Better handling of UUID setup

README.md

@@ -277,42 +277,34 @@ You'll need to create the migration file with the argument `--uuid resource_owne
 mix ex_oauth2_provider.install --uuid resource_owners
 ```
 
-### 2. If all structs should use `:uuid`
-
-If you don't have auto-incrementing integers as primary keys in your database you can set up `ExOauth2Provider` to handle all primary keys as `:uuid` by doing the following.
-
-You should have a schema macro similar to this (the `@primary_key` and `@foreign_key_type` needs to be defined):
+And set the config to use `:binary_id` for `belongs_to` fields:
 
 ```elixir
-defmodule MyApp.Schema do
-  @moduledoc false
-  defmacro __using__(_) do
-    quote do
-      use Ecto.Schema
-      @primary_key {:id, :binary_id, autogenerate: true}
-      @foreign_key_type :binary_id
-    end
-  end
-end
+config :ex_oauth2_provider, ExOauth2Provider,
+  resource_owner: {Dummy.User, :binary_id}
 ```
 
-Update the `:ex_oauth2_provider` config in `config/config.exs` to use the schema macro:
+### 2. If all structs should use `:uuid`
+
+If you don't have auto-incrementing integers as primary keys in your database you can set up `ExOauth2Provider` to handle all primary keys as `:uuid` by doing the following.
+
+Update the `:ex_oauth2_provider` config in `config/config.exs` to use the the [UUID schema](lib/ex_oauth2_provider/schemas/uuid.ex) macro:
 
 ```elixir
 config :ex_oauth2_provider, ExOauth2Provider,
-  # ...
-  app_schema: MyApp.Schema
+  resource_owner: {Dummy.User, :binary_id},
+  app_schema: ExOauth2Provider.Schema.UUID
 ```
 
-And generate a migration file that uses `:uuid` type for all tables:
+And generate a migration file that uses `:uuid` for all tables:
 
 ```bash
 mix ex_oauth2_provider.install --uuid all
 ```
 
 ### 3. If you need something different than `:uuid`
 
-It's also possible to use a completely different setup by adding a custom schema macro like in the section above. You'll have to update the migration file accordingly.
+It's also possible to use a completely different setup by adding a custom schema macro, however you'll need to ensure that the schema file is compiled before this library and that you've updated the migration file accordingly.
 
 ## Acknowledgement
 

config/test.exs

@@ -10,8 +10,12 @@ config :ex_oauth2_provider, ExOauth2Provider,
   revoke_refresh_token_on_use: true,
   grant_flows: ~w(authorization_code client_credentials)
 
+if System.get_env("UUID") do
+  config :ex_oauth2_provider, ExOauth2Provider, resource_owner: {Dummy.User, :binary_id}
+end
+
 if System.get_env("UUID") == "all" do
-  config :ex_oauth2_provider, ExOauth2Provider, app_schema: Dummy.UUIDSchema
+  config :ex_oauth2_provider, ExOauth2Provider, app_schema: ExOauth2Provider.Schema.UUID
 end
 
 config :ex_oauth2_provider, ecto_repos: [ExOauth2Provider.Test.Repo]

lib/ex_oauth2_provider/config.ex

@@ -6,9 +6,11 @@ defmodule ExOauth2Provider.Config do
   end
 
   @doc false
-  @spec resource_owner_struct() :: atom
-  def resource_owner_struct do
-    Keyword.get(config(), :resource_owner)
+  @spec resource_owner_struct(atom) :: atom
+  def resource_owner_struct(type) do
+    config()
+    |> Keyword.get(:resource_owner)
+    |> parse_owner_struct(type)
   end
 
   @doc false
@@ -18,9 +20,13 @@ defmodule ExOauth2Provider.Config do
   end
 
   @doc false
-  @spec application_owner_struct() :: atom
-  def application_owner_struct do
-    Keyword.get(config(), :application_owner, resource_owner_struct())
+  @spec application_owner_struct(atom) :: atom
+  def application_owner_struct(type) do
+    resource_owner = Keyword.get(config(), :resource_owner)
+
+    config()
+    |> Keyword.get(:application_owner, resource_owner)
+    |> parse_owner_struct(type)
   end
 
   # Define default access token scopes for your provider
@@ -138,4 +144,9 @@ defmodule ExOauth2Provider.Config do
   defp grant_type_can_be_used?(grant_flows, grant_type) do
     Enum.member?(grant_flows, grant_type)
   end
+
+  defp parse_owner_struct({_module, foreign_key_type}, :foreign_key_type), do: foreign_key_type
+  defp parse_owner_struct({module, _foreign_key_type}, :module), do: module
+  defp parse_owner_struct(module, :module), do: module
+  defp parse_owner_struct(_module, :foreign_key_type), do: :id
 end

lib/ex_oauth2_provider/oauth_access_grants/oauth_access_grant.ex

@@ -3,13 +3,10 @@ defmodule ExOauth2Provider.OauthAccessGrants.OauthAccessGrant do
 
   use ExOauth2Provider.Schema
   alias ExOauth2Provider.OauthApplications.OauthApplication
-  alias ExOauth2Provider.{Config, Utils}
-
-  @resource_owner_struct Config.resource_owner_struct()
-  @resource_owner_belongs_to_opts Utils.schema_belongs_to_opts(@resource_owner_struct)
+  alias ExOauth2Provider.Config
 
   schema "oauth_access_grants" do
-    belongs_to :resource_owner, @resource_owner_struct, @resource_owner_belongs_to_opts
+    belongs_to :resource_owner, Config.resource_owner_struct(:module), type: Config.resource_owner_struct(:foreign_key_type)
     belongs_to :application, OauthApplication
 
     field :token,        :string,     null: false

lib/ex_oauth2_provider/oauth_access_tokens/oauth_access_token.ex

@@ -3,14 +3,11 @@ defmodule ExOauth2Provider.OauthAccessTokens.OauthAccessToken do
 
   use ExOauth2Provider.Schema
   alias ExOauth2Provider.OauthApplications.OauthApplication
-  alias ExOauth2Provider.{Config, Utils}
-
-  @resource_owner_struct Config.resource_owner_struct()
-  @resource_owner_belongs_to_opts Utils.schema_belongs_to_opts(@resource_owner_struct)
+  alias ExOauth2Provider.Config
 
   schema "oauth_access_tokens" do
+    belongs_to :resource_owner, Config.resource_owner_struct(:module), type: Config.resource_owner_struct(:foreign_key_type)
     belongs_to :application, OauthApplication, on_replace: :nilify
-    belongs_to :resource_owner, @resource_owner_struct, @resource_owner_belongs_to_opts
 
     field :token,         :string, null: false
     field :refresh_token, :string

lib/ex_oauth2_provider/oauth_applications/oauth_application.ex

@@ -3,19 +3,17 @@ defmodule ExOauth2Provider.OauthApplications.OauthApplication do
 
   use ExOauth2Provider.Schema
   require Logger
-  alias ExOauth2Provider.{Config, Utils}
+  alias ExOauth2Provider.Config
 
   # For Phoenix integrations
   if Code.ensure_loaded?(Phoenix.Param) do
     @derive {Phoenix.Param, key: :uid}
   end
 
-  @owner_struct Config.application_owner_struct()
-  @owner_belongs_to_opts Utils.schema_belongs_to_opts(@owner_struct)
-  if is_nil(@owner_struct), do: Logger.error("You need to set a resource_owner or application_owner in your config and recompile ex_oauth2_provider!")
+  if is_nil(Config.application_owner_struct(:module)), do: Logger.error("You need to set a resource_owner or application_owner in your config and recompile ex_oauth2_provider!")
 
   schema "oauth_applications" do
-    belongs_to :owner, @owner_struct, @owner_belongs_to_opts
+    belongs_to :owner, Config.application_owner_struct(:module), type: Config.application_owner_struct(:foreign_key_type)
 
     field :name,         :string,     null: false
     field :uid,          :string,     null: false

lib/ex_oauth2_provider/schemas/uuid.ex

@@ -0,0 +1,13 @@
+defmodule ExOauth2Provider.Schema.UUID do
+  @moduledoc """
+  This module will permit autogenerated UUID.
+  """
+
+  defmacro __using__(_) do
+    quote do
+      use Ecto.Schema
+      @primary_key {:id, :binary_id, autogenerate: true}
+      @foreign_key_type :binary_id
+    end
+  end
+end

lib/ex_oauth2_provider/utils.ex

@@ -28,8 +28,4 @@ defmodule ExOauth2Provider.Utils do
   def schema_association(module, association) do
     module.__schema__(:association, association)
   end
-
-  @spec schema_belongs_to_opts(Ecto.Schema | nil) :: Keyword.t
-  def schema_belongs_to_opts(nil), do: []
-  def schema_belongs_to_opts(module), do: [type: module.__schema__(:type, :id)]
 end

test/support/dummy/models/user.ex

@@ -1,7 +1,7 @@
 defmodule Dummy.User do
   @moduledoc false
 
-  use Dummy.UUIDSchema
+  use Dummy.Schema
   import Ecto.Changeset
 
   schema "users" do

test/support/dummy/schema.ex

@@ -0,0 +1,14 @@
+defmodule Dummy.Schema do
+  @moduledoc """
+  This module will permit dynamic App.Schema load.
+  """
+  defmacro __using__(_) do
+    schema = if is_nil(System.get_env("UUID")),
+      do: Ecto.Schema,
+      else: ExOauth2Provider.Schema.UUID
+
+    quote do
+      use unquote(schema)
+    end
+  end
+end

test/support/fixture.ex

@@ -6,7 +6,7 @@ defmodule ExOauth2Provider.Test.Fixture do
   alias ExOauth2Provider.OauthAccessGrants
   alias ExOauth2Provider.Test.Repo
 
-  @resource_owner ExOauth2Provider.Config.resource_owner_struct()
+  @resource_owner ExOauth2Provider.Config.resource_owner_struct(:module)
 
   def fixture(:user, attrs \\ %{}) do
     {:ok, user} = %@resource_owner{}