Question

I have a shop application and another site thats for a special promotion. I’ve used Active Resource to import products from the shop in to the promo site and added a shopping cart to add the products. However, to actually order the products I need to send the items to the shop application, creating a new cart there to finish the order.

I’ve made a demo ‘RESTful’ application to practice using xml to send data back and forth, so I’m trying to use the principles of REST for the real app. However, I need to send the products to a non-RESTful controller. Just to give you an idea of the Cart controller in the shop, here are its actions:

def index…
def add…
def checkout…
def update…
def remove…
def empty…
def apply_discount…
def remove_discount…
def apply_credits…
def remove_credits…
def stock_check…

# My action to accept items from carts in other apps
def cart_import…

And in routes.rb, the only route relating to the cart is currently

  map.cart              'cart/:action/:id',       :controller => 'shop/cart'

I’ve inherited the shop application from a previous developer, so I’d probably try to make it more RESTful if I was to make it from scratch.

Anyway, I’m pretty confident that I can get the cart to respond to XML, even without being defined with map.resources. My problem is how to send a hash of the cart items and quantities from the promo app.

To group the cart items and quantities I’ve collected the item’s product id and quantity in to a hash:

<% @items = Hash.new %>
<% @cart.items.collect {|i| @items[i.product_id] = i.quantity} %>

Which when inspected gives the following output:

<%= Rails.logger.info @items.inspect %>
{1144=>2, 1143=>1}

So I figured to send them to the shop I could pass them in a posted link_to:

<%= link_to 'Export Cart', "http://shop.example.com/cart/cart_import", :items => @items, :method => :post %>

That doesn’t seem to do anything, whereas omitting the first field appends the items to the URL in a format that looks sensible, but appears as a relative link on the promo application:

<%= link_to "http://shop.example.com/cart/cart_import", :items => @items, :method => :post %>

http://promo.example.com/cart?items%5B1143%5D=1&items%5B1144%5D=2&method=post

I’m sure the clue is in that the @items object needs to be passed in with the url, but since I can’t use a named route I don’t really know how to get it in there so that it is posted in the correct format.

Thanks for the help,

Gareth

Answer 1

In the end I made a helper:

def hash_to_params(items)
  result = ""
   i = 0
   items.each do |item|
     i > 0 ? result += "&" : result += ""
     result += "items[#{item[0]}]=#{item[1]}"
     i += 1
   end
  return result
end

Then for the link I called the helper:

<%= link_to "export", "http://shop.example.com/cart/cart_import?#{hash_to_params(@items)}", :method => :post %>

Pretty ugly way of doing it, but I really can’t think of anything better?

Cheers,

Gareth