Fix Json related documentation for render and the AR serializer. Closes #9814. Closes #9833. [chuyeow]

git-svn-id: http://svn-commit.rubyonrails.org/rails/trunk@7905 5ecf4fe2-1ee6-0310-87b1-e25e094e27de

1 files changed, 53 insertions, 0 deletions

diff --git a/activerecord/lib/active_record/serializers/json_serializer.rb b/activerecord/lib/active_record/serializers/json_serializer.rb
index 8b1b8299f8..cf44309de7 100644
--- a/activerecord/lib/active_record/serializers/json_serializer.rb
+++ b/activerecord/lib/active_record/serializers/json_serializer.rb
@@ -1,5 +1,58 @@
 module ActiveRecord #:nodoc:
   module Serialization
+    # Returns a JSON string representing the model. Some configuration is
+    # available through +options+.
+    #
+    # Without any +options+, the returned JSON string will include all
+    # the model's attributes. For example:
+    #
+    #   konata = User.find(1)
+    #   konata.to_json
+    #
+    #   {"id": 1, "name": "Konata Izumi", "age": 16,
+    #    "created_at": "2006/08/01", "awesome": true}
+    #
+    # The :only and :except options can be used to limit the attributes
+    # included, and work similar to the #attributes method. For example:
+    #
+    #   konata.to_json(:only => [ :id, :name ])
+    #
+    #   {"id": 1, "name": "Konata Izumi"}
+    #
+    #   konata.to_json(:except => [ :id, :created_at, :age ])
+    #
+    #   {"name": "Konata Izumi", "awesome": true}
+    #
+    # To include any methods on the model, use :methods.
+    #
+    #   konata.to_json(:methods => :permalink)
+    #
+    #   {"id": 1, "name": "Konata Izumi", "age": 16,
+    #    "created_at": "2006/08/01", "awesome": true,
+    #    "permalink": "1-konata-izumi"}
+    #
+    # To include associations, use :include.
+    #
+    #   konata.to_json(:include => :posts)
+    #
+    #   {"id": 1, "name": "Konata Izumi", "age": 16,
+    #    "created_at": "2006/08/01", "awesome": true,
+    #    "posts": [{"id": 1, "author_id": 1, "title": "Welcome to the weblog"},
+    #              {"id": 2, author_id: 1, "title": "So I was thinking"}]}
+    #
+    # 2nd level and higher order associations work as well:
+    #
+    #   konata.to_json(:include => { :posts => {
+    #                                  :include => { :comments => {
+    #                                                :only => :body } },
+    #                                  :only => :title } })
+    #
+    #   {"id": 1, "name": "Konata Izumi", "age": 16,
+    #    "created_at": "2006/08/01", "awesome": true,
+    #    "posts": [{"comments": [{"body": "1st post!"}, {"body": "Second!"}],
+    #               "title": "Welcome to the weblog"},
+    #              {"comments": [{"body": "Don't think too hard"}],
+    #               "title": "So I was thinking"}]}
     def to_json(options = {})
       JsonSerializer.new(self, options).to_s
     end