Ruby on Rails & PostgreSQL - v2

Ruby on Rails & PostgreSQL - v2

• 1.
  Ruby-on-Rails & PostgreSQL John Ashmead
• 2.
  Ruby-on-Rails • Based on Ruby • AFramework, like Django • Widely popular • Ruby + ActiveRecord + Lots of Web Stuff + Lots of other Stuff • Michael Hardt: http://ruby.railstutorial.org
• 3.
  Ruby Version Manager • RVM letsyou run multiple versions of ruby • Copies everything into some trees, then switches pointers around • Manages gems & gemsets • Bundle install, bundle update
• 4.
  Gemfile source 'https://rubygems.org' ! ruby '2.0.0' ! #Make sure we are using latest ‘rails’ gem 'rails', '4.0.0' ! # Use Postgres as the database for Active Record gem 'pg' ! # Use SCSS for stylesheets gem 'sass-rails', '~> 4.0.0' ! # switch to bootstrap, rspec, factory_girl, selenium, capybara ! …
• 5.
  ActiveRecord • Database adaptor id • General purpose name • Conventionover configuration • Reasonable defaults • Standalone product maps description created_at updated_at
• 6.
  Finally, PostgreSQL • ‘pg’ gem • ProvidesActiveRecord with interface to Postgres • AR has an “execute” function that lets you run raw sql • ‘postgres-pr’ gem gives access to PostgreSQL specific features, if needed
• 7.
  Foreign Keys • ActiveRecord hasa lot of “associations” • Has_many, belongs_to, has_and_belongs_to_many • Doesn’t clean up the existing database • Doesn’t automatically generate the relevant keys • Doesn’t fix the metadata
• 8.
  create_table "maps", force:true do |t| t.integer "user_id" t.string "map_type", t.string "name" t.text "description" t.decimal "map_width" t.decimal "map_height" t.datetime "created_at" t.datetime "updated_at" end CREATE TABLE maps ( id integer NOT NULL, user_id integer, map_type character varying(255), name character varying(255), description text, map_width numeric, map_height numeric, created_at timestamp without time zone, updated_at timestamp without time zone ); Weirder than it looks
• 9.
  Migrations rails generate scaffoldMap user_id:integer map_type:string name:string description:text map_width:decimal map_height:decimal class CreateMaps < ActiveRecor def change create_table :maps do |t| t.integer :user_id t.string :map_type, t.string :name, t.text :description t.decimal :map_width t.decimal :map_height ! t.timestamps end end end rake db:migrate && rails db:migrate RAILS_ENV=test
• 10.
  Heroku stack • Ruby-on-Rails frontend • PostgreSQL preferred • Well documented • Free up to a reasonable point • Integrated with github • Lots of tools • Mostly works • https://www.heroku.com
• 11.
  Red Green Refactor • Agile & Stories • Examples& TDD (Testdriven development) over APIs • MVC: Model/View/ Controller • Upgrades in RoR much trickier than in PostgreSQL
• 12.
  Domain Specific Languages • • PostgreSQLmakes it easy to hook existing languages in: i.e. Javascript as a server language. • Gems versus packages. About 30K gems! Of widely varying quality. • YMMV describe "home page" do let!(:person) { FactoryGirl.create(:person) } } Ruby makes it easy to write DSLs before { sign_in person visit home_people_path(person) } it { should have_content(person.name) it { should have_title(person.name) } end
• 13.
  Long learning curves • Ruby-on-railshas a lot of levels • Achieving rapport with rails takes time • Help: railscasts, stackoverflow, … • Grow little neurons, grow (damn you!)
• 14.
  There’s a pagefor that • http://localhost:8081/phpPgAdmin/ • http://guides.rubyonrails.org • http://api.rubyonrails.org • https://codeclimate.com • http://localhost:3000 • https://github.com • http://ruby.railstutorial.org/book/ruby-on-rails-tutorial? version=4.0 • http://ruby-doc.com/docs/ProgrammingRuby/ • …