ilake

[1] pry(main)> Digest::MD5.new.update('version-1')
=> #<Digest::MD5: e8444fc50e000a592c6f49872490349e>
[2] pry(main)> Digest::MD5.new.update('version-1').update('mini-2')
=> #<Digest::MD5: 9f328f25432758cd63ba0ddd38024364>
[3] pry(main)> Digest::MD5.new.update('version-1').update('mini-2').hexdigest
=> "9f328f25432758cd63ba0ddd38024364"

[4] pry(main)> Digest::MD5.hexdigest('version-1')
=> "e8444fc50e000a592c6f49872490349e"

ilake

# For sprockets-2.1.3

# in lib/sprockets/asset.rb 
# Asset class, initialize method
# just use path
      @digest       = environment.file_digest(pathname).hexdigest
      puts "========== Assets::initialize:pathname #{pathname}"
      puts "========== Assets::initialize:@digest #{@digest}"

ilake

    begin 
      raise 
    rescue => e 
      logger.error e.message 
      e.backtrace.each { |line| logger.error line } 
    end 

ilake

 <script src="//ajax.googleapis.com/ajax/libs/jquery/1.8.3/jquery.min.js"></script>
<script>
$(document).ready(function(){
  $("#button").click(function()   
  // Do anything you want here
    return false // cancel default action
  );
});
</script>

ilake

# & then proc object into block
# & also could then block into a proc object
# & 可以讓proc object 跟 block 切來切去

# Calling a method with & in front of a parameter
tweets.each(&printer)  # turns a proc into block

# Defining a method with & in front of a parameter
def each(&block) # turns a block into a proc, so it can be assigned to parameter

ilake

# YIELD - ARGUMENTS
def call_this_block
  yield "tweet"
end

call_this_block { |myarg| puts myarg.upcase }  # => TWEET


Timeline
  def each

ilake

config.assets.precompile << Proc.new { |path|
  if path =~ /\.(css|js)\z/
    full_path = Rails.application.assets.resolve(path).to_path
    app_assets_path = Rails.root.join('app', 'assets').to_path
    if full_path.starts_with? app_assets_path
      puts "including asset: " + full_path
      true
    else
      puts "excluding asset: " + full_path
      false

ilake

Image.ancestors        # [Image, ImageUtils, Object, Kernel, BasicObject]
Image.included_modules # [ImageUtils, Kernel]

class Image
  image = Image.new
  image.extend(ImageUtils)
  image.preview # an object is extending the module
end

# the module will not be available in other objects

ilake

array.from(4)
array.to(2)
array.in_groups_of(3)
array.split(2)
array.index('word')

apocalypse = DateTime.new(2012, 12, 21, 14, 27, 45)
apocalypse.advance(years: 4, months: 3, weeks: 2, days: 1)
apocalypse.tomorrow
apocalypse.yesterday

ilake

# http://blog.mitchcrowe.com/blog/2012/04/14/10-most-underused-activerecord-relation-methods/
1. Merge
class Account < ActiveRecord::Base
  # ...

  # Returns all the accounts that have unread messages.
  def self.with_unread_messages
    joins(:messages).merge( Message.unread )
  end
end