What Is New in Rails 5
ApplicationRecord
Similar to ApplicationController which is the common base class for all controllers that you get with new Rails apps, ApplicationRecord will provide a base class for your ActiveRecord models. This provides a common place to put any base model concerns.
app/models/application_record.rb file will be automatically added to models in Rails 5 applications.
# app/models/application_record.rb
class ApplicationRecord < ActiveRecord::Base
self.abstract_class = true
end
ActionCable
Action Cable can integrates websocket with rails application. Action Cable server can handle multiple connection instances. It has only one instance per websocket connection. The client websocker connection(consumer) can subscribe to multiple cable channels.For example Action Cable server can have a ChatChannel and an AppearancesChannel and a consumer(websocket) can subscribe to either one or both of channels.
#Publisher Streams
# app/channels/chat_channel.rb
class ChatChannel < ApplicationCable::Channel
def subscribed
stream_from "chat_#{params[:room]}"
end
end
#Subscriber
// app/javascript/channels/chat_channel.js
import consumer from "./consumer"
consumer.subscriptions.create({ channel: "ChatChannel", room: "Best Room" })
ActiveRecord::Attributes
Define an attribute on a model with type. It is not essential to have a database column with the custom model attribute. attribute can also be used to provide default values.
# db/schema.rb
create_table :profiles, force: true do |t|
t.decimal :gpa
t.string :name, default: "Full Name"
end
# app/models/profile.rb
class Profile < ActiveRecord::Base
end
profile = Profile.new(gpa: '4.1')
# before
profile.gpa # => BigDecimal.new(4.1)
profile.new.name # => "Full Name"
class Profile < ActiveRecord::Base
attribute :gpa, :integer # custom type
attribute :name, :string, default: "Your Name" # default value
attribute :current_time, :datetime, default: -> { Time.now } # default value
attribute :field_without_db_column, :integer, array: true
end
# after
profile.gpa # => 10
Profile.new.name # => "Your Name"
Profile.new.current_time # => 2015-05-30 11:04:48 -0600
model = Profile.new(field_without_db_column: ["1", "2", "3"])
model.attributes # => {field_without_db_column: [1, 2, 3]}
Rails API – ActionController::API
To avoid middlewares used for browser based web applications and server public facing json APIs, we can create API only rails application here after 5.0. rails new my_api --api can be used to generate application which will be API only and will not generate assets and views.
# app/controllers/application_controller.rb
class ApplicationController < ActionController::API
end
Ruby 2.2.2+ required version from Rails 5.0
Ruby 2.2.2+ required version from Rails 5.0