rstacruz

Rails Models

Generating models

$ rails g model User

Associations

belongs_to

has_one

jordan-brough

# See http://jordan.broughs.net/archives/2012/07/enumerablecount_by-for-ruby

# Ruby >= 1.8.7 (incl 1.9.x)

module Enumerable
  def count_by(&block)
    Hash[group_by(&block).map { |key,vals| [key, vals.size] }]
  end
end

shunchu

t = 236 # seconds
Time.at(t).utc.strftime("%H:%M:%S")
=> "00:03:56"

# Reference
# http://stackoverflow.com/questions/3963930/ruby-rails-how-to-convert-seconds-to-time

joyrexus

Sans jQuery

Events

// jQuery
$(document).ready(function() {
  // code
})

malchak

# Question:

  # Suppose you have an array of 99 numbers. 
  # The array contains the digits 1 to 100 with one digit missing. 
  # Write four different algorithms to compute the missing number. 
  # Two of these should optimize for low storage and two of these should optimize for fast processing.
  # (Keep in mind, there are no duplicates and the array is not already sorted.)

#######################################################

zvlex

# Generate SHA256 hash
require 'digest'
Digest::SHA256.hexdigest "your_string"

# Generate UUID
SecureRandom.uuid.split('-').join

promisedlandt

class PolicyTest < ActiveSupport::TestCase
  def assert_permissions(current_user, record, available_actions, permissions_hash = {})
    permissions_hash.each do |action, should_be_permitted|
      if should_be_permitted
        assert_permit current_user, record, action
      else
        refute_permit current_user, record, action
      end
    end

mlanett

HTTP status code symbols for Rails

Thanks to Cody Fauser for this list of HTTP responce codes and their Ruby on Rails symbol mappings.

Status Code Symbol
1xx Informational
100 :continue
101 :switching_protocols
102 :processing

mandiwise

// Reference: http://lea.verou.me/2011/10/easily-keep-gh-pages-in-sync-with-master/

$ git add .
$ git status // to see what changes are going to be commited
$ git commit -m 'Some descriptive commit message'
$ git push origin master

$ git checkout gh-pages // go to the gh-pages branch
$ git rebase master // bring gh-pages up to date with master
$ git push origin gh-pages // commit the changes

nepsilon

How to change your commit messages in Git?

At some point you’ll find yourself in a situation where you need edit a commit message. That commit might already be pushed or not, be the most recent or burried below 10 other commits, but fear not, git has your back 🙂.

Not pushed + most recent commit:

git commit --amend

This will open your $EDITOR and let you change the message. Continue with your usual git push origin master.