MohamedAlaa

tmux shortcuts & cheatsheet

start new:

tmux

start new with session name:

tmux new -s myname

amejiarosario

Rails Migration

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

Migrations methods:

• add_column
• add_index
• change_column
• change_table
• create_table
• drop_table

frsyuki

My thoughts on MessagePack

Hi. My name is Sadayuki "Sada" Furuhashi. I am the author of the MessagePack serialization format as well as its implementation in C/C++/Ruby.

Recently, MessagePack made it to the front page of Hacker News with this blog entry by Olaf, the creator of the Facebook game ZeroPilot. In the comment thread, there were several criticisms for the blog post as well as MessagePack itself, and I thought this was a good opportunity for me to address the questions and share my thoughts.

My high-level response to the comments

To the best of my understanding, roughly speaking, the criticisms fell into the following two categories.

jboner

Latency Comparison Numbers (~2012)
----------------------------------
L1 cache reference                           0.5 ns
Branch mispredict                            5   ns
L2 cache reference                           7   ns                      14x L1 cache
Mutex lock/unlock                           25   ns
Main memory reference                      100   ns                      20x L2 cache, 200x L1 cache
Compress 1K bytes with Zippy             3,000   ns        3 us
Send 1K bytes over 1 Gbps network       10,000   ns       10 us
Read 4K randomly from SSD*             150,000   ns      150 us          ~1GB/sec SSD

them0nk

#Model 

@user.should have(1).error_on(:username) # Checks whether there is an error in username 
@user.errors[:username].should include("can't be blank")  # check for the error message 

#Rendering
response.should render_template(:index)

#Redirecting 
response.should redirect_to(movies_path)

riyad

# The BootstrapBreadcrumbsBuilder is a Bootstrap compatible breadcrumb builder.
# It provides basic functionalities to render a breadcrumb navigation according to Bootstrap's conventions.
#
# BootstrapBreadcrumbsBuilder accepts a limited set of options:
# * separator: what should be displayed as a separator between elements
#
# You can use it with the :builder option on render_breadcrumbs:
#     <%= render_breadcrumbs :builder => ::BootstrapBreadcrumbsBuilder, :separator => "&raquo;" %>
#
# Note: You may need to adjust the autoload_paths in your config/application.rb file for rails to load this class:

samnang

# Change devise encryption strategy to match your existing authentication
# https://github.com/plataformatec/devise/tree/master/lib/devise/encryptors

class MigrateUsers < ActiveRecord::Migration
  def self.up
    rename_column :users, :crypted_password, :encrypted_password

    add_column :users, :confirmation_token, :string, :limit => 255
    add_column :users, :confirmed_at, :timestamp
    add_column :users, :confirmation_sent_at, :timestamp

rstacruz

Rails Models

Generating models

$ rails g model User

Associations

belongs_to

has_one

vjm

<%= form_for(@user) do |f| %>
  <% if @user.errors.any? %>
    <div id="error_explanation">
      <h2><%= pluralize(@user.errors.count, "error") %> prohibited this user from being saved:</h2>

      <ul>
      <% @user.errors.full_messages.each do |msg| %>
        <li><%= msg %></li>
      <% end %>
      </ul>

kamui

#!/usr/bin/env ruby

# Convert command line
#
#gm convert -font helvetica -fill white -pointsize 20 -draw "text 500,600 'WALLPAPERZ ARE GOOD'" test.jpg output.jpg
#
#convert -background transparent -fill white -gravity center -size 1024x200 -font Helvetica -pointsize 20 #caption:"I'm a wallpaper, you know what to do" test.jpg +swap -gravity south -composite output.jpg
#
# Mogrify command line
#