Merge pull request #1310 from maurogeorge/patch-12

RFC: Primary namespace: ActiveModel::Serializer, ActiveModel::Serializers, vs. ActiveModelSerializers

Author: bf4

docs/rfcs/0000-namespace.md

@@ -0,0 +1,106 @@
+- Start Date: (2015-10-29)
+- RFC PR: https://github.com/rails-api/active_model_serializers/pull/1310
+- ActiveModelSerializers Issue: https://github.com/rails-api/active_model_serializers/issues/1298
+
+# Summary
+
+Provide a consistent API for the user of the AMS.
+
+# Motivation
+
+The actual public API is defined under `ActiveModelSerializers`,
+`ActiveModel::Serializer` and `ActiveModel`.
+
+At the `ActiveModel::Serializer` we have:
+
+- `ActiveModel::Serializer.config`
+- `ActiveModel::Serializer`
+
+At the `ActiveModelSerializers` we have:
+
+- `ActiveModelSerializers::Model`
+- `ActiveModelSerializers.logger`
+
+At `ActiveModel` we have:
+
+- `ActiveModel::SerializableResource`
+
+The idea here is to provide a single namespace `ActiveModelSerializers` to the user.
+Following the same idea we have on other gems like
+[Devise](https://github.com/plataformatec/devise/blob/e9c82472ffe7c43a448945f77e034a0e47dde0bb/lib/devise.rb),
+[Refile](https://github.com/refile/refile/blob/6b24c293d044862dafbf1bfa4606672a64903aa2/lib/refile.rb) and
+[Active Job](https://github.com/rails/rails/blob/30bacc26f8f258b39e12f63fe52389a968d9c1ea/activejob/lib/active_job.rb)
+for example.
+
+This way we are clarifing the boundaries of
+[ActiveModelSerializers and Rails](https://github.com/rails-api/active_model_serializers/blob/master/CHANGELOG.md#prehistory)
+and make clear that the `ActiveModel::Serializer` class is no longer the primary
+behavior of the ActiveModelSerializers.
+
+# Detailed design
+
+## New classes and modules organization
+
+Since this will be a big change we can do this on baby steps, read small pull requests. A
+possible approach is:
+
+- All new code will be in `lib/active_model_serializers/` using
+  the module namespace `ActiveModelSerializers`.
+- Move all content under `ActiveModel::Serializer` to be under
+  `ActiveModelSerializers`, the adapter is on this steps;
+- Move all content under `ActiveModel` to be under `ActiveModelSerializers`,
+  the `SerializableResource` is on this step;
+- Change all public API that doesn't make sense, keeping in mind only to keep
+  this in the same namespace
+- Update the README;
+- Update the docs;
+
+The following table represents the current and the desired classes and modules
+at the first moment.
+
+| Current                                                | Desired                                          | Notes              |
+|--------------------------------------------------------|--------------------------------------------------|--------------------|
+| `ActiveModelSerializers` and `ActiveModel::Serializer` | `ActiveModelSerializers`                         | The main namespace |
+| `ActiveModelSerializers.logger`                        | `ActiveModelSerializers.logger`                  ||
+| `ActiveModelSerializers::Model`                        | `ActiveModelSerializers::Model`                  ||
+| `ActiveModel::SerializableResource`                    | `ActiveModelSerializers::SerializableResource`   ||
+| `ActiveModel::Serializer`                              | `ActiveModelSerializers::Serializer`             | The name can be discussed in a future pull request. For example, we can rename this to `Resource` [following this idea](https://github.com/rails-api/active_model_serializers/pull/1301/files#r42963185) more info about naming in the next section|
+| `ActiveModel::Serializer.config`                       | `ActiveModelSerializers.config`                ||
+
+## Renaming of class and modules
+
+When moving some content to the new namespace we can find some names that does
+not make much sense like `ActiveModelSerializers::Serializer::Adapter::JsonApi`.
+Discussion of renaming existing classes / modules and JsonApi objects will
+happen in separate pull requests, and issues, and in the google doc
+https://docs.google.com/document/d/1rcrJr0sVcazY2Opd_6Kmv1iIwuHbI84s1P_NzFn-05c/edit?usp=sharing
+
+Some of names already have a definition.
+
+- Adapters get their own namespace under ActiveModelSerializers. E.g
+  `ActiveModelSerializers::Adapter`
+- Serializers get their own namespace under ActiveModelSerializers. E.g
+  `ActiveModelSerializers::Serializer`
+
+## Keeping compatibility
+
+All moved classes or modules be aliased to their old name and location with
+deprecation warnings, such as
+[was done for CollectionSerializer](https://github.com/rails-api/active_model_serializers/pull/1251).
+
+# Drawbacks
+
+This will be a breaking change, so all users serializers will be broken after a
+major bump.
+All pull requests will need to rebase since the architeture will change a lot.
+
+# Alternatives
+
+We can keep the way it is, and keep in mind to not add another namespace as a
+public API.
+
+# Unresolved questions
+
+What is the better class name to be used to the class that will be inherited at
+the creation of a serializer. This can be discussed in other RFC or directly via
+pull request.