Installation as gem
gem 'cacheable_flash' # added to your Gemfile $ bundle install
Without asset pipeline, or pre-Rails 3.1:
First copy the JS assets into your app:
rails generate cacheable_flash:install
So if you have config.assets.enabled = false in application.rb then in your layout:
Otherwise, in your layout, just source them like normal:
With asset pipeline (requires Rails 3.1)
//= require flash //= require js.
Please help document!
Usage as an around filter
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).
class MyController < ActionController::Base include CacheableFlash # ... end
Usage as a Rack middleware (requires Rails 3)
To use as a Rack Middleware, swap the Rails flash middleware with the Cacheable flash middleware. Use this method if you set flash messages inside a rescue_from block:
rescue_from CanCan::AccessDenied do |exception| redirect_to root_url, :alert => exception. end
In your application.rb:
# Swap the ActionDispatch::Flash middleware with the CacheableFlash one config.middleware.swap ActionDispatch::Flash, CacheableFlash::Middleware
Example Template Markup
The gem is susceptible to reflected XSS attack. Make sure no non-alphanumerical user-generated content is stored inside flash messages (html or plain text).
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.
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 assert_equal "In index", ["notice"] end end
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 ["notice"].should == "In index" end end
Contributing to cacheable-flash
Create your feature branch (`git checkout -b my-new-feature`)
Commit your changes (`git commit -am 'Added some feature'`)
Push to the branch (`git push origin my-new-feature`)
Make sure to add tests for it. This is important so I don't break it in a future version unintentionally.
Create new Pull Request
This library aims to adhere to Semantic Versioning 2.0.0. Violations of this scheme should be reported as bugs. Specifically, if a minor or patch version is released that breaks backward compatibility, a new version should be immediately released that restores compatibility. Breaking changes to the public API will only be introduced with new major versions.
As a result of this policy, you can (and should) specify a dependency on this gem using the Pessimistic Version Constraint with two digits of precision.
spec.add_dependency 'cacheable_flash', '~> 4.0'
Licensed under the MIT License. See LICENSE for further details.