Adding items to a cart redirecting wrong - ruby-on-rails

Question

I've been following this Railscast on implementing Active Merchant in a new test app and it was going well, but now that I'm trying to add what I made to my main app its breaking.
When clicking 'add to cart' on my test app, it redirects to the current cart and lists the item as expected.
On my main app clicking the add to cart link redirects to:
http://mainapp.dev/line_items?product_id=1
The line_items controller looks like this:
class LineItemsController < ApplicationController
def create
#product = Product.find(params[:product_id])
#line_item = LineItem.create!(:cart => current_cart, :product => #product, :quantity => 1, :unit_price => #product.price)
flash[:notice] = "Added #{#product.name} to cart."
redirect_to current_cart_url
end
end
The add to cart link looks like this:
<%= link_to "Add to Cart", line_items_path(:product_id => product), :method => :post, :class => "product_actions" %>
edit - logs
Test version on adding an item (working):
Started POST "/line_items?product_id=5" for 127.0.0.1 at 2011-09-01 07:33:27 +0100
Processing by LineItemsController#create as HTML
Parameters: {"authenticity_token"=>"li7gkjksc9MENevuGz7emDwnbB6HrvPAE3CY=", "product_id"=>"5"}
[1m[35mProduct Load (0.4ms)[0m SELECT `products`.* FROM `products` WHERE `products`.`id` = 5 LIMIT 1
[1m[36m (33.1ms)[0m [1mBEGIN[0m
[1m[35mSQL (179.4ms)[0m INSERT INTO `carts` (`created_at`, `purchased_at`, `updated_at`) VALUES ('2011-09-01 06:33:28', NULL, '2011-09-01 06:33:28')
[1m[36m (48.3ms)[0m [1mCOMMIT[0m
[1m[35m (0.2ms)[0m BEGIN
[1m[36mSQL (0.2ms)[0m [1mINSERT INTO `line_items` (`cart_id`, `created_at`, `product_id`, `quantity`, `unit_price`, `updated_at`) VALUES (29, '2011-09-01 06:33:29', 5, 1, 250, '2011-09-01 06:33:29')[0m
[1m[35m (0.5ms)[0m COMMIT
Redirected to http://sell.dev/cart
Completed 302 Found in 1265ms
Started GET "/cart" for 127.0.0.1 at 2011-09-01 07:33:29 +0100
Processing by CartsController#show as HTML
[1m[36mCart Load (0.2ms)[0m [1mSELECT `carts`.* FROM `carts` WHERE `carts`.`id` = 29 LIMIT 1[0m
[1m[35mLineItem Load (0.3ms)[0m SELECT `line_items`.* FROM `line_items` WHERE `line_items`.`cart_id` = 29
[1m[36mProduct Load (0.5ms)[0m [1mSELECT `products`.* FROM `products` WHERE `products`.`id` = 5 LIMIT 1[0m
Rendered carts/show.html.erb within layouts/application (202.1ms)
Rendered layouts/_header.html.erb (0.8ms)
Rendered layouts/_footer.html.erb (0.7ms)
Completed 200 OK in 368ms (Views: 284.2ms | ActiveRecord: 79.5ms)
The main app version:
Started GET "/line_items?product_id=1" for 127.0.0.1 at 2011-09-01 07:34:59 +0100
Processing by LineItemsController#index as HTML
Parameters: {"product_id"=>"1"}
Rendered line_items/index.html.erb within layouts/application (0.3ms)
Rendered layouts/_header.html.erb (1.3ms)
Rendered layouts/_footer.html.erb (178.4ms)
Completed 200 OK in 218ms (Views: 182.3ms | ActiveRecord: 35.5ms)
I can't figure out why it's wanting to redirect to the line items index and not create, the code is the same.
edit - routes
get "cart" => "carts#show", :as => "current_cart"
resources :orders
resources :line_items
resources :carts
resources :products
resources :order_transactions
edit - taken from my application controller
def current_user
#current_user ||= User.find(session[:user_id]) if session[:user_id]
end
def current_cart
if session[:cart_id]
#current_cart ||= Cart.find(session[:cart_id])
session[:cart_id] = nil if #current_cart.purchased_at
end
if session[:cart_id].nil?
#current_cart = Cart.create!
session[:cart_id] = #current_cart.id
end
#current_cart
end
Thanks for any help its much appreciated!

Answer 1

If you add an item to your cart by clicking on the link "Add to cart" then you will need to call the create action in the LineItemsController controller as you have it now.
The last line of that method is
redirect_to current_cart_url
So you are indeed redirecting to the current_cart as you want but you are saying you are not redirecting to the current cart which is nonsense really.
Perhaps you have not yet set up the current_cart_url path or views or something?
I'm am not clear on what your actual problem is
Started GET "/line_items?product_id=1" for 127.0.0.1 at 2011-09-01 07:34:59 +0100
Processing by LineItemsController#index as HTML
Parameters: {"product_id"=>"1"}
Rendered line_items/index.html.erb within layouts/application (0.3ms)
Rendered layouts/_header.html.erb (1.3ms)
Rendered layouts/_footer.html.erb (178.4ms)
Completed 200 OK in 218ms (Views: 182.3ms | ActiveRecord: 35.5ms)
There MUST be something happening after this! ~What is it?
edit - solution
Sorry, I totally missed the obvious.
<%= link_to "Add to Cart", line_items_path(:product_id => product), :method => :post, :class => "product_actions" %>
is issuing a get request NOT a post request as indicated by your log file Started GET "/cart" for 127.0.0.1 at 2011-09-01 07:33:29 +0100
You are adding an item to the cart which means you are changing state on the server which means you should be using a POST request NOT a get (link) request and therefore you should use a form (button_to will give you that form). Unless you want loads of bot's spiders;/crawlers etc... adding stuff to your cart you should use
<%= button_to 'Add to Cart', line_items_path(:product_id => product) %>