Flipside

Flipside is a gem for managing feature flags in your Rails applications.

• enable or disable features globally
• enable features for specific records (e.g. users, organizations)
• enabled features for objects responding true to a certain method
• Setting a start and end time for when the feature is active

Install the gem and add to the application's Gemfile by executing:

$ bundle add flipside

If bundler is not being used to manage dependencies, install the gem by executing:

$ gem install flipside

Then run

$ rails generate flipside:install

This will create a migration file. Run the migration, to add the flipside tables

$ rails db:migrate

1. Defining Features

Features are created by running this (in a console or from code):

Flipside::Feature.create(
  name: "MyFeature",
  description: "Some optional description about what this feature do"
)

By default features are turned off. If you would like it turned on from the beginning you could pass in enabled: true.

Flipside::Feature.create(name: "MyFeature", enabled: true)

Features can be active during a given period. Set activated_at and/or deactivated_at to define this period. Note: A feature is always disabled outside of the active period.

Flipside::Feature.create(
  name: "MyFeature",
  activated_at: 1.week.from_now,
  deactivated_at: 2.weeks.from_now
)

Features can be enabled for a certain record, typically a certain record or organization. This records are called entities. To enable a feature for a given record use.

user = User.first
Flipside.enabled? user # => false
Flipside.add_entity(name: "MyFeature", user)
Flipside.enabled? user # => true

Features can be enabled for records responding true to a certain method. This is called a "role". Given that User records have an admin? method. A feature can then be enabled for all users how are admins.

user1 = User.new(admin: false)
user2 = User.new(admin: true)
Flipside.add_role(
  name: "MyFeature",
  class_name: "User",
  method_name: :admin?
)
Flipside.enabled? user1 # => false
Flipside.enabled? user2 # => true

2. Checking Feature Status

Check if a feature is enabled globally:

Flipside.enabled? "MyFeature"

Check if a feature is enabled for a specific record (e.g. a user):

Flipside.enabled? "MyFeature", user

Flipside comes with a sinatra web ui to mange feature flags. To mount this sinatra app in Rails add the following to your routes.rb file.

mount Flipside::Web, at: '/flipside'

Note: you also probably want to wrap this inside a constraints block to provide some authentication.

After checking out the repo, run bin/setup to install dependencies. Then, run rspec to run the tests.

To install this gem onto your local machine, run bundle exec rake install. To release a new version, update the version number in version.rb, and then run bundle exec rake release, which will create a git tag for the version, push git commits and the created tag, and push the .gem file to rubygems.org.

Bug reports and pull requests are welcome on GitHub at https://github.com/[sammyhenningsson]/flipside.

The gem is available as open source under the terms of the MIT License.