ruby-on-rails - Rails 4 模型有效，但不会保存？

Question

我有以下型号:

通知

class Notification < ActiveRecord::Base
  belongs_to :notification_path
  before_save :set_default

  def set_default
      self.resolved = false unless self.resolved
  end
end

通知路径

class NotificationPath < ActiveRecord::Base
  has_many :notifications
end

然后这段代码:

notification = Notification.new({"area"=>"test", "severity"=>"10", "message"=>"Test", "notification_path_id" => 3})

 <Notification id: nil, area: "test", severity:
 10, message: "Test", created_at: nil, updated_at: nil,
 notification_path_id: 3, resolved: nil>

notification.valid?

true

notification.errors.full_messages

[]

因此，如您所见 - 通知有效且没有错误。通知模型的验证为零。但是，当我保存模型时:

notification.save

false

它不会保存。这是什么原因造成的？值得注意的是 set_default确实运行成功，即使模型没有保存 resolved尝试保存时属性被设置为 false。

编辑

在 IRB 中遵循上述内容时，下面的完整错误跟踪:

notification.save! ActiveRecord::RecordNotSaved: ActiveRecord::RecordNotSaved from /Users/Jonathan/.rvm/gems/ruby-2.1.1@steel_notify/gems/activerecord-4.1.0.rc1/lib/active_record/persistence.rb:125:in save!' from
/Users/Jonathan/.rvm/gems/ruby-2.1.1@steel_notify/gems/activerecord-4.1.0.rc1/lib/active_record/validations.rb:57:in
save!' from /Users/Jonathan/.rvm/gems/ruby-2.1.1@steel_notify/gems/activerecord-4.1.0.rc1/lib/active_record/attribute_methods/dirty.rb:29:in save!' from
/Users/Jonathan/.rvm/gems/ruby-2.1.1@steel_notify/gems/activerecord-4.1.0.rc1/lib/active_record/transactions.rb:273:in
block in save!' from /Users/Jonathan/.rvm/gems/ruby-2.1.1@steel_notify/gems/activerecord-4.1.0.rc1/lib/active_record/transactions.rb:329:in block in with_transaction_returning_status' from
/Users/Jonathan/.rvm/gems/ruby-2.1.1@steel_notify/gems/activerecord-4.1.0.rc1/lib/active_record/connection_adapters/abstract/database_statements.rb:211:in
block in transaction' from /Users/Jonathan/.rvm/gems/ruby-2.1.1@steel_notify/gems/activerecord-4.1.0.rc1/lib/active_record/connection_adapters/abstract/database_statements.rb:219:in within_new_transaction' from
/Users/Jonathan/.rvm/gems/ruby-2.1.1@steel_notify/gems/activerecord-4.1.0.rc1/lib/active_record/connection_adapters/abstract/database_statements.rb:211:in
transaction' from /Users/Jonathan/.rvm/gems/ruby-2.1.1@steel_notify/gems/activerecord-4.1.0.rc1/lib/active_record/transactions.rb:208:in transaction' from
/Users/Jonathan/.rvm/gems/ruby-2.1.1@steel_notify/gems/activerecord-4.1.0.rc1/lib/active_record/transactions.rb:326:in
with_transaction_returning_status' from /Users/Jonathan/.rvm/gems/ruby-2.1.1@steel_notify/gems/activerecord-4.1.0.rc1/lib/active_record/transactions.rb:273:in save!' from (irb):23 from
/Users/Jonathan/.rvm/gems/ruby-2.1.1@steel_notify/gems/railties-4.1.0.rc1/lib/rails/commands/console.rb:90:in
start' from /Users/Jonathan/.rvm/gems/ruby-2.1.1@steel_notify/gems/railties-4.1.0.rc1/lib/rails/commands/console.rb:9:in start' from
/Users/Jonathan/.rvm/gems/ruby-2.1.1@steel_notify/gems/railties-4.1.0.rc1/lib/rails/commands/commands_tasks.rb:69:in
console' from /Users/Jonathan/.rvm/gems/ruby-2.1.1@steel_notify/gems/railties-4.1.0.rc1/lib/rails/commands/commands_tasks.rb:40:in run_command!' from
/Users/Jonathan/.rvm/gems/ruby-2.1.1@steel_notify/gems/railties-4.1.0.rc1/lib/rails/commands.rb:17:in' from /Users/Jonathan/.rvm/gems/ruby-2.1.1@steel_notify/gems/activesupport-4.1.0.rc1/lib/active_support/dependencies.rb:247:in require' from
/Users/Jonathan/.rvm/gems/ruby-2.1.1@steel_notify/gems/activesupport-4.1.0.rc1/lib/active_support/dependencies.rb:247:in
block in require' from /Users/Jonathan/.rvm/gems/ruby-2.1.1@steel_notify/gems/activesupport-4.1.0.rc1/lib/active_support/dependencies.rb:232:in load_dependency' from
/Users/Jonathan/.rvm/gems/ruby-2.1.1@steel_notify/gems/activesupport-4.1.0.rc1/lib/active_support/dependencies.rb:247:in
require' from /Users/Jonathan/steel_notify/bin/rails:8:in <top
(required)>' from
/Users/Jonathan/.rvm/gems/ruby-2.1.1@steel_notify/gems/activesupport-4.1.0.rc1/lib/active_support/dependencies.rb:241:in
load' from /Users/Jonathan/.rvm/gems/ruby-2.1.1@steel_notify/gems/activesupport-4.1.0.rc1/lib/active_support/dependencies.rb:241:in block in load' from
/Users/Jonathan/.rvm/gems/ruby-2.1.1@steel_notify/gems/activesupport-4.1.0.rc1/lib/active_support/dependencies.rb:232:in
load_dependency' from /Users/Jonathan/.rvm/gems/ruby-2.1.1@steel_notify/gems/activesupport-4.1.0.rc1/lib/active_support/dependencies.rb:241:in load' from
/Users/Jonathan/.rvm/rubies/ruby-2.1.1/lib/ruby/2.1.0/rubygems/core_ext/kernel_require.rb:55:in
require' from /Users/Jonathan/.rvm/rubies/ruby-2.1.1/lib/ruby/2.1.0/rubygems/core_ext/kernel_require.rb:55:in require' from -e:1:in'

Answer 1

在 Ruby 中，赋值返回被赋值的值。在您的情况下，您将 self.resolved 设置为 false。当您从 before_* 回调中准确返回 false 时，它将取消保存操作。完成分配后，您需要返回不是 false 的内容。