README.md

Flipper::UI

UI for the Flipper gem.

Screenshots

Viewing list of features:

Viewing an individual feature:

Installation

Add this line to your application's Gemfile:

gem 'flipper-ui'

And then execute:

$ bundle

Or install it yourself as:

$ gem install flipper-ui

Usage

Rails

Given that you've already initialized Flipper as per the flipper readme, you can mount Flipper::UI to a route of your choice:

# config/routes.rb
YourRailsApp::Application.routes.draw do
  mount Flipper::UI.app(Flipper) => '/flipper'
end

If you'd like to lazy load flipper, you can pass a block instead:

# config/routes.rb
YourRailsApp::Application.routes.draw do
  flipper_block = lambda {
    # some flipper initialization here, for example:
    # YourRailsApp.flipper
  }
  mount Flipper::UI.app(flipper_block) => '/flipper'
end

Security

You almost certainly want to limit access when using Flipper::UI in production.

Basic Authentication via Rack

The Flipper::UI.app method yields a builder instance prior to any predefined middleware. You can insert the Rack::Auth::Basic middleware, that'll prompt for a username and password when visiting the defined (i.e., /flipper) route.

# config/routes.rb

flipper_app = Flipper::UI.app(Flipper.instance) do |builder|
  builder.use Rack::Auth::Basic do |username, password|
    # Verify credentials
  end
end
mount flipper_app, at: '/flipper'

Route Constraints

It is possible to use routes constraints to limit access to routes:

# config/routes.rb

flipper_constraint = lambda { |request| request.remote_ip == '127.0.0.1' }
constraints flipper_constraint do
  mount Flipper::UI.app(flipper) => '/flipper'
end

Another example is to use the current_user when using a gem-based authentication system (i.e., warden or devise):

# initializers/admin_access.rb

class CanAccessFlipperUI
  def self.matches?(request)
    current_user = request.env['warden'].user
    current_user.present? && current_user.respond_to?(:admin?) && current_user.admin?
  end
end

# config/routes.rb

constraints CanAccessFlipperUI do
  mount Flipper::UI.app(flipper) => '/flipper'
end

Standalone

Minimal example for Rack:

# config.ru

require 'flipper-ui'
require 'flipper/adapters/memory'

adapter = Flipper::Adapters::Memory.new
flipper = Flipper.new(adapter)

run Flipper::UI.app(flipper) { |builder|
  builder.use Rack::Session::Cookie, secret: "something long and random"
}

The key is that you need to have sessions setup. Rails does this for you, so this step isn't necessary, but for standalone rack, you'll need it. Without sessions setup, you will receive a Runtime error like:

RuntimeError: you need to set up a session middleware *before* Rack::Protection::RemoteToken.

See examples/ui/basic.ru for a more full example

Configuration

Flipper UI can be customized via configure, which yields a configuration instance for setting the text on the five main sections of the UI feature view.

• config.actors
• config.groups
• config.percentage_of_actors
• config.percentage_of_time
• config.delete

Each of these methods returns a Flipper::UI::Option that responds to title=, description= as seen below.

e.g. customzing the percentage_of_actors and delete sections' titles and descriptions

Flipper::UI.configure do |config|
  config.percentage_of_actors.title = "My Custom Title"
  config.percentage_of_actors.description = "My custom description"

  config.delete.title = "BE VERY CAREFUL!"
  config.delete.description = "YOU'VE BEEN WARNED!"
end

results in:

Contributing

1. Fork it
2. Create your feature branch (git checkout -b my-new-feature)
3. Fire up the app (script/server)
4. Start up guard (bundle exec guard for automatic coffeescript/sass compilation and such).
5. Commit your changes (git commit -am 'Added some feature')
6. Push to the branch (git push origin my-new-feature)
7. Create new Pull Request