10 Rails console tricks

Posted on 20 December 2009

Invoking helper methods

>> helper.number_to_currency('123.45')

Method definition finder (irb)

>> helper.method(:truncate)
=> #<Method: ActionView::Base(ActionView::Helpers::TextHelper)#truncate>

>> "".method(:camelize)
=> #<Method: String(ActiveSupport::CoreExtensions::String::Inflections)#camelize>

Method finder (irb)

$ gem install what_methods

>> require 'what_methods'
>> "foo ".what? "foo"
"foo ".chop! == "foo"
"foo ".chop == "foo"
"foo ".strip! == "foo"
"foo ".strip == "foo"
"foo ".rstrip! == "foo"
"foo ".rstrip == "foo"
=> ["chop!", "chop", "strip!", "strip", "rstrip!", "rstrip"]

Method lookup (irb)

>> "".methods.grep(/case/).sort
=> ["camelcase", "casecmp", "downcase", "downcase!", "swapcase", "swapcase!", "titlecase", "upcase", "upcase!"]

Avoid screenfuls of objects (irb)

>> people = Person.all; nil
=> nil

Rollback database modifications on exit

$ ./script/console --sandbox

Last expression (irb)

>> Person.first
=> #<Person id: 1, first_name: "Dejan" ... >
>> _.first_name
=> "Dejan"

Reload code changes

>> reload!

Better object format (irb)

>> y User.first
--- !ruby/object:User 
attributes: 
  hashed_password: 123456789cde83xa9b86e36e4627360
  last_seen_at: 2009-12-09 13:16:44
  username: dejan
  id: "1"
  created_at: 2007-01-14 17:30:00
attributes_cache: {}

script/console logging

You need this.

>> User.cached(:first)
==> Got User:first from cache. (0.10173)
  User Load (300.1ms)   SELECT * FROM `users` LIMIT 1
==> Set User:first to cache. (0.01512)
=> #<User id: 1, username: "dejan", ... >

>> User.cached(:first)
==> Got User:first from cache. (0.00061)
=> #<User id: 1, username: "dejan", ... >

>> User.expire_cache(:first)
==> Deleted User:first from cache. (0.00059)
=> true