(Mac only) When trying to execute “$ bundle install” and the next error occurs: “can’t find header files for ruby at /System/Library/Frameworks/Ruby.framework/Versions/1.8/usr/lib/ruby/ruby.h” you must install “Command Line Tools of Xcode”.


Use $ bundle exec \ to execute any command (like rake) using the gems defined in the Gemfile of your project.


Every thing os generated with:

$ rails generate

can be undone with:

$rails destroy

$ rale db:migrate it’s undone with $ rake db:rollback


$ rails generate controller PageController method1 method2 to generate static pages


Upload to Heroku


scss - sass app/assets/stylesheets/

variable: $grayMediumLight: #eaeaea;
tree:
.center {
  text-align: center;
  h1 {
    margin-bottom: 10px;
  }
}
@mixin box {
 -moz-box-sizing:border-box;
}
.class1 {
 clear:both;
 @include box;
}

rake db:reset # empty db and reload migrations


SampleApp::Application.configure do
  .
  .
  .
  # Force all access to the app over SSL, use Strict-Transport-Security,
  # and use secure cookies.
  config.force_ssl = true
  .
  .
  .
end