
+# Modules CDBICompat needs that DBIx::Class does not.
+my @Extra_Modules = qw(
+ Class::Trigger
+ DBIx::ContextualFetch
+ Clone
+);
+
+my @didnt_load;
+for my $module (@Extra_Modules) {
+ push @didnt_load, $module unless eval qq{require $module};
+}
+croak("@{[ join ', ', @didnt_load ]} are missing and are required for CDBICompat")
+ if @didnt_load;
+
__PACKAGE__->load_own_components(qw/
Constraints
=head1 SYNOPSIS
- use base qw/DBIx::Class/;
- __PACKAGE__->load_components(qw/CDBICompat Core DB/);
+ package My::CDBI;
+ use base qw/DBIx::Class::CDBICompat/;
+
+ ...continue as Class::DBI...
=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.
+and some common plugins 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:
+This is not a wrapper or subclass of DBIx::Class but rather a series of plugins. The result being that even though you're using the Class::DBI emulation layer you are still getting DBIx::Class objects. You can use all DBIx::Class features and methods via CDBICompat. This allows you to take advantage of DBIx::Class features without having to rewrite your CDBI code.
- __PACKAGE__->load_own_components(qw/CDBICompat/);
-this will automatically load the features included in My::DB::CDBICompat,
-provided it looks something like this:
+=head2 Plugins
- package My::DB::CDBICompat;
- __PACKAGE__->load_components(qw/
- CDBICompat::ColumnGroups
- CDBICompat::Retrieve
- CDBICompat::HasA
- CDBICompat::HasMany
- CDBICompat::MightHave
- /);
+CDBICompat is good enough that many CDBI plugins will work with CDBICompat, but many of the plugin features are better done with DBIx::Class methods.
-=head1 COMPONENTS
-
-=over 4
+=head3 Class::DBI::AbstractSearch
-=item AccessorMapping
+C<search_where()> is fully emulated using DBIC's search. Aside from emulation there's no reason to use C<search_where()>.
-=item AbstractSearch
+=head3 Class::DBI::Plugin::NoCache
-Compatibility with Class::DBI::AbstractSearch.
+C<nocache> is fully emulated.
-=item AttributeAPI
+=head3 Class::DBI::Sweet
-=item AutoUpdate
+The features of CDBI::Sweet are better done using DBIC methods which are almost exactly the same. It even uses L<Data::Page>.
-Allows you to turn on automatic updates for column values.
+=head3 Class::DBI::Plugin::DeepAbstractSearch
-=item ColumnCase
+This plugin will work, but it is more efficiently done using DBIC's native search facilities. The major difference is that DBIC will not infer the join for you, you have to tell it the join tables.
-=item ColumnGroups
-=item Constraints
+=head2 Choosing Features
-=item Constructor
-
-=item DestroyWarning
-
-=item GetSet
+In fact, this class is just a recipe 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:
-=item HasA
+ package My::DB;
+ __PACKAGE__->load_own_components(qw/CDBICompat/);
-=item HasMany
+this will automatically load the features included in My::DB::CDBICompat,
+provided it looks something like this:
-=item ImaDBI
+ package My::DB::CDBICompat;
+ __PACKAGE__->load_components(qw/
+ CDBICompat::ColumnGroups
+ CDBICompat::Retrieve
+ CDBICompat::HasA
+ CDBICompat::HasMany
+ CDBICompat::MightHave
+ /);
-=item LazyLoading
-=item LiveObjectIndex
+=head1 LIMITATIONS
-The live object index tries to ensure there is only one version of a object
-in the perl interpreter.
+=head2 Unimplemented
-=item MightHave
+The following methods and classes are not emulated, maybe in the future.
-=item ObjIndexStubs
+=over 4
-=item ReadOnly
+=item Class::DBI::Query
-=item Retrieve
+Deprecated in Class::DBI.
-=item Stringify
+=item Class::DBI::Column
-=item TempColumns
+Not documented in Class::DBI. CDBICompat's columns() returns a plain string, not an object.
-=item Triggers
+=item data_type()
-=item PassThrough
+Undocumented CDBI method.
=back
-=head1 LIMITATIONS
+=head2 Limited Support
-The following methods and classes are not emulated, maybe in the future.
+The following elements of Class::DBI have limited support.
=over 4
-=item Class::DBI::Query
+=item Class::DBI::Relationship
-Deprecated in Class::DBI.
+The semi-documented Class::DBI::Relationship objects returned by C<meta_info($type, $col)> are mostly emulated except for their C<args> method.
-=item Class::DBI::Column
+=item Relationships
-Not documented in Class::DBI. CDBICompat's columns() returns a plain string, not an object.
+Relationships between tables (has_a, has_many...) must be declared 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:
-=item data_type()
+ package Foo;
+ use base qw(Class::DBI);
-Undocumented CDBI method.
+ Foo->table("foo");
+ Foo->columns( All => qw(this that bar) );
-=item meta_info()
+ 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" );
-Undocumented CDBI method.
=back
projects / dbsrgits/DBIx-Class.git / blobdiff