I am building a rails engine. I have the following two model classes:
module LandingPageEng
class LandingPage < ActiveRecord::Base
attr_protected # just for debugging right now
has_many :slide_show_images, :dependent => :destroy
accepts_nested_attributes_for :slide_show_images, allow_destroy: true
end
end
The second class is:
module LandingPageEng
class SlideShowImage < ActiveRecord::Base
attr_accessible :image, :landing_page_id
belongs_to :landing_page
validates :image, :presence => true
end
end
The tables associated with them are landing_page_eng_landing_page and landing_page_eng_slide_show_image.
When I run the following in the console I get the error NameError: uninitialized constant SlideShowImage.
1.9.3-p194 :001 > LandingPageEng::LandingPage.new({"title"=>"wd", "tagline"=>"wed", "slide_show_images"=>{"_destroy"=>""}})
NameError: uninitialized constant SlideShowImage
from /Users/martinjlogan/.rvm/gems/ruby-1.9.3-p194/gems/activesupport- 3.2.6/lib/active_support/inflector/methods.rb:229:in `block in constantize'
from /Users/martinjlogan/.rvm/gems/ruby-1.9.3-p194/gems/activesupport-3.2.6/lib/active_support/inflector/methods.rb:228:in `each'
from /Users/martinjlogan/.rvm/gems/ruby-1.9.3-p194/gems/activesupport-3.2.6/lib/active_support/inflector/methods.rb:228:in `constantize'
from /Users/martinjlogan/.rvm/gems/ruby-1.9.3-p194/gems/activesupport-3.2.6/lib/active_support/core_ext/string/inflections.rb:54:in `constantize'
<snip>
I have been banging my head on this and can't figure it out. Any help much appreciated.
I don't have a Rails 3 setup with engines to test this on quickly but I think the issue is with your has_many configuration; it's looking for a class that's named SlideShowImage but your class name is LandingPageEng::SlideShowImage.
I believe adding a :class_name option to your has_many will fix this.
http://railsapi.com/doc/rails-v3.0.8rc1/classes/ActiveRecord/Associations/ClassMethods.html#M004956
Related
I'm trying to make a polymorphic model for my reservations.
A reservation can be from a USER to a ROOM, or from a USER to a MENU.
Those are my classes and migrations.
class Room < ActiveRecord::Base
belongs_to :user
has_many :reservations, as: reservable
class Menu < ActiveRecord::Base
belongs_to :user
has_many :reservations, as: reservable
class Reservation < ActiveRecord::Base
belongs_to :user
belongs_to :reservable, polymorphic: true
end
In my controller I'm trying to access my reservations thru:
def your_trips
#trips = current_user.reservations
end
But I'm getting the error:
NameError in PagesController#home
undefined local variable or method `reservable' for # <Class:0x000000054c8308> Did you mean? reset_table_name
Extracted source (around line #4):
Rails.root: /home/ubuntu/workspace
Application Trace | Framework Trace | Full Trace
app/models/room.rb:4:in `<class:Room>'
app/models/room.rb:1:in `<top (required)>'
app/controllers/pages_controller.rb:3:in `home'
Does anyone have ideas why?
ArgumentError: wrong number of arguments (1 for 0)
from /Users/Castillo/Desktop/gainer/app/models/status.rb:13:in `update_remaining_nutrients'
from /usr/local/rvm/gems/ruby-1.9.3-p392/gems/activerecord-3.2.11/lib/active_record/associations/collection_association.rb:507:in `block in callback'
from /usr/local/rvm/gems/ruby-1.9.3-p392/gems/activerecord-3.2.11/lib/active_record/associations/collection_association.rb:504:in `each'
from /usr/local/rvm/gems/ruby-1.9.3-p392/gems/activerecord-3.2.11/lib/active_record/associations/collection_association.rb:504:in `callback'
from /usr/local/rvm/gems/ruby-1.9.3-p392/gems/activerecord-3.2.11/lib/active_record/associations/collection_association.rb:352:in `add_to_target'
from /usr/local/rvm/gems/ruby-1.9.3-p392/gems/activerecord-3.2.11/lib/active_record/associations/collection_association.rb:495:in `block in concat_records'
from /usr/local/rvm/gems/ruby-1.9.3-p392/gems/activerecord-3.2.11/lib/active_record/associations/collection_association.rb:493:in `each'
from /usr/local/rvm/gems/ruby-1.9.3-p392/gems/activerecord-3.2.11/lib/active_record/associations/collection_association.rb:493:in `concat_records'
from /usr/local/rvm/gems/ruby-1.9.3-p392/gems/activerecord-3.2.11/lib/active_record/associations/collection_association.rb:134:in `block in concat'
from /usr/local/rvm/gems/ruby-1.9.3-p392/gems/activerecord-3.2.11/lib/active_record/associations/collection_association.rb:149:in `block in transaction'
from /usr/local/rvm/gems/ruby-1.9.3-p392/gems/activerecord-3.2.11/lib/active_record/connection_adapters/abstract/database_statements.rb:192:in `transaction'
from /usr/local/rvm/gems/ruby-1.9.3-p392/gems/activerecord-3.2.11/lib/active_record/transactions.rb:208:in `transaction'
from /usr/local/rvm/gems/ruby-1.9.3-p392/gems/activerecord-3.2.11/lib/active_record/associations/collection_association.rb:148:in `transaction'
from /usr/local/rvm/gems/ruby-1.9.3-p392/gems/activerecord-3.2.11/lib/active_record/associations/collection_association.rb:134:in `concat'
from /usr/local/rvm/gems/ruby-1.9.3-p392/gems/activerecord-3.2.11/lib/active_record/associations/collection_proxy.rb:116:in `<<'
from /Users/Castillo/Desktop/gainer/app/models/user.rb:65:in `eat'
from (irb):31
from /usr/local/rvm/gems/ruby-1.9.3-p392/gems/railties-3.2.11/lib/rails/commands/console.rb:47:in `start'
from /usr/local/rvm/gems/ruby-1.9.3-p392/gems/railties-3.2.11/lib/rails/commands/console.rb:8:in `start'
from /usr/local/rvm/gems/ruby-1.9.3-p392/gems/railties-3.2.11/lib/rails/commands.rb:41:in `<top (required)>'
I want to call the update_remaining_nutrients method on status.rb whenever a meal is "eaten" by the user. When I call User.first.eat(Meal.first) I get the ArgumentError. Not sure why because I'm not passing the after_add method any arguments?
user.rb
class User < ActiveRecord::Base
has_many :meals
has_many :statuses
def eat(meal)
statuses.last.meals<<meal
end
end
status.rb
class Status < ActiveRecord::Base
attr_accessible :remaining_calories, :remaining_carbs, :remaining_protein, :weight, :user_id
belongs_to :user
has_many :meals, after_add: :update_remaining_nutrients
after_save :update_users_weight , :if => Proc.new {|a| a.weight_changed?}
def update_users_weight
self.user.weight.update_attributes(weight: self.weight)
end
def update_remaining_nutrients
puts "It Works!!!!!"
end
end
meal.rb
class Meal < ActiveRecord::Base
attr_accessible :name, :description, :clean_up, :homemade, :prep_time, :user_id, :status_id
belongs_to :user
belongs_to :status
has_many :ingredient_meals
has_many :ingredients, :through => :ingredient_meals
end
If you have a look at the Association callbacks section of the docs, you'll see this example:
class Project
has_and_belongs_to_many :developers, after_add: :evaluate_velocity
def evaluate_velocity(developer)
...
end
end
That's not the has_many relationship that you have but it is close enough. If you look at the evaluate_velocity method, you'll see that the developer in question is passed as an argument by the :after_add callback. You're getting an ArgumentError about your update_remaining_nutrients being called with one argument when it doesn't want any and that matches what the the example suggests would happen.
Try this:
def update_remaining_nutrients(meal)
# Do interesting things with `meal` in here...
end
I am trying to add an owner field to DelayedJob. I found this SO answer showing a way to do it
But when I code things up like mentioned in that answer, and in the rails console I do
SomeArModel.new.jobs
I get this error:
NameError: uninitialized constant ActiveRecord::Base::Delayed::Job
The error points to the has_many:
class ActiveRecord::Base
has_many :jobs, :class_name => "Delayed::Job", :as => :owner
....
Any ideas on what is going on here and how I can fix it?
I have two resources that I'm trying to join - Package and Listing through a join table SubmittedPackage. I'm using Ruby 1.9.3-p125 and Rails 3.2.1 with PostgreSQL 9.1.3. The models look as follows.
class Package < ActiveRecord::Base
has_many :submitted_packages
has_many :listings, :through => :submitted_packages
class Listing < ActiveRecord::Base
has_many :submitted_packages
has_many :packages, :through => :submitted_packages
class SubmittedPackages < ActiveRecord::Base
belongs_to :package
belongs_to :listing
In Rails Console I keep getting NameError: uninitialized constant Listing::SubmittedPackage
If I replace the SubmittedPackage resource with Drum it will work (this of course includes having the appropriate table created and so forth).
Is :submitted_packages in conflict with something in Rails or ActiveRecord?
Any ideas why this is breaking?
Thanks in advance!
UPDATE: As a work-around I explicitly defined the :class_name for the has many relationship in the Listing and Package model. This has at least gotten things working, however, it's still is unclear to me why it was necessary to begin with. What Rails or Ruby naming convention was being broken by :submitted_packages ?
class Package < ActiveRecord::Base
has_many :submitted_packages, :class_name => 'SubmittedPackages'
has_many :listings, :through => :submitted_packages
class Listing < ActiveRecord::Base
has_many :submitted_packages, :class_name => 'SubmittedPackages'
has_many :packages, :through => :submitted_packages
class SubmittedPackages < ActiveRecord::Base
belongs_to :package
belongs_to :listing
If SubmittedPackage is the JoinTable, I guess it should have many listings, but I'm seeing just many packages and many submitted_packages.
HTH
I am playing around with an Example on testing a has_many through association in RSpec.
I am getting a
1) Foo specifies items
Failure/Error: subject.should have_many(:items)
NoMethodError:
undefined method `has_many?' for #
# ./spec/models/foo_spec.rb:10
My question: Why would has_many be undefined?
The spec is:
describe Foo do
it "specifies items" do
subject.should have_many(:items)
end
end
My models are:
foo.rb:
class Foo < ActiveRecord::Base
has_many :bars
has_many :items, :through => :bars
end
bar.rb:
class Bar < ActiveRecord::Base
belongs_to :foo
belongs_to :item
end
and item.rb:
class Item < ActiveRecord::Base
has_many :foos, :through => :bars
has_many :bars
end
Well, there is no has_many? method on model objects. And rspec-rails does not provide such matcher by default. However, shoulda-matchers gem does:
describe Post do
it { should belong_to(:user) }
it { should have_many(:tags).through(:taggings) }
end
describe User do
it { should have_many(:posts) }
end
(example from shoulda-matchers documentation)
Just add gem 'shoulda-matchers' to your Gemfile and you will be able to use that syntax.