README.md in json-serializer-0.0.2 vs README.md in json-serializer-0.0.3

@@ -1,6 +1,195 @@
 json-serializer
 ===============
 
-`ActiveModel::Serializers` outside Rails.
+Customizes JSON output through serializer objects.
 
-Not ready.
+A minimal implementation of [active_model_serializers][active_model_serializers] gem.
+
+Installation
+------------
+
+```
+gem install json-serializer
+```
+
+Usage
+-----
+
+### Basics
+
+Here's a simple example:
+
+```ruby
+require "json_serializer"
+
+class UserSerializer < JsonSerializer
+  attribute :id
+  attribute :first_name
+  attribute :last_name
+end
+```
+
+In this case, we defined a new serializer class and specified the attributes
+we would like to include in the serialized form.
+
+```ruby
+user = User.create(first_name: "Sonny", last_name: "Moore", admin: true)
+
+UserSerializer.new(user).to_json
+# => "{\"id\":1,\"first_name\":\"Sonny\",\"last_name\":\"Moore\"}"
+```
+
+You can add a root to the outputted json through the `:root` option:
+
+```ruby
+user = User.create(first_name: "Sonny", last_name: "Moore", admin: true)
+
+UserSerializer.new(user).to_json(root: :user)
+# => "{\"user\":{\"id\":1,\"first_name\":\"Sonny\",\"last_name\":\"Moore\"}}"
+```
+
+### Arrays
+
+A serializer can be used for objects contained in an array:
+
+```ruby
+require "json_serializer"
+
+class PostSerializer < JsonSerializer
+  attribute :id
+  attribute :title
+  attribute :body
+end
+
+posts = []
+posts << Post.create(title: "Post 1", body: "Hello!")
+posts << Post.create(title: "Post 2", body: "Goodbye!")
+
+PostSerializer.new(posts).to_json
+```
+
+Given the example above, it will return a json output like:
+
+```json
+[
+  { "id": 1, "title": "Post 1", "body": "Hello!" },
+  { "id": 2, "title": "Post 2", "body": "Goodbye!" }
+]
+```
+
+### Attributes
+
+By default, before looking up the attribute on the object, it checks the presence
+of a method with the name of the attribute. This allow serializes to include
+properties in addition to the object attributes or customize the result of a
+specified attribute. You can access the object being serialized with the +object+
+method.
+
+```ruby
+require "json_serializer"
+
+class UserSerializer < JsonSerializer
+  attribute :id
+  attribute :first_name
+  attribute :last_name
+  attribute :full_name
+
+  def full_name
+    object.first_name + " " + object.last_name
+  end
+end
+
+user = User.create(first_name: "Sonny", last_name: "Moore")
+
+UserSerializer.new(user).to_json
+# => "{\"id\":1,\"first_name\":\"Sonny\",\"last_name\":\"Moore\",\"full_name\":\"Sonny Moore\"}"
+```
+
+If you would like direct, low-level control of attribute serialization, you can
+completely override the attributes method to return the hash you need:
+
+```ruby
+require "json_serializer"
+
+class UserSerializer < JsonSerializer
+  attribute :id
+  attribute :first_name
+  attribute :last_name
+
+  attr :scope
+
+  def initialize(object, scope)
+    super(object)
+    @scope = scope
+  end
+
+  def attributes
+    hash = super
+    hash.merge!(admin: object.admin) if scope.admin?
+    hash
+  end
+end
+```
+
+### Attributes with Custom Serializer
+
+You can specify a serializer class for a defined attribute. This is very useful
+for serializing each element of an association.
+
+```ruby
+require "json_serializer"
+
+class UserSerializer < JsonSerializer
+  attribute :id
+  attribute :username
+end
+
+class PostSerializer < JsonSerializer
+  attribute :id
+  attribute :title
+  attribute :user, :UserSerializer
+  attribute :comments, :CommentSerializer
+end
+
+class CommentSerializer < JsonSerializer
+  attribute :id
+  attribute :content
+  attribute :user, :UserSerializer
+end
+
+admin = User.create(username: "admin", admin: true)
+user  = User.create(username: "user")
+
+post = Post.create(title: "Hello!", user: admin)
+post.comments << Comment.create(content: "First comment", user: user)
+
+PostSerializer.new(post).to_json
+```
+
+The example above returns the following json output:
+
+```json
+{
+  "id": 1,
+  "title": "Hello!",
+  "user":
+    {
+      "id": 1,
+      "username": "admin"
+    },
+  "comments":
+    [
+      {
+        "id": 1,
+        "content": "First comment",
+        "user":
+          {
+            "id": 2,
+            "username": "user"
+          }
+      }
+    ]
+}
+```
+
+[active_model_serializers]: https://github.com/rails-api/active_model_serializers