nomethoderror

问题 Here is my code: class Order < Grape::Entity expose :id { |order, options| order.id.obfuscate } expose :time_left_to_review do |order, options| byebug order&.time_left_to_review # ERROR end expose :created_at { |order, options| order.last_transition.created_at } end # NoMethodError Exception: undefined method `time_left_to_review' for #<Order:0x007f83b9efc970> I thought &. is a shortcut for .try but I guess I was wrong. May someone point me to the right direction regarding what I am missing?

问题 Why is try throwing an error? Doesnt that defeat the whole purpose? Maybe its just in the console? ruby-1.9.2-p180 :101 > User.first.try(:something) NoMethodError: undefined method `something' for #<User:0x000001046ad128> from /Users/me/.rvm/gems/ruby-1.9.2-p180/gems/activemodel-3.0.10/lib/active_model/attribute_methods.rb:392:in `method_missing' from /Users/me/.rvm/gems/ruby-1.9.2-p180/gems/activerecord-3.0.10/lib/active_record/attribute_methods.rb:46:in `method_missing' from (irb):101 from

问题 I am using a JSON parser to extract the value and I am using the following jar json-path-2.1.0, and I am getting the following error when I invoke the use case deployed as webservice on weblogic server I wrote a small main program to extract the value from the json string and it works fine, but the server version of the use case is giving the issue. I am not sure if there are any other jars part of my ear can negatively impact this SEVERE: defaultReader java.lang.NoSuchFieldError:

问题 For some reason I started to get this error after switching to Rails 3.2. I guess it has something to do with acl9 plugin, which I tried reinstalling, but nothing changed. I moved the plugins to lib/plugins and added initializer to config/initializers but again, same error. I looked for solution at acl9 repo on Github, but could not find anything there. Maybe it is not acl9 after all. I have paperclip, acl9, authlogic installed. NoMethodError (undefined method `key?' for nil:NilClass):