In the end I think the pain of implementing this seamlessly was not
worth the gain provided.
The intention was that it would allow plain ruby objects that might not
live in your main application to be subclassed and have persistence
mixed in. But I've decided that the benefit of doing that is not worth
the amount of complexity that the implementation introduced.
I think it's going to be too much pain to try to transition the
:active_record load hook from executing against Base to executing
against Model.
For example, after Model is included in Base, and modules included in
Model will no longer get added to the ancestors of Base.
So plugins which wish to be compatible with both Model and Base should
use the :active_record_model load hook which executes *before* Base gets
loaded.
In general, ActiveRecord::Model is an advanced feature at the moment and
probably most people will continue to inherit from ActiveRecord::Base
for the time being.
Selecting which key extensions to include in active_support/rails
made apparent the systematic usage of Object#in? in the code base.
After some discussion in
5ea6b0df9a
we decided to remove it and use plain Ruby, which seems enough
for this particular idiom.
In this commit the refactor has been made case by case. Sometimes
include? is the natural alternative, others a simple || is the
way you actually spell the condition in your head, others a case
statement seems more appropriate. I have chosen the one I liked
the most in each case.
Moved logic from class_of_active_record_descendant(class) to the
base_class method. This method was confusing because it required
an argument, but that argument was 'self'.
Moved base_class tests to inheritance_test.rb and added some test
coverage for some untested cases.
The problem: We need to be able to specify configuration in a way that
can be inherited to models that include ActiveRecord::Model. So it is
no longer sufficient to put 'top level' config on ActiveRecord::Base,
but we do want configuration specified on ActiveRecord::Base and
descendants to continue to work.
So we need something like class_attribute that can be defined on a
module but that is inherited when ActiveRecord::Model is included.
The solution: added ActiveModel::Configuration module which provides a
config_attribute macro. It's a bit specific hence I am not putting this
in Active Support or making it a 'public API' at present.
