Ruby Quicktips

Rails’ include_root_in_json

When rendering JSON from your controllers (or when using to_json directly), Rails 3.1 and above won’t include the root element in the output:

post = Post.first
# => #<Post id: 1, title: "My first blogpost" ...

post.to_json
# => "{\"id\":1,\"title\":\"My first blogpost\", ...}"

To include the root element (post in this example), set ActiveRecord::Base.include_root_in_json to true:

# wrap_paramters.rb
if defined?(ActiveRecord)
  ActiveRecord::Base.include_root_in_json = true
end

Result:

post.to_json
# => "{\"post\":{\"id\":1,\"title\":\"My first blogpost\", ...}}"

In version of Rails < 3.1, including the root element is the default. You can disable it by adding ActiveRecord::Base.include_root_in_json = false to one of your files in config/initializers or in application.rb/environment.rb directly.

More info in the API docs on ActiveModel::Serializers::JSON.