A template to build large scale web applications in Ruby On Rails. Focus on extending, performance and best practices by applying patterns: Service Objects, Form Objects, Query Objects, Calculation Objects, Value Objects, Policy Objects, Decorators, etc.
- Ruby version:
ruby 2.6.3 - Rails version:
rails 5.2.3 - Database:
postgresql
- Rubocop config
- Codeclimate config
- Basic devise authentication setup
- View template render by slim
- Support Javascript ES6 in Assets Pipeline
- Page-specific Javascript with punchbox
- Easier form helpers with simple_form
- Pagination with kaminari
- PDF generator with wicked_pdf
- Email preview in the browser instead of sending with letter_opener
- CSS styled email without the hassle with premailer-rails
- Annotate rails classes with schema and routes info annotate_models
- Performance checking in development environment with bullet and rack-mini-profiler
- Environment variables loading with dotenv
- Sidekiq default for Active Job queue adapter
- Carrierwave file upload (development, test evironments: local file storage - staging, production: AWS S3 fog storage)
- Full settings for testing application: rspec, factory_bot_rails, faker, shoulda-matchers, webmock, vcr
- Error tracking config in production with Sentry
- Base class init for common patterns in rails application: Service Objects, Form Objects, Query Objects, Calculation Objects, Value Objects, Policy Objects, Decorators, etc
- Make sure that you have installed ruby, rails, redis and postgresql. Read this guide to install if you don't have.
- Clone this repo using
git clone --depth=1 git@github.com:GoldenOwlAsia/go_rails_template.git <YOUR_PROJECT_NAME> - Move to the appropriate directory:
cd <YOUR_PROJECT_NAME> - Install correct ruby version for our project. If you have
rbenv, use these commands:
rbenv install 2.6.3
rbenv local 2.6.3
- Install bundler:
gem install bundler - Install gems:
bundle install - Add database config: create
config/database.ymlfile (refer fromconfig/database.yml.example) - Add environment variables: create
.envfile (refer from.env.example) - Database setup:
bundle exec rake db:setup - Run sidekiq (make sure redis service is running):
bundle exec sidekiq - Start server:
rails s - Visit
http://localhost:3000and start your development
- Start to run your specs by:
bundle exec rspec - See coverage by open
coverage/index.htmlin web browser
app
├── assets
│ ├── javascripts
│ │ ├── application.js.es6
│ │ ├── cable.js.es6
│ │ ├── channels
│ │ └── views
│ │ └── home.js.es6
│ └── stylesheets
│ └── views
│ │ ├── home.scss
│ │ └── variables.scss
│ ├── common
│ │ ├── fonts.scss
│ │ └── variables.scss
│ └── application.scss
├── calculations
│ └── application_calculation.rb
├── controllers
│ ├── concerns
│ ├── application_controller.rb
│ └── home_controller.rb
├── decorators
│ ├── application_decorator.rb
│ └── paginating_decorator.rb
├── forms
│ └── application_form.rb
├── helpers
│ └── application_helper.rb
├── jobs
│ └── application_job.rb
├── mailers
│ └── application_mailer.rb
├── models
│ ├── concerns
│ └── application_record.rb
├── policies
│ └── application_policy.rb
├── queries
│ └── application_query.rb
├── services
│ └── application_service.rb
├── value_objects
│ └── application_value_object.rb
└── views
├── devise
├── home
├── layouts
└── shared
In software engineering, a software design pattern is a general, reusable solution to a commonly occurring problem within a given context in software design. It is not a finished design that can be transformed directly into source or machine code. It is a description or template for how to solve a problem that can be used in many different situations. Design patterns are formalized best practices that the programmer can use to solve common problems when designing an application or system.
Service objects are commonly used to mitigate problems with model callbacks that interact with external classes (read more). Service objects are also useful for handling processes involving multiple steps. E.g. a controller that performs more than one operation on its subject (usually a model instance) is a possible candidate for Extract ServiceObject (or Extract FormObject) refactoring. In many cases service object can be used as scaffolding for replace method with object refactoring. Some more information on using services can be found in this article.
Defining:
class ActivateUserService < ApplicationService
attr_reader :user
def initialize(user)
@user = user
end
def call
user.activate!
NotificationsMailer.user_activation_notification(user).deliver_later
user
end
end
Usage:
user = User.find(params[:id])
ActivateUserService.call(user)
Form objects, just like service objects, are commonly used to mitigate problems with model callbacks that interact with external classes (read more). Form objects can be used as wrappers for virtual (with no model representation) or composite (saving multiple models at once) resources. In the latter case this may act as replacement for ActiveRecord::NestedAttributes. In some cases FormObject can be used as scaffolding for replace method with object refactoring. Some more information on using form objects can be found in this article.
Defining:
class UserRegistrationForm < ApplicationForm
attr_accessor :user, :terms_of_service
delegate :attributes=, to: :user, prefix: true
validates :terms_of_service, acceptance: true
def initialize(user, params = {})
@user = user
super(params)
end
def submit
return false if invalid?
user.save
end
def persisted?
user.persisted?
end
end
Usage:
user = User.new
form = UserRegistrationForm.new(user, permitted_params)
form.submit
One should consider using query objects pattern when in need to perform complex querying on active record relation. Usually one should avoid using scopes for such purpose. As a rule of thumb, if scope interacts with more than one column and/or joins in other tables, it should be moved to query object. Also whenever a chain of scopes is to be used, one should consider using query object too. Some more information on using query objects can be found in this article.
Defining:
class RecentlyActivatedUsersQuery < ApplicationQuery
query_on 'User'
def call
relation.active.where(activated_at: date_range)
end
private
def date_range
options.fetch(:date_range, default_date_range)
end
def default_date_range
Date.yesterday.beginning_of_day..Date.current.end_of_day
end
end
Usage:
RecentlyActivatedUsersQuery.call
RecentlyActivatedUsersQuery.call(date_range: Date.today.beginning_of_day..Date.today.end_of_day)
RecentlyActivatedUsersQuery.call(User.male, date_range: Date.today.beginning_of_day..Date.today.end_of_day)
Calculation objects provide a place to calculate simple values (i.e. numeric, arrays, hashes), especially when calculations require interacting with multiple classes, and thus do not fit into any particular one.
Defining:
class AverageHotelDailyRevenueCalculation < ApplicationCalculation
def call
reservations.sum(:price) / number_of_days_in_year
end
private
def reservations
Reservation.where(
date: (beginning_of_year..end_of_year),
hotel_id: options[:hotel_id]
)
end
def number_of_days_in_year
end_of_year.yday
end
def year
options[:year] || Date.current.year
end
def beginning_of_year
Date.new(year).beginning_of_year
end
def end_of_year
Date.new(year).end_of_year
end
end
Usage:
hotel = current_user.owned_hotel
AverageHotelDailyRevenueCalculation.call(hotel_id: hotel.id)
AverageHotelDailyRevenueCalculation.call(hotel_id: hotel.id, year: 2018)
The Value Object design pattern encourages simple, small objects (which usually just contain given values), and lets you compare these objects according to a given logic or simply based on specific attributes (and not on their identity).
Read more at value_objects document.
Defining:
class AddressValueObject < ApplicationValueObject
attr_accessor :street, :postcode, :city
validates :postcode, presence: true
validates :city, presence: true
end
Usage:
address = AddressValueObject.new(street: '123 Big Street', city: 'Metropolis')
address.valid? # => false
address.errors.to_h # => {:postcode=>"can't be blank"}
address.postcode = '12345' # => "12345"
address.valid? # => true
address.errors.to_h # => {}
Usage in Active Record:
class User < ActiveRecord::Base
include ValueObjects::ActiveRecord
value_object :company_addresses, AddressValueObject::Collection
value_object :home_address, AddressValueObject
end
The Policy Objects design pattern is similar to Service Objects, but is responsible for read operations while Service Objects are responsible for write operations. Policy Objects encapsulate complex business rules and can easily be replaced by other Policy Objects with different rules. For example, we can check if a guest user is able to retrieve certain resources using a guest Policy Object. If the user is an admin, we can easily change this guest Policy Object to an admin Policy Object that contains admin rules.
Read more at pundit document.
Defining:
class ArticlePolicy < ApplicationPolicy
def create?
user.admin?
end
def update?
user.admin? && !record.published?
end
end
Usage:
@article = Article.find(params[:id])
authorize @article, :update?
@article.update(article_params)
The Decorator Pattern allows us to add any kind of auxiliary behavior to individual objects without affecting other objects of the same class. This design pattern is widely used to divide functionality across different classes, and is a good alternative to subclasses for adhering to the Single Responsibility Principle.
Read more at draper document.
Define:
class ArticleDecorator < Draper::Decorator
delegate_all
def publication_status
if published?
"Published at #{published_at}"
else
"Unpublished"
end
end
def published_at
object.published_at.strftime("%A, %B %e")
end
end
Usage:
article = Article.find(params[:id]).decorate
article.publication_status
article.published_at
For deployment, you can use AWS Elastic Beanstalk Service (AWS EB) which have most interesting parts from my experiences:
- Handles the deployment process, you just need to bundle the app and send to EB then you’re free to do others thing. Don’t need to wait for processing tasks via SSH connection, as result in speed up your development.
- Handles load balancing, auto-scaling by triggered to the app health monitoring. You can easy to setting up from EB management console.
- And finally, no additional charge for using EB. If you are using the same resources (EC2, CloudFront, S3, RDS, Route 53, ElasticCache,…) then EB won’t add more charges to your bill.
I have written a complete guide to deploy rails application to AWS EB. Please take a look on it.
Licensed under the MIT license, see the separate LICENSE.md file.