Breaking change:
- Adapters now inherit Adapter::Base
- 'Adapter' is now a module, no longer a class
Why?
- using a class as a namespace that you also inherit from is complicated and circular at time i.e.
buggy (see https://github.com/rails-api/active_model_serializers/pull/1177)
- The class methods on Adapter aren't necessarily related to the instance methods, they're more
Adapter functions
- named `Base` because it's a Rails-ism
- It helps to isolate and highlight what the Adapter interface actually is
Changes:
- Introduce Adapter::get for use by Serializer.adapter
- Move Adapter-finding logic from Adapter::adapter_class into Adapter::get
Introduced interfaces:
- non-inherited methods
```ruby
ActiveModel::Serializer::Adapter.adapter_map # a Hash<adapter_name, adapter_class>
ActiveModel::Serializer::Adapter.adapters # an Array<adapter_name>
ActiveModel::Serializer::Adapter.register(name, klass) # adds an adapter to the adapter_map
ActiveModel::Serializer::Adapter.get(name_or_klass) # raises Argument error when adapter not found
```
- Automatically register adapters when subclassing
```ruby
def self.inherited(subclass)
ActiveModel::Serializer::Adapter.register(subclass.to_s.demodulize, subclass)
end
```
- Preserves subclass method `::adapter_class(adapter)`
```ruby
def self.adapter_class(adapter)
ActiveModel::Serializer::Adapter.get(adapter)
end
```
- Serializer.adapter now uses `Adapter.get(config.adapter)` rather than have duplicate logic
