prakashmurthy

class ApplicationController < ActionController::Base
  protect_from_forgery with: :exception
  rescue_from ActionController::InvalidAuthenticityToken, with: :show_errors
  
  before_filter { |c| User.current_user = c.current_user }
  
  ...
  private
  
    def show_errors

prakashmurthy

An ActionController::InvalidAuthenticityToken occurred in user_sessions#create:

  ActionController::InvalidAuthenticityToken

-------------------------------
Stack Trace
-------------------------------
ActionController::InvalidAuthenticityToken (ActionController::InvalidAuthenticityToken):
  actionpack (4.2.0) lib/action_controller/metal/request_forgery_protection.rb:181:in `handle_unverified_request'
  actionpack (4.2.0) lib/action_controller/metal/request_forgery_protection.rb:209:in `handle_unverified_request'

prakashmurthy

1. [Act with Prudence](http://programmer.97things.oreilly.com/wiki/index.php/Act with Prudence)

   Notes: Act with prudence and not accrue technical debt by accomplishing things in a quick and dirty manner.

2. Apply Functional Programming Principles

3. Ask "What Would the User Do?" (You Are not the User)

   Notes: We as programmers don't see things the same way as the users do. Need to get better at seeing past one's own experience / perceptions, and learn to see things the way users do. Best way to gather requirements is to watch users do the same activity - better than asking them about it.

4. [Automate Your Coding Standard](http://programmer.97things.oreilly.com/wiki/index.php/Automate Your Coding Standard)

prakashmurthy

class MyObject < ActiveRecord::Base
  ...
  
  protected
  
  def self.find(*args)
    if results = super(*args)
      # Code to add stuff to the my_object.extra_data object
      ...
    end

prakashmurthy

/Users/prakash/.rvm/rubies/ruby-1.9.3-p327/bin/ruby w3c_validator.rb
EEE
Could not validate ./output/3_1_release_notes.html because of 502 "Proxy Error"
EEE
Could not validate ./output/_license.html because of 502 "Proxy Error"
EE
Could not validate ./output/action_mailer_basics.html because of 502 "Proxy Error"
EEEE
Could not validate ./output/active_record_querying.html because of 502 "Proxy Error"

prakashmurthy

## Why would the following code give run time error?
## Inputs to the program:
##    up to 100 entries from STDIN, values range : 1 ≤ n ≤ 10**18
##
inputs = []
while true
  input = $stdin.gets.chomp
  break if input.empty?
  inputs << input.to_i
end

prakashmurthy

$ rails console --sandbox
ruby-1.9.2-rc1 > User.create( :name => "Prakash Murthy", :email => "[email protected]", :password => "abcdefgh", :password_confirmation => "abcdefgh" )
 => #<User id: nil, name: "Prakash Murthy", email: "[email protected]", created_at: nil, updated_at: nil, encrypted_password: nil, salt: nil>

ruby-1.9.2-rc1 > user = User.find_by_email("[email protected]")
 => #<User id: 1, name: "Prakash Murthy", email: "[email protected]", created_at: "2010-12-12 01:42:44", updated_at: "2010-12-12 01:42:44", encrypted_password: nil, salt: nil> 

ruby-1.9.2-rc1 > user.has_password?('abcdefgh')
 => false 

prakashmurthy

$ heroku logs
/home/app/9493b3e5-40a4-4860-bd6c-da4e8664e69e/vendor/require-profiler/lib/require-profiler.rb:90:in `rescue in <top (required)>':  (RuntimeError)

You need to install the term-ansicolor gem to see colorized reports.

	from /home/app/9493b3e5-40a4-4860-bd6c-da4e8664e69e/vendor/require-profiler/lib/require-profiler.rb:87:in `<top (required)>'
	from <internal:lib/rubygems/custom_require>:29:in `require'
	from <internal:lib/rubygems/custom_require>:29:in `require'
	from /home/app/9493b3e5-40a4-4860-bd6c-da4e8664e69e/config/environment.rb:1:in `<top (required)>'
	from <internal:lib/rubygems/custom_require>:29:in `require'

prakashmurthy

prakash-murthys-macbook-air:xmltoy prakashmurthy$ rails g scaffold Feed name:string url:string
/Users/prakashmurthy/.rvm/gems/ruby-1.9.2-p0@xmltoy/gems/nokogiri-1.4.3.1/lib/nokogiri/nokogiri.bundle: [BUG] Segmentation fault
ruby 1.9.2p0 (2010-08-18 revision 29036) [x86_64-darwin10.4.0]

-- control frame ----------
c:0022 p:-541184440 s:0064 b:0064 l:000063 d:000063 TOP   
c:0021 p:---- s:0062 b:0062 l:000061 d:000061 CFUNC  :require
c:0020 p:0186 s:0058 b:0058 l:000057 d:000057 TOP    /Users/prakashmurthy/.rvm/gems/ruby-1.9.2-p0@xmltoy/gems/nokogiri-1.4.3.1/lib/nokogiri.rb:13
c:0019 p:---- s:0056 b:0056 l:000055 d:000055 FINISH
c:0018 p:---- s:0054 b:0054 l:000053 d:000053 CFUNC  :require

prakashmurthy

Percentage of combinations with only one defect per chip = NaN.