How to determine if a record was created or updated in after_save callback (Ruby on Rails)
sometimes in after_save callback it is needed to determine if a record was created or updated without the use of after_create callback.
update_attribute, update_attributes and update_column (Ruby on Rails)
attr_accessor vs attr_accessible (Ruby on Rails)
The post describes what mean ‘attr_accessor’ and ‘attr_accessible’ in a Rails Model.
Regular Expressions in Ruby
Ruby uses Perl-compatible regular expressions, so if you’re familiar with the preg_*functions in PHP, it will be easy to learn regular expressions in Ruby.