CacheableFlash

¶ ↑

Note: This fork (github.com/pboling/cacheable-flash/tree/master) of cacheable-flash aims to be a drop-in replacement for the original cacheable-flash (by Pivotal) but uses JQuery instead of Prototype, and merged several of the forks of the project to collect the best features and improvements.

Installation¶ ↑

ruby script/plugin install git://github.com/pboling/cacheable-flash.git

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.

Mailing List¶ ↑

groups.google.com/group/PivotalLabsOpenSource

Pivotal Tracker Bug/Feature Tracker¶ ↑

www.pivotaltracker.com/projects/10610

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 © 2007-2010 Pivotal Labs. This software is licensed under the MIT License.