Simple Switch

Simple Feature Switch Engine

Requirement

Ruby 2.0+
Rails 4.0+

Installation

Add this line to your application's Gemfile:

gem 'simple_switch'

And then execute:

$ bundle

Or install it yourself as:

$ gem install simple_switch

Usage

Database Strategy

Store and manage features and configurations in database.

Run initialize generator:

$ rails generate simple_switch:initialize

A initializer file named simple_switch.rb will be added into config/initializers after running install generator. Set feature store strategy to :database and leave configuration for yaml strategy commented out.

  # feature management strategy
  # the supported strategies are: [:yml, :database]
  # default strategy is [:database]
  config.feature_store = :database

  # configuration for yml strategy
  # feature switch configuration yaml file stored location, by default it is stored
  # under config directory
  # config.feature_config_file_dir  = 'config'

  # configuration for yml strategy
  # feature switch configuration yaml file name, by default it is 'feature_config.yml'
  # config.feature_config_file_name = 'feature_config.yml'

Then run the following commands to copy required migration files to root application and migrate the database.

$ rails generate simple_switch:install
$ bundle exec rake db:migrate

The data structure for simple_switch is described as followed:

The following rake tasks are created to generate data for features, environments and configurations. You can also add data through rails console.

$ bundle exec rake simple_switch:add_feature name='Foo' description='Foo feature'
$ bundle exec rake simple_switch:add_environment name='test'
$ bundle exec rake simple_switch:add_feature_config feature='foo' environment='test' status=true

Now you can use it in models like this:

class TestModel < ActiveRecord::Base
  ...

  if feature_on?(:foo)
    def foo_method
      ...
    end
  end

  def bar_method
    if feature_on?(:bar)
      ...
    end
  end

  ...
end

In controllers like this:

class TestController < ApplicationController
  ...

  def index
    ...

    if feature_on?(:foo)
      redirect_to :back
    end

    ...
  end

  ...
end

And in views like this:

<% if feature_on?(:foo) %>
  <p>Experiment foo is on</p>
<% end %>

<% if feature_off?(:bar) %>
  <p>Experiment bar is off</p>
<% end %>

YML Strategy

Store and manage features and configurations all in a single yaml file.

Run initialize generator:

$ rails generate simple_switch:initialize

A initializer file named simple_switch.rb will be added into config/initializers after running install generator. Set feature store strategy to :yml and customize the feature configuration yaml file's name and installation place in this file.

  # feature management strategy
  # the supported strategies are: [:yml, :database]
  # default strategy is [:database]
  config.feature_store = :yml

  # configuration for yml strategy
  # feature switch configuration yaml file stored location, by default it is stored
  # under config directory
  config.feature_config_file_dir  = 'config'

  # configuration for yml strategy
  # feature switch configuration yaml file name, by default it is 'feature_config.yml'
  config.feature_config_file_name = 'feature_config.yml'

Then run the following commands to copy feature configuration yaml file to the target directory.

Run install generator:

$ rails generate simple_switch:install

Now you are ready to define features:

foo:
  description: Foo Feature
  states:
    development: true
    test: true
    production: false
bar:
  description: Bar Feature
  states:
    development: true
    test: true
    production: true

Now you can use it in models like this:

class TestModel < ActiveRecord::Base
  ...

  if feature_on?(:foo)
    def foo_method
      ...
    end
  end

  def bar_method
    if feature_on?(:bar)
      ...
    end
  end

  ...
end

In controllers like this:

class TestController < ApplicationController
  ...

  def index
    ...

    if feature_on?(:foo)
      redirect_to :back
    end

    ...
  end

  ...
end

And in views like this:

<% if feature_on?(:foo) %>
  <p>Experiment foo is on</p>
<% end %>

<% if feature_off?(:bar) %>
  <p>Experiment bar is off</p>
<% end %>

Toggle Features

The following methods are only accessible in controllers:

feature_config_info return a hash represents the current feature configuration condition.

turn_on(feature, env) turn on a feature on an indicated environment.

turn_on(:foo, :development)

turn_off(feature, env) turn off a feature on an indicated environment.

turn_off(:foo, :development)

The following rake tasks are created to toggle features for database strategy only, and feature name and environment name are required:

$ bundle exec rake simple_switch:turn_on feature='foo' environment='test'
$ bundle exec rake simple_switch:turn_off feature='foo' environment='test'