outside controller use tutorial

Author: Terminator3

docs/README.md

@@ -14,6 +14,7 @@ This is the documentation of AMS, it's focused on the **0.10.x version.**
 
 - [How to add root key](howto/add_root_key.md)
 - [How to add pagination links](howto/add_pagination_links.md)
+- [Using AMS Outside Of Controllers](howto/outside_controller_use.md)
 
 ## Getting Help
 

docs/howto/outside_controller_use.md

@@ -0,0 +1,42 @@
+## Using AMS Outside Of A Controller
+
+### Serializing a resource 
+
+In AMS versions 0.10 or later, serializing resources outside of the controller context is fairly simple:
+
+```ruby
+# Create our resource
+post = Post.create(title: "Sample post", body: "I love Active Model Serializers!")
+
+# Optional options parameters
+options = {}
+
+# Create a serializable resource instance
+serializable_resource = ActiveModel::SerializableResource.new(post, options)
+
+# Convert your resource into json
+model_json = serializable_resource.as_json
+``` 
+
+### Retrieving a Resource's Active Model Serializer
+
+If you want to retrieve a serializer for a specific resource, you can do the following:
+
+```ruby
+# Create our resource 
+post = Post.create(title: "Another Example", body: "So much fun.")
+
+# Optional options parameters
+options = {}
+
+# Retrieve the default serializer for posts
+serializer = ActiveModel::Serializer.serializer_for(post, options)
+```
+
+You could also retrieve the serializer via: 
+
+```ruby
+ActiveModel::SerializableResource.new(post, options).serializer 
+```
+
+Both approaches will return an instance, if any, of the resource's serializer.