Notes

my_company.serializable_hash(:include => [:people])

%Q doesn't return microseconds but milliseconds! Use %s%6N for microseconds.

%Q doesn't return microseconds but milliseconds! Use %s%6N for microseconds.

...

validates_presence_of is a holdover from the Rails 2 days.

This is the way it is done now http://guides.rubyonrails.org/active_record_validations_callbacks.html#presence

What is the purpose of

Hash[one: 1, two: 1]

When you can write

{one: 1, two: 2}

Aren't you just passing a hash into the [] method?

Its supposed to be http caching, but Rails will actually cache the response to whatever you specified as the cache store, as well, but only if you specify :public => true. The default is filestore so it will try to write to tmp/cache.

Only a problem if you don't have the proper permissions set, i...

http://stackoverflow.com/questions/1727217/file-open-open-and-io-foreach-in-ruby-what-is-the-difference

Note, if you're using the code below for incrementing by SQL with a Postgres database, it's not going to like the backticks. Just remove them:

def increment_with_sql!(attribute, by = 1)
raise ArgumentError("Invalid attribute: #{attribute}") unless attribute_names.include?(attribute.to_s)...

Hey, guys!

You have one mistake in example code.

uri = URI('https://secure.example.com/some_path?query=string')

Net::HTTP.start(uri.host, uri.port,
:use_ssl => uri.scheme == 'https').start do |http|
request = Net::HTTP::Get.new uri.request_uri

response = http.request re...

Pass in array instead of list h = { "cat" => "feline", "dog" => "canine", "cow" => "bovine" }

keys_i_want = %w(cow cat)

h.values_at(*keys_i_want) #=> ["bovine", "feline"]

concat method will be useful to join the collection object from looping conditions.

arr = ["a", "b", "c"]
content_tag(:ul, :class => 'a class') do
arr.each do |item|
concat content_tag(:li, item)
end

And this will generate the html as shown below

<ul class="a class">...

'I am 中国人'.encode('gbk','utf-8')

require 'kconv'

then

“中国人民很行”.toutf8

.

Have look how #between? handle adge case. It's different from DateTime's.

Date.yesterday.between?(Date.yesterday, Date.tomorrow)
=> true


Date.tomorrow.between?(Date.yesterday, Date.tomorrow)
=> true

The non-repeating primary key id must be used with find_in_batches.

• User has many things
• User has many socks through things
• Sock has many things
• Sock has many users through things

For the sake of argument, assume the first user has two socks and all other users have one sock. There are 10...

This is out of date for Rails 3; instead see ActiveRecord::Persistence#update_attributes

A serialized attribute will always be updated during save, even if it was not changed. (A rails 3 commit explains why: http://github.com/rails/rails/issues/8328#issuecomment-10756812)

Guard save calls with a changed? check to prevent issues.

class Product < ActiveRecord::Base
serialize :pr...

Mange made me think, and I wanted to expand on his example with a small change.

class Hash
def without(*keys)
  dup.without!(*keys)
end

def without!(*keys)
  reject! { |key| keys.include?(key) }
end
end

h = { :a => 1, :b => 2, :c => 3 }
h.without(:a)      #...