Alex Popov AlexVPopov

Rails Migration

http://guides.rubyonrails.org/migrations.html

Migrations methods:

add_column
add_index
change_column
change_table
create_table
drop_table

Deploy Rails app to digitalocean with nginx, unicorn, capistrano & postgres

Create droplet of your liking (ubuntu 12.10 x32)

ssh to root in terminal with your server ip

ssh [email protected]

Add ssh fingerprint and enter password provided in email

Chapter 1 - Object Oriented Design

The purpose of design is to allow you to do design later, and it's primary goal is to reduce the cost of change.

SOLID Design:

Single Responsibility Principle: a class should have only a single responsibility
Open-Closed Principle: Software entities should be open for extension, but closed for modification (inherit instead of modifying existing classes).
Liskov Substitution: Objects in a program should be replaceable with instances of their subtypes without altering the correctness of that program.
Interface Segregation: Many client-specific interfaces are better than one general-purpose interface.

Launch Sublime Text from the command line on OSX

Sublime Text includes a command line tool, subl, to work with files on the command line. This can be used to open files and projects in Sublime Text, as well working as an EDITOR for unix tools, such as git and subversion.

Requirements

Sublime text 2 or 3 installed in your system within Applications folder

Setup

Thoughts about Rails Presenters

This is a collection of links, examples and rants about Presenters/Decorators in Rails.

The "Decorator" pattern slowly started gaining popularity in Rails several years ago. It is not part of core Rails, and there's many different interpretations about how it should work in practice.

Jay Fields wrote about it in 2007 (before he switched back to Java and then Clojure): http://blog.jayfields.com/2007/03/rails-presenter-pattern.html

	#!/usr/bin/env bash

	uninstall() {
	list=`gem list --no-versions`
	for gem in $list; do
	gem uninstall $gem -aIx
	done
	gem list
	gem install bundler
	}

	{
	"USD": {
	"symbol": "$",
	"name": "US Dollar",
	"symbol_native": "$",
	"decimal_digits": 2,
	"rounding": 0,
	"code": "USD",
	"name_plural": "US dollars"
	},

	#
	# At CoverHound, we use conditional validations all over the form. However, there is no proper way to do
	# this in Rails. Instead, we can provide an array of attributes (validated_fields attribute)
	# and ensure they are the only ones to get validated.
	#

	module ConditionalValidations
	attr_accessor :validated_fields

	def field_is_required?(field)

	class Ticket < ActiveRecord::Base
	belongs_to :grouper
	belongs_to :user

	validate :user_cant_be_blacklisted, on: :confirmation
	validate :user_cant_double_book, on: :confirmation

	validate :grouper_cant_be_full, on: :confirmation
	validate :grouper_cant_have_occurred, on: :confirmation


	# 1) Create your private key (any password will do, we remove it below)

	$ cd ~/.ssh
	$ openssl genrsa -des3 -out server.orig.key 2048


	# 2) Remove the password

	$ openssl rsa -in server.orig.key -out server.key