Ruby on rails Rails:Error";NoMethodError:未定义的方法`<';对于nil:NilClass";,丢失一些宝石?
这是模型课 类项::项Ruby on rails Rails:Error";NoMethodError:未定义的方法`<';对于nil:NilClass";,丢失一些宝石?,ruby-on-rails,model,gem,ruby-on-rails-plugins,nomethoderror,Ruby On Rails,Model,Gem,Ruby On Rails Plugins,Nomethoderror,这是模型课 类项::项项。有效吗? NoMethodError:undefined method`请注意,您在控制台中创建的项对象的开始日期,结束日期等值为零 然后,比较nil
def validate_start_and_end_date
errors.add(:start_date, "should not be in past") if start_date < Date.today
errors.add(:end_date, "should not be in past") if end_date < Date.today
errors.add(:base, "start date should not be after end date") if end_date < start_date
end
belongs_to :product, {:class_name => 'Item::Product'}
end
def验证开始日期和结束日期
错误。如果开始日期'Item::product'}
结束
下面是rails控制台的日志
ruby-1.8.7-p334 :020 > item = Item::Item.new
=> #<Item::Item id: nil, start_date: nil, end_date: nil, product_id: nil>
ruby-1.8.7-p334 :021 > item.valid?
NoMethodError: undefined method `<' for nil:NilClass
from /home/maddy/.rvm/gems/ruby-1.8.7-p334/gems/activesupport-3.0.3/lib/active_support/whiny_nil.rb:48:in `method_missing'
from /media/Development/codie/orgstud-security/app/models/lecture/lecture.rb:13:in `validate_start_and_end_date'
from /home/maddy/.rvm/gems/ruby-1.8.7-p334/gems/activesupport-3.0.3/lib/active_support/callbacks.rb:419:in `_run_validate_callbacks'
from /home/maddy/.rvm/gems/ruby-1.8.7-p334/gems/activemodel-3.0.3/lib/active_model/validations.rb:212:in `run_validations!'
from /home/maddy/.rvm/gems/ruby-1.8.7-p334/gems/activemodel-3.0.3/lib/active_model/validations/callbacks.rb:67:in `run_validations!'
from /home/sgarg/.rvm/gems/ruby-1.8.7-p334/gems/activesupport-3.0.3/lib/active_support/callbacks.rb:413:in `_run_validation_callbacks'
from /home/maddy/.rvm/gems/ruby-1.8.7-p334/gems/activemodel-3.0.3/lib/active_model/validations/callbacks.rb:67:in `run_validations!'
from /home/maddy/.rvm/gems/ruby-1.8.7-p334/gems/activemodel-3.0.3/lib/active_model/validations.rb:179:in `valid?'
from /home/maddy/.rvm/gems/ruby-1.8.7-p334/gems/activerecord-3.0.3/lib/active_record/validations.rb:55:in `valid?'
from (irb):21
ruby-1.8.7-p334:020>item=item::item.new
=> #
ruby-1.8.7-p334:021>项。有效吗?
NoMethodError:undefined method`请注意,您在控制台中创建的项
对象的开始日期
,结束日期
等值为零
然后,比较nil导致了异常。请注意,您在控制台中创建的项
对象的开始日期
,结束日期
等均为nil
然后,对验证方法中的nil进行比较会导致异常。这是一种抱怨,因为在进行自定义验证时,尚未设置开始日期和结束日期属性。当它试图比较开始日期和今天的日期时,它试图比较一个nil值
您可以将验证包装在条件块中:
if !start_date.nil? && !end_date.nil?
...
end
这是因为在进行自定义验证时,尚未设置开始日期和结束日期属性。当它试图比较开始日期和今天的日期时,它试图比较一个nil值
您可以将验证包装在条件块中:
if !start_date.nil? && !end_date.nil?
...
end
我刚刚看到第一个代码块描述了touch::touch
模型。你能把Item::Item
模型贴出来吗?(这可能是同一个问题,但我不能确定。)我刚刚看到第一个代码块描述了touch::touch
模型。你能把Item::Item
模型贴出来吗?(可能是同样的问题,但我不能确定。)除非start_date.nil?&&结束日期.nil?
,除非开始日期.nil?&结束日期。无?