8.3 Iteration C2: A Smarter Cart posted by osagie uwaifo @ Wed, 21 May 2008 01:48:10 -0000

osagie uwaifo — Wed, 21 May 2008 01:48:10 -0000

I just wanted to say thanks Sam for your guidance. It worked just fine. I really don’t know were i got this line from :@items << product. Thanks a lot.

8.3 Iteration C2: A Smarter Cart posted by osagie uwaifo @ Tue, 20 May 2008 21:34:25 -0000

osagie uwaifo — Tue, 20 May 2008 21:34:25 -0000

Thanks a lot. I will try the code above and let you know if it works.

8.3 Iteration C2: A Smarter Cart posted by Sam Ruby @ Tue, 20 May 2008 20:57:13 -0000

Sam Ruby — Tue, 20 May 2008 20:57:13 -0000

It looks to me like your add_produce method does nothing… it immediately is followed by an end instead of actually containing the following code. The app/models/cart.rb is supposed to look something like this:

class Cart
  attr_reader :items

  def initialize
    @items = []
  end

  def add_product(product)
    current_item = @items.find {|item| item.product == product}
    if current_item
      current_item.increment_quantity
    else
      @items << CartItem.new(product)
    end
  end

  def total_price
    @items.sum { |item| item.price }
  end

end

8.3 Iteration C2: A Smarter Cart posted by osagie uwaifo @ Tue, 20 May 2008 18:25:15 -0000

osagie uwaifo — Tue, 20 May 2008 18:25:15 -0000

It is still creating product object. And actually seems right to me. when the add product method is called, we are passing in a product object. The we add the product object to the @items array.

current_item = @items.find {|item| item.product == product}

From the line above we do try to call a method item.product that really does not exist. This seems right.

I think there should be a better way of writing this method. Please let me know what you think. Thanks for your time.

8.3 Iteration C2: A Smarter Cart posted by osagie uwaifo @ Tue, 20 May 2008 18:16:29 -0000

osagie uwaifo — Tue, 20 May 2008 18:16:29 -0000

This is my Cart class

class Cart

attr_reader :items , :quantity# <whatis linkend="wtf.attr.accessor">attr_reader</whatis>TRUNC

def initialize
    @items = []
end

def add_product(product)
end

@items << product
puts @items

current_item = @items.find {|item| item.product == product}
puts "printing current_item " +current_item
if current_item
    current_item.increment_quantity
else
end

@items << CartItem.new(product)

def total_price
    @items.sum { |item| item.price }
end

end

8.3 Iteration C2: A Smarter Cart posted by osagie uwaifo @ Tue, 20 May 2008 15:17:07 -0000

osagie uwaifo — Tue, 20 May 2008 15:17:07 -0000

Thank you for your quick response. I will try that and see what happens.

8.3 Iteration C2: A Smarter Cart posted by Sam Ruby @ Tue, 20 May 2008 10:52:04 -0000

Sam Ruby — Tue, 20 May 2008 10:52:04 -0000

The error you are describing sounds suspiciously like the error described on page 111 of B1.1. The solution described there is to issue the command:

rake db:sessions:clear

If you are still seeing product objects in your @items array, I would like to see your add_product method implementation from app/models/cart.rb.

8.3 Iteration C2: A Smarter Cart posted by osagie uwaifo @ Tue, 20 May 2008 04:21:57 -0000

osagie uwaifo — Tue, 20 May 2008 04:21:57 -0000

Hi i can’t get passed this section. I have read and tried everything on the forums. I keep getting this error:

NoMethodError in StoreController#add_to_cart

undefined method `product’ for #<product:0x368b354>

RAILS_ROOT: C:/Rails/rails_apps/depot
Application Trace | Framework Trace | Full Trace

c:/ruby/lib/ruby/gems/1.8/gems/activerecord-2.0.2-/lib/active_record/attribute_methods.rb:205:in `method_missing’
app/models/cart.rb:16:in `add_product’
app/models/cart.rb:16:in `each’
app/models/cart.rb:16:in `find’
app/models/cart.rb:16:in `add_product’
app/controllers/store_controller.rb:19:in `add_to_cart’

c:/ruby/lib/ruby/gems/1.8/gems/activerecord-2.0.2-/lib/active_record/attribute_methods.rb:205:in `method_missing’
c:/ruby/lib/ruby/gems/1.8/gems/activerecord-2.0.2-/lib/active_record/base.rb:1602:in `find’
c:/ruby/lib/ruby/gems/1.8/gems/actionpack-2.0.2/lib/action_controller/base.rb:1158:in `send’
c:/ruby/lib/ruby/gems/1.8/gems/actionpack-2.0.2/lib/action_controller/base.rb:1158:in `perform_action_without_filters’
c:/ruby/lib/ruby/gems/1.8/gems/actionpack-2.0.2/lib/action_controller/filters.rb:697:in `call_filters’
c:/ruby/lib/ruby/gems/1.8/gems/actionpack-2.0.2/lib/action_controller/filters.rb:689:in `perform_action_without_benchmark’
c:/ruby/lib/ruby/gems/1.8/gems/actionpack-2.0.2/lib/action_controller/benchmarking.rb:68:in `perform_action_without_rescue’
c:/ruby/lib/ruby/1.8/benchmark.rb:293:in `measure’
c:/ruby/lib/ruby/gems/1.8/gems/actionpack-2.0.2/lib/action_controller/benchmarking.rb:68:in `perform_action_without_rescue’
c:/ruby/lib/ruby/gems/1.8/gems/actionpack-2.0.2/lib/action_controller/rescue.rb:199:in `perform_action_without_caching’
c:/ruby/lib/ruby/gems/1.8/gems/actionpack-2.0.2/lib/action_controller/caching.rb:678:in `perform_action’
c:/ruby/lib/ruby/gems/1.8/gems/activerecord-2.0.2-/lib/active_record/connection_adapters/abstract/query_cache.rb:33:in `cache’
c:/ruby/lib/ruby/gems/1.8/gems/activerecord-2.0.2-/lib/active_record/query_cache.rb:8:in `cache’
c:/ruby/lib/ruby/gems/1.8/gems/actionpack-2.0.2/lib/action_controller/caching.rb:677:in `perform_action’
c:/ruby/lib/ruby/gems/1.8/gems/actionpack-2.0.2/lib/action_controller/base.rb:524:in `send’
c:/ruby/lib/ruby/gems/1.8/gems/actionpack-2.0.2/lib/action_controller/base.rb:524:in `process_without_filters’
c:/ruby/lib/ruby/gems/1.8/gems/actionpack-2.0.2/lib/action_controller/filters.rb:685:in `process_without_session_management_support’
c:/ruby/lib/ruby/gems/1.8/gems/actionpack-2.0.2/lib/action_controller/session_management.rb:123:in `process’
c:/ruby/lib/ruby/gems/1.8/gems/actionpack-2.0.2/lib/action_controller/base.rb:388:in `process’
c:/ruby/lib/ruby/gems/1.8/gems/actionpack-2.0.2/lib/action_controller/dispatcher.rb:171:in `handle_request’
c:/ruby/lib/ruby/gems/1.8/gems/actionpack-2.0.2/lib/action_controller/dispatcher.rb:115:in `dispatch’
c:/ruby/lib/ruby/gems/1.8/gems/actionpack-2.0.2/lib/action_controller/dispatcher.rb:126:in `dispatch_cgi’
c:/ruby/lib/ruby/gems/1.8/gems/actionpack-2.0.2/lib/action_controller/dispatcher.rb:9:in `dispatch’
c:/ruby/lib/ruby/gems/1.8/gems/rails-2.0.2-/lib/webrick_server.rb:112:in `handle_dispatch’
c:/ruby/lib/ruby/gems/1.8/gems/rails-2.0.2-/lib/webrick_server.rb:78:in `service’
c:/ruby/lib/ruby/1.8/webrick/httpserver.rb:104:in `service’
c:/ruby/lib/ruby/1.8/webrick/httpserver.rb:65:in `run’
c:/ruby/lib/ruby/1.8/webrick/server.rb:173:in `start_thread’
c:/ruby/lib/ruby/1.8/webrick/server.rb:162:in `start’
c:/ruby/lib/ruby/1.8/webrick/server.rb:162:in `start_thread’
c:/ruby/lib/ruby/1.8/webrick/server.rb:95:in `start’
c:/ruby/lib/ruby/1.8/webrick/server.rb:92:in `each’
c:/ruby/lib/ruby/1.8/webrick/server.rb:92:in `start’
c:/ruby/lib/ruby/1.8/webrick/server.rb:23:in `start’
c:/ruby/lib/ruby/1.8/webrick/server.rb:82:in `start’
c:/ruby/lib/ruby/gems/1.8/gems/rails-2.0.2-/lib/webrick_server.rb:62:in `dispatch’
c:/ruby/lib/ruby/gems/1.8/gems/rails-2.0.2-/lib/commands/servers/webrick.rb:66
c:/ruby/lib/ruby/site_ruby/1.8/rubygems/custom_require.rb:27:in `gem_original_require’
c:/ruby/lib/ruby/site_ruby/1.8/rubygems/custom_require.rb:27:in `require’
c:/ruby/lib/ruby/gems/1.8/gems/activesupport-2.0.2-/lib/active_support/dependencies.rb:496:in `require’
c:/ruby/lib/ruby/gems/1.8/gems/activesupport-2.0.2-/lib/active_support/dependencies.rb:342:in `new_constants_in’
c:/ruby/lib/ruby/gems/1.8/gems/activesupport-2.0.2-/lib/active_support/dependencies.rb:496:in `require’
c:/ruby/lib/ruby/gems/1.8/gems/rails-2.0.2-/lib/commands/server.rb:39
c:/ruby/lib/ruby/site_ruby/1.8/rubygems/custom_require.rb:27:in `gem_original_require’
c:/ruby/lib/ruby/site_ruby/1.8/rubygems/custom_require.rb:27:in `require’
script/server:3

c:/ruby/lib/ruby/gems/1.8/gems/activerecord-2.0.2-/lib/active_record/attribute_methods.rb:205:in `method_missing’
app/models/cart.rb:16:in `add_product’
c:/ruby/lib/ruby/gems/1.8/gems/activerecord-2.0.2-/lib/active_record/base.rb:1602:in `find’
app/models/cart.rb:16:in `each’
app/models/cart.rb:16:in `find’
app/models/cart.rb:16:in `add_product’
app/controllers/store_controller.rb:19:in `add_to_cart’
c:/ruby/lib/ruby/gems/1.8/gems/actionpack-2.0.2/lib/action_controller/base.rb:1158:in `send’
c:/ruby/lib/ruby/gems/1.8/gems/actionpack-2.0.2/lib/action_controller/base.rb:1158:in `perform_action_without_filters’
c:/ruby/lib/ruby/gems/1.8/gems/actionpack-2.0.2/lib/action_controller/filters.rb:697:in `call_filters’
c:/ruby/lib/ruby/gems/1.8/gems/actionpack-2.0.2/lib/action_controller/filters.rb:689:in `perform_action_without_benchmark’
c:/ruby/lib/ruby/gems/1.8/gems/actionpack-2.0.2/lib/action_controller/benchmarking.rb:68:in `perform_action_without_rescue’
c:/ruby/lib/ruby/1.8/benchmark.rb:293:in `measure’
c:/ruby/lib/ruby/gems/1.8/gems/actionpack-2.0.2/lib/action_controller/benchmarking.rb:68:in `perform_action_without_rescue’
c:/ruby/lib/ruby/gems/1.8/gems/actionpack-2.0.2/lib/action_controller/rescue.rb:199:in `perform_action_without_caching’
c:/ruby/lib/ruby/gems/1.8/gems/actionpack-2.0.2/lib/action_controller/caching.rb:678:in `perform_action’
c:/ruby/lib/ruby/gems/1.8/gems/activerecord-2.0.2-/lib/active_record/connection_adapters/abstract/query_cache.rb:33:in `cache’
c:/ruby/lib/ruby/gems/1.8/gems/activerecord-2.0.2-/lib/active_record/query_cache.rb:8:in `cache’
c:/ruby/lib/ruby/gems/1.8/gems/actionpack-2.0.2/lib/action_controller/caching.rb:677:in `perform_action’
c:/ruby/lib/ruby/gems/1.8/gems/actionpack-2.0.2/lib/action_controller/base.rb:524:in `send’
c:/ruby/lib/ruby/gems/1.8/gems/actionpack-2.0.2/lib/action_controller/base.rb:524:in `process_without_filters’
c:/ruby/lib/ruby/gems/1.8/gems/actionpack-2.0.2/lib/action_controller/filters.rb:685:in `process_without_session_management_support’
c:/ruby/lib/ruby/gems/1.8/gems/actionpack-2.0.2/lib/action_controller/session_management.rb:123:in `process’
c:/ruby/lib/ruby/gems/1.8/gems/actionpack-2.0.2/lib/action_controller/base.rb:388:in `process’
c:/ruby/lib/ruby/gems/1.8/gems/actionpack-2.0.2/lib/action_controller/dispatcher.rb:171:in `handle_request’
c:/ruby/lib/ruby/gems/1.8/gems/actionpack-2.0.2/lib/action_controller/dispatcher.rb:115:in `dispatch’
c:/ruby/lib/ruby/gems/1.8/gems/actionpack-2.0.2/lib/action_controller/dispatcher.rb:126:in `dispatch_cgi’
c:/ruby/lib/ruby/gems/1.8/gems/actionpack-2.0.2/lib/action_controller/dispatcher.rb:9:in `dispatch’
c:/ruby/lib/ruby/gems/1.8/gems/rails-2.0.2-/lib/webrick_server.rb:112:in `handle_dispatch’
c:/ruby/lib/ruby/gems/1.8/gems/rails-2.0.2-/lib/webrick_server.rb:78:in `service’
c:/ruby/lib/ruby/1.8/webrick/httpserver.rb:104:in `service’
c:/ruby/lib/ruby/1.8/webrick/httpserver.rb:65:in `run’
c:/ruby/lib/ruby/1.8/webrick/server.rb:173:in `start_thread’
c:/ruby/lib/ruby/1.8/webrick/server.rb:162:in `start’
c:/ruby/lib/ruby/1.8/webrick/server.rb:162:in `start_thread’
c:/ruby/lib/ruby/1.8/webrick/server.rb:95:in `start’
c:/ruby/lib/ruby/1.8/webrick/server.rb:92:in `each’
c:/ruby/lib/ruby/1.8/webrick/server.rb:92:in `start’
c:/ruby/lib/ruby/1.8/webrick/server.rb:23:in `start’
c:/ruby/lib/ruby/1.8/webrick/server.rb:82:in `start’
c:/ruby/lib/ruby/gems/1.8/gems/rails-2.0.2-/lib/webrick_server.rb:62:in `dispatch’
c:/ruby/lib/ruby/gems/1.8/gems/rails-2.0.2-/lib/commands/servers/webrick.rb:66
c:/ruby/lib/ruby/site_ruby/1.8/rubygems/custom_require.rb:27:in `gem_original_require’
c:/ruby/lib/ruby/site_ruby/1.8/rubygems/custom_require.rb:27:in `require’
c:/ruby/lib/ruby/gems/1.8/gems/activesupport-2.0.2-/lib/active_support/dependencies.rb:496:in `require’
c:/ruby/lib/ruby/gems/1.8/gems/activesupport-2.0.2-/lib/active_support/dependencies.rb:342:in `new_constants_in’
c:/ruby/lib/ruby/gems/1.8/gems/activesupport-2.0.2-/lib/active_support/dependencies.rb:496:in `require’
c:/ruby/lib/ruby/gems/1.8/gems/rails-2.0.2-/lib/commands/server.rb:39
c:/ruby/lib/ruby/site_ruby/1.8/rubygems/custom_require.rb:27:in `gem_original_require’
c:/ruby/lib/ruby/site_ruby/1.8/rubygems/custom_require.rb:27:in `require’
script/server:3

Request

Parameters:

{“authenticity_token”=>”d3f613dc201329a40d6e9cf91e9528e242c96fc9”, “id”=>”1”}

Sorry i copied everything. Basically, it is not finding anything with the CartItem class. The application thinks i am calling the product object. It is not recognizing the cartItem class at all. I have deleted/dropped my database and ran rake db:migrate command again to populate my database again. I am using SQLite3. I am wondering how the cart class is talking to the cartItem class since there is no require ’’ statement in either of the file. And also how the product is actually able to see these files.

This is my controller class
class StoreController < ApplicationController

attr_reader :product

def index
    @products = Product.find_products_for_sale
end

public
def add_to_cart

product = Product.find(params[:id])

@cart = find_cart
@cart.add_product(product)

end

private
def find_cart
    unless session[:cart] # if there's no cart in the session
           session[:cart] = Cart.new # add a new one
    end
           session[:cart] # return existing or new cart
end
end

Basically, I need the application to recognize the CartItem class, if anyone can point me to the right path, i will appreciate it.

I think the error is from this line in the cart class :
current_item = @items.find {|item| item.product == product}

It is returning a product type or a product type object. Basically, cartItem objects and product objects are being stored in the items array.
This code is a little confusing. This line is what is holding me back. I know this becos i put a puts statement after this line and it does not reach my print statement.
Any help would be appreciated.

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