我正在使用Rails 3.2.2,使用aasm gem,我有这样的Document模型：
class Document < ActiveRecord::Base
include AASM
aasm do
state :unread,:initial => true
state :read
state :closed
event :view do
transitions :to => :read,:from => [:unread]
end
event :close do
transitions :to => :closed,:from => [:read,:unread]
end
end
现在在我的控制台上：
➜ ✗ bundle exec rails c Loading development environment (Rails 3.2.2) irb(main):006:0> Document.create!(:title => 'test') (0.2ms) BEGIN sql (0.3ms) INSERT INTO `documents` (`aasm_state`,`checklist_id`,`created_at`,`description`,`dir`,`planned_date`,`procedure_id`,`section`,`subsection`,`title`,`updated_at`) VALUES (0,NULL,'2012-06-16 20:03:18','test','2012-06-16 20:03:18') (0.4ms) COMMIT => #<Document id: 28,title: "test",description: nil,dir: nil,section: nil,subsection: nil,planned_date: nil,procedure_id: nil,checklist_id: nil,created_at: "2012-06-16 20:03:18",updated_at: "2012-06-16 20:03:18",aasm_state: 0> irb(main):007:0> doc = Document.last Document Load (0.3ms) SELECT `documents`.* FROM `documents` ORDER BY `documents`.`id` DESC LIMIT 1 => #<Document id: 28,aasm_state: 0> irb(main):008:0> doc.view! NoMethodError: undefined method `name' for nil:NilClass from /Library/Ruby/Gems/1.8/gems/aasm-3.0.6/lib/aasm/supporting_classes/state.rb:15:in `==' from /Library/Ruby/Gems/1.8/gems/aasm-3.0.6/lib/aasm/aasm.rb:143:in `aasm_state_object_for_state' from (irb):8:in `find' from /Library/Ruby/Gems/1.8/gems/aasm-3.0.6/lib/aasm/aasm.rb:143:in `each' from /Library/Ruby/Gems/1.8/gems/aasm-3.0.6/lib/aasm/aasm.rb:143:in `find' from /Library/Ruby/Gems/1.8/gems/aasm-3.0.6/lib/aasm/aasm.rb:143:in `aasm_state_object_for_state' from /Library/Ruby/Gems/1.8/gems/aasm-3.0.6/lib/aasm/aasm.rb:158:in `aasm_fire_event' from /Library/Ruby/Gems/1.8/gems/aasm-3.0.6/lib/aasm/base.rb:48:in `view!' from (irb):8
正如你所看到的,我一直在努力
undefined method `name’ for nil:NilClass
我正在使用Ruby 1.8.7.