Chanko

http://cookpad.github.io/chanko/

Chanko provides a simple framework for rapidly and safely prototyping new features in your production Rails app, and exposing these prototypes to specified segments of your user base.

With Chanko, you can release many features concurrently and manage target users independently. When any errors are raised from chanko's features, it will be automatically hidden and fallback to its normal behavior.

Requirements

• Ruby >= 2.6.0
• Rails >= 5.0.0

Usage

Add to your Gemfile.

gem "chanko"

Files

Chanko provides a generator to create templates of an unit.

$ rails generate chanko:unit example_unit
      create  app/units/example_unit
      create  app/units/example_unit/example_unit.rb
      create  app/units/example_unit/views/.gitkeep
      create  app/units/example_unit/images/.gitkeep
      create  app/units/example_unit/javascripts/.gitkeep
      create  app/units/example_unit/stylesheets/.gitkeep
      create  app/assets/images/units/example_unit
      create  app/assets/javascripts/units/example_unit
      create  app/assets/stylesheets/units/example_unit

Invoke

You can invoke the logics defined in your units via invoke and unit methods. In controller class context, unit_action utility is also provided. The block passed to invoke is a fallback executed if any problem occurs in invoking.

# app/controllers/users_controller.rb
class UsersController < ApplicationController
  unit_action :example_unit, :show

  def index
    invoke(:example_unit, :index) do
      @users = User.all
    end
  end
end

-# app/views/examples/index.html.slim
= unit.helper_method
= invoke(:example_unit, :render_example)

-# app/units/example_unit/views/_example.html.slim
= foo

Unit

You can see the real example of an unit module file.

module

You can define your MVC code here.

# app/units/example_unit/example_unit.rb
module ExampleUnit
  include Chanko::Unit
  ...
end

active_if

This block is used to decide if this unit is active or not. context is the receiver object of invoke. options is passed via invoke(:foo, :bar, :active_if_options => { ... }). By default, this is set as active_if { true }.

active_if do |context, options|
  true
end

raise_error

By default, any error raised in production env is ignored. raise_error is used to force an unit to raise up errors occured in invoking. You can force all units to raise up errors by Config.raise_error = true.

raise_error

function

In controller or view context, you can call functions defined by function via invoke(:example_unit, :function_name).

scope(:controller) do
  function(:show) do
    @user = User.find(params[:id])
  end

  function(:index) do
    @users = User.active
  end
end

render

The view path app/units/example_unit/views is added into view_paths in invoking. So you can render app/units/example_unit/views/_example.html.slim in invoking.

scope(:view) do
  function(:render_example) do
    render "/example", :foo => hello("world")
  end
end

models

In models block, you can expand model features by expand method. The expanded methods are available via unit proxy like User.unit.active, User.find(params[:id]).unit.active? or User.unit.gc_all_soft_deleted_users.

models do
  expand(:User) do
    scope :active, lambda { where(:deleted_at => nil) }

    def active?
      deleted_at.nil?
    end

    class_methods do
      def gc_all_soft_deleted_users
        where.not(deleted_at: nil).delete_all
      end
    end
  end
end

shared

You can call methods defined by shared in invoking.

shared(:hello) do |world|
  "Hello, #{world}"
end

helpers

You can call helpers in view via unit proxy like unit.helper_method.

helpers do
  def helper_method
    "helper method"
  end
end

Example

https://github.com/cookpad/chanko/tree/master/spec/dummy
Chanko provides an example rails application in spec/dummy directory.

$ git clone [email protected]:cookpad/chanko.git
$ cd chanko/spec/dummy
$ bundle install
$ bundle exec rake db:create db:migrate
$ rails s
$ open http://localhost:3000