Serialization Scopes

Define scopes for XML/JSON serialization of your ActiveRecord models.

In your models

Serialization Scopes extends ActiveRecord and provides a serialization_scope class method for defining custom scopes. Example:

# Column names: id, title, body, date, personal_notes, comments_count, author_id
class Article < ActiveRecord::Base
  has_many :comments

  serialization_scope :author, :except => [:comments_count]
  serialization_scope :reader, :only => [:title, :body, :date], :include => [:comments]
end

Scoping serialization output

Scopes can be applied as options to the usual #to_xml and #to_json methods. Examples:

Apply the default scope. This can be overridden in models via serialization_scope :default, ...:

Article.first.to_json
# => {"id":1,"title":"Hello","body":"World","date":"2010-01-01","personal_notes":"Author's notes","comments_count":3,"author_id":1}

Apply a custom scope:

Article.first.to_json(:scope => :author)
# => {"id":1,"title":"Hello","body":"World","date":"2010-01-01","personal_notes":"Author's notes","author_id":1}

Custom scopes can still be extended/overridden:

Article.first.to_json(:scope => :author, :only => [:title])
# => {"title":"Hello"}

In your controllers

Serialization Scopes comes with a responder which you can include to your own. Create your own responder:

# lib/my_responder.rb
class MyResponder < ActionController::Responder
  include SerializationScopes::Responder
end

And then you need to configure your application to use it:

# app/controllers/application_controller.rb
require "my_responder"

class ApplicationController < ActionController::Base
  self.responder = MyResponder
end

In your controllers, then simply define a protected serialization_scope method. It will be automatically applied as part of respond_with. Example:

# app/controllers/articles_controller.rb
class ArticlesController < ApplicationController
  respond_to :html, :xml, :json

  def show
    @article = Article.find params[:id]
    respond_with @article
  end

  protected

  	def serialization_scope
  	  @article && @article.author == current_user ? :author : :reader
  	end

end

License

(The MIT License)

Copyright (c) 2011 Dimitrij Denissenko

Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.