UseCaseFlow

This gem provide easy and readable way to invoke services/use_cases in your controller

Add this line to your application's Gemfile:

gem 'use_case_flow', require: false

And then execute:

$ bundle

Or install it yourself as:

$ gem install use_case_flow

Controllers should take care only on things related to http, like redirect, render , request. response and so on. Writing code became much easier when we invoke our models inside service/use_cases instead in controllers. Imagine code where you invoke some service and then based on result you render special template, or redirect to url and nothing more. From practical point of view we always have one success path and few failures. This gem allow very readable syntax for that case.

To create service you must:

• require use_case_flow
• Method you invoke in controller MUST return instance of Success or Failure
• As example i use return if syntax because it is easiest way to demonstrate how doest it work. You can use other technics but method must return Success or Failure instance

 require "use_case_flow"

  class SomeService
    def call # you can use different name of method 
      return Failure.new(:name_what_was_wrong, 'data put to controller') if semething_go_wrong
      return Failure.new(:email_is_empty, {}) if empty_email? 
      return Failure.new(:user_not_found, User.new ) if user?
      Success.new('data put to controller')   
    end
  end
  
  class UserController
     
    def create
      result = SomeService.new.call
      # order of line below have no matter
      result.name_what_was_wrong { |data_from_service| render :template, json: data_from_service }
      result.email_is_empty { |data_from_service| redirect_to 'www.example.com' }
      result.user_not_found {|new_user| render json: new_user, status: 422}
      result.success{ |text| render plain: text}
    end
  end

example usage from real project, it shows how your controller could looks

• controller
• service

After checking out the repo, run bin/setup to install dependencies. Then, run rake spec to run the tests. Then, run rubocop to run the rubocop ,You can also run bin/console for an interactive prompt that will allow you to experiment.

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 tags, and push the .gem file to rubygems.org.

Bug reports and pull requests are welcome on GitHub at https://github.com/piotr-galas/use_case_flow. This project is intended to be a safe, welcoming space for collaboration, and contributors are expected to adhere to the Contributor Covenant code of conduct.

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