Launchkit launchkit-codes

Class methods are methods added on the singleton class of the object.

class Mail
  def self.is_delivered?
    true
  end
  
  self.singleton_class.send(:alias_method, :delivered?, :is_delivered?)
end

###Prerequisites

?> gem install wcr

###Then

?&gt; wcr -l `ls | grep -v -E "LICENSE|Gemfile\.lock"` # chain files that you want to omit.

iconv -f ISO-8859-1 -t UTF-8 your_file.txt > converted_file.txt

###Contact

Thanks for reading. I'm available for freelance work !

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Case statement Behind The Scene

Syntax

A case statement consists of an optional condition followed by zero or more when conditions. It returns the value of the first truthy when statement. Otherwise nil.

str = case "match"

	# Use this pattern instead of a long case when:

	# case cocktail
	# when 'mojito'
	# ["lemon", "mint", "rhum"]
	# ...
	# when 'lemon coke'
	# ["coke", "lemon"]
	# end

	# AR Scoping permit to dinamically build you query in multiple steps

	# Initialize an 'empty' scope
	scope = Pokemon.where(nil)

	scope = scope.select(:id)

	scope = scope.where(created_at: (Time.now - 1.month)..(Time.now))

	scope = scope.limit(5)

	<!DOCTYPE html>
	<html>
	<head>
	<meta name="description" content="react - state">
	<script src="http://fb.me/react-0.13.1.js"></script>
	<meta charset="utf-8">
	<title>JS Bin</title>
	<style id="jsbin-css">
	#spacer{
	margin: 100px 0 20px 0;

	8.to_s(2) # => "00001000"
	6.to_s(2) # => "00000110"
	2.to_s(2) # => "00000010"
	1.to_s(2) # => "00000001"

	(2 & 1).to_s(2) # => "00000000" because it applies an AND operation on each bit. (1 & 1) match
	(2 \| 1).to_s(2) # => "00000011" because it applies an OR operation on each bit. (1 \| 1), (1 \| 0), (0 \| 1) match !
	(6 ^ 2).to_s(2) # => "00000100" because it applies a XOR operation on each bit. (1 \| 0), (0 \| 1) match !
	(8 >> 2).to_s(2) # => "00000010" right-shift operator. Each bit is shifted 2 bits to the right.
	(2 << 2).to_s(2) # => "00001000" left-shift operator. Each bit is shifted 2 bits to the left.

	cell_42 = ['inmate #42', 'inmate #43']

	common_room = ['inmate #40', 'inmate #41', *cell_42, 'inmate #44']
	# => ['inmate #40', 'inmate #41', 'inmate #42', 'inmate #43', 'inmate #44']