Extract advanced features

Author: mylanconnolly

usage-rules.md

@@ -10,64 +10,6 @@ SPDX-License-Identifier: MIT
 
 AshPostgres is the PostgreSQL data layer for Ash Framework. It's the most fully-featured Ash data layer and should be your default choice unless you have specific requirements for another data layer. Any PostgreSQL version higher than 13 is fully supported.
 
-## Advanced Features
-
-### Manual Relationships
-
-For complex relationships that can't be expressed with standard relationship types:
-
-```elixir
-defmodule MyApp.Post.Relationships.HighlyRatedComments do
-  use Ash.Resource.ManualRelationship
-  use AshPostgres.ManualRelationship
-
-  def load(posts, _opts, context) do
-    post_ids = Enum.map(posts, & &1.id)
-
-    {:ok,
-     MyApp.Comment
-     |> Ash.Query.filter(post_id in ^post_ids)
-     |> Ash.Query.filter(rating > 4)
-     |> MyApp.read!()
-     |> Enum.group_by(& &1.post_id)}
-  end
-
-  def ash_postgres_join(query, _opts, current_binding, as_binding, :inner, destination_query) do
-    {:ok,
-     Ecto.Query.from(_ in query,
-       join: dest in ^destination_query,
-       as: ^as_binding,
-       on: dest.post_id == as(^current_binding).id,
-       on: dest.rating > 4
-     )}
-  end
-
-  # Other required callbacks...
-end
-
-# In your resource:
-relationships do
-  has_many :highly_rated_comments, MyApp.Comment do
-    manual MyApp.Post.Relationships.HighlyRatedComments
-  end
-end
-```
-
-### Using Multiple Repos (Read Replicas)
-
-Configure different repos for reads vs mutations:
-
-```elixir
-postgres do
-  repo fn resource, type ->
-    case type do
-      :read -> MyApp.ReadReplicaRepo
-      :mutate -> MyApp.WriteRepo
-    end
-  end
-end
-```
-
 ## Best Practices
 
 1. **Organize migrations**: Run `mix ash.codegen` after each meaningful set of resource changes with a descriptive name:

usage-rules/advanced_features.md

@@ -0,0 +1,63 @@
+<!--
+SPDX-FileCopyrightText: 2020 Zach Daniel
+
+SPDX-License-Identifier: MIT
+-->
+
+# Advanced Features
+
+## Manual Relationships
+
+For complex relationships that can't be expressed with standard relationship types:
+
+```elixir
+defmodule MyApp.Post.Relationships.HighlyRatedComments do
+  use Ash.Resource.ManualRelationship
+  use AshPostgres.ManualRelationship
+
+  def load(posts, _opts, context) do
+    post_ids = Enum.map(posts, & &1.id)
+
+    {:ok,
+     MyApp.Comment
+     |> Ash.Query.filter(post_id in ^post_ids)
+     |> Ash.Query.filter(rating > 4)
+     |> MyApp.read!()
+     |> Enum.group_by(& &1.post_id)}
+  end
+
+  def ash_postgres_join(query, _opts, current_binding, as_binding, :inner, destination_query) do
+    {:ok,
+     Ecto.Query.from(_ in query,
+       join: dest in ^destination_query,
+       as: ^as_binding,
+       on: dest.post_id == as(^current_binding).id,
+       on: dest.rating > 4
+     )}
+  end
+
+  # Other required callbacks...
+end
+
+# In your resource:
+relationships do
+  has_many :highly_rated_comments, MyApp.Comment do
+    manual MyApp.Post.Relationships.HighlyRatedComments
+  end
+end
+```
+
+## Using Multiple Repos (Read Replicas)
+
+Configure different repos for reads vs mutations:
+
+```elixir
+postgres do
+  repo fn resource, type ->
+    case type do
+      :read -> MyApp.ReadReplicaRepo
+      :mutate -> MyApp.WriteRepo
+    end
+  end
+end
+```