markbates

If you're writing web applications with Ruby there comes a time when you might need something a lot simpler, or even faster, than Ruby on Rails or the Sinatra micro-framework. Enter Rack.

Rack describes itself as follows:

Rack provides a minimal interface between webservers supporting Ruby and Ruby frameworks.

Before Rack came along Ruby web frameworks all implemented their own interfaces, which made it incredibly difficult to write web servers for them, or to share code between two different frameworks. Now almost all Ruby web frameworks implement Rack, including Rails and Sinatra, meaning that these applications can now behave in a similar fashion to one another.

At it's core Rack provides a great set of tools to allow you to build the most simple web application or interface you can. Rack applications can be written in a single line of code. But we're getting ahead of ourselves a bit.

lfender6445

Pry Cheat Sheet

• Youtube Tutorial 2013

Command Line

• pry -r ./config/app_init_file.rb - load your app into a pry session (look at the file loaded by config.ru)
• pry -r ./config/environment.rb - load your rails into a pry session

Debugger

ntamvl

How to create a Ruby gem that adds Rake tasks

Create a gem

One way to do this is to use bundler to scaffold our gem:

bundler gem my_gem

Add rake tasks to our gem

I prefer to put tasks meant to manage the gem itself in lib/tasks, and tasks the gem is meant to provide to gem users in lib/my_gem/tasks.

ProGM

Arel Cheatsheet on Steroids

A (more) complete cheatsheet for Arel, including NamedFunction functions, raw SQL and window functions.

Tables

posts = Arel::Table.new(:posts)
posts = Post.arel_table # ActiveRecord

Table alias

leastbad

module ApplicationCable
  class Channel < ActionCable::Channel::Base
    include CableReady::Broadcaster
    delegate :render, to: :ApplicationController
  end
end