CacheableFlash

========

Installation

ruby script/plugin install svn://rubyforge.org/var/svn/pivotalrb/cacheable_flash/trunk

Description

This plugin enables greater levels of page caching by rendering flash messages from a cookie using JavaScript, instead of in your Rails view template. Flash contents are converted to JSON and placed in a cookie by an after_filter in a controller.

Usage

To use, include the CacheableFlash module in your controller. It’s all or none on the actions in your controller, so you can’t mix JS and HTML display of your flash message in a controller. No other modifications to the controller are needed. You will need to add divs and some javascript to your view or layout templates to render the flash in the browser.

Note that the cookie holding the flash messages is removed as the page is displayed, so a refresh will clear the flash message (just as happens normally).

Example Controller

class MyController < ActionController::Base

  include CacheableFlash
  # ...

end

Example Template Markup

  <div id="error_div_id" class="flash flash_error"></div>
  <div id="notice_div_id" class="flash flash_notice"></div>
  <script type="text/javascript">
    Flash.transferFromCookies();
    Flash.writeDataTo('error', $('error_div_id'));
    Flash.writeDataTo('notice', $('notice_div_id'));
  </script>

Testing

You can test your flash cookies by making assertions on the json of the "flash" cookie. Cacheable Flash provides test helpers which includes the flash_cookie method.

Test::Unit Example

  require "cacheable_flash/test_helpers"

  class TestController < ActionController::Base
    def index
      flash["notice"] = "In index"
    end
  end

  class ControllerTest < Test::Unit::TestCase
    include CacheableFlash::TestHelpers

    def setup
      @controller = TestController.new
      @request = ActionController::TestRequest.new
      @response = ActionController::TestResponse.new
    end

    def test_cacheable_flash_action
      get :index
      asset_equal "In index", flash_cookie["notice"]
    end
  end

Rspec Example

  require "cacheable_flash/test_helpers"

  class TestController < ActionController::Base
    def index
      flash["notice"] = "In index"
    end
  end

  describe TestController, "#index" do
    include CacheableFlash::TestHelpers

    it "writes to the flash cookie" do
      get :index
      flash_cookie["notice"].should == "In index"
    end
  end

Copyright

MIT License Copyright © 2007 Pivotal Labs

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.