blocknotes

# An implementation of static method chaining - like ActiveRecord, for example: Model.where( condition: true )

class Chain
  attr_accessor :ref, :val

  def initialize( ref, val = {} )
    @ref = ref
    @val = val
  end

blocknotes

• Load rails app from irb: require_relative 'config/environment.rb' (after that Rails.application is available)
• Translation key for a model (ex. MyModel): MyModel.model_name.i18n_key
• Clean and recompile assets: rake assets:clean assets:clobber assets:precompile (preperate RAILS_ENV=production to set env)
• Enable/disable cache in development: rake dev:cache
• Dev routes: /rails/info/properties - /rails/info/routes
• Search for notes comments ([TODO], [FIXME], etc.): rake notes
• Dump/restore DB structure: rake db:structure:dump - rake db:structure:load
• Funny method: ActionDispatch::IntegrationTest.i_suck_and_my_tests_are_order_dependent!

blocknotes

# Rails - sometimes it's needed to execute some code before anything else but after Rails core is loaded. A good place to achieve this is using after_initialize in config/application.rb:

# ... config requires ...
module MyApp
  class Application < Rails::Application
    config.after_initialize do
      # init code here...
    end
  end
end

blocknotes

# Ruby offers different ways to extend classes / monkey patch / override methods.
# A good way to execute code before or after a method of a class is using prepend

class Test
  def fun
    puts 'Inside fun()'
  end
end

Test.new.fun

blocknotes

# Set values in new block

class MyClass
  attr_accessor :name, :val
  def initialize
    yield self if block_given?
  end
end

MyClass.new do |obj|

blocknotes

require 'dry-validation'

schema = Dry::Validation.Schema do
  required(:name).filled
  required(:age).maybe(:int?)
  optional(:sex).value( included_in?: %w(M F) )
end

hash = { name: 'Jane', email: '[email protected]' }
hash[:age] = 21

blocknotes

require 'ffi'

# Example 1: libc - puts

module MyLib
  extend FFI::Library
  ffi_lib 'c'
  attach_function :puts, [ :string ], :int
end