nomethoderror

I'm learning Rails following the book Agile Web Development with Rails 4 and I got stuck with this Error: NoMethodError in CartsController#destroy undefined method `name' for nil:NilClass This is the action Destroy of the Cart controller. The error info references to the line @cart.destroy if @cart.id == session[:cart_id] : # DELETE /carts/1 # DELETE /carts/1.json def destroy @cart.destroy if @cart.id == session[:cart_id] session[:cart_id] = nil respond_to do |format| format.html { redirect_to store_url, notice: 'Your cart is currently empty'} format.json { head :no_content } end end This

I am trying to follow this coderwall tutorial about Creating a Scoped Invitation System for Rails . In my Rails 4 app, I have the following models: class User < ActiveRecord::Base has_many :administrations has_many :calendars, through: :administrations has_many :invitations, :class_name => "Invite", :foreign_key => 'recipient_id' has_many :sent_invites, :class_name => "Invite", :foreign_key => 'sender_id' end class Calendar < ActiveRecord::Base has_many :administrations has_many :users, through: :administrations has_many :invites end class Administration < ActiveRecord::Base belongs_to :user

I keep getting the following error message: text.rb:2:in `<main>': undefined method `choices' for main:Object (NoMethodError) But I can't seem to understand why my method is "undefined": puts "Select [1] [2] [3] or [q] to quit"; users_choice = gets.chomp choices(users_choice) def choices (choice) while choice != 'q' case choice when '1' puts "you chose one!" when '2' puts "you chose two!" when '3' puts "you chose three!" end end end This is because you are calling method choices , before defining it. Write the code as below: puts "Select [1] [2] [3] or [q] to quit" users_choice = gets.chomp

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 /Users/me/.rvm/gems/ruby-1.9.2-p180/gems/railties-3.0.10/lib/rails/commands/console.rb:44:in `start'

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: defaultReader at com.jayway.jsonpath.spi.json.JsonSmartJsonProvider.<init>(JsonSmartJsonProvider.java:39) at com

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): actionpack (3.2.1) lib/action_controller/metal/hide_actions.rb:36:in `visible_action?' actionpack (3.2.1) lib