Question

I need help on figuring how to make a link for my Product that enables users to subscribe to it. I first have my Subscription model:

class Subscription < ActiveRecord::Base
  attr_accessible :subscribable_id
  belongs_to :subscriber, :class_name => "User"
  belongs_to :subscribable, :polymorphic => true
end

Then my Product model:

class Product < ActiveRecord::Base
  attr_accessible :name, :price
  belongs_to :user
  has_many :subscriptions, :as => :subscribable
end

My plan is to make my view, similar to the DELETE method a link to click to subscribe to a product. Here is my routes, controller and then view:

resources :products do
    post :subscribe_product, :on => :collection
end

ProductsController:

def subscribe_product
  @product = Product.find(params[:id])
  # Not sure what goes here next? 
  # Something like: user.subscriptions.create(:subscribable => product)
end

View:

<table>
 <% for product in @products %>
  <tbody>
   <tr>
    <td><%= product.name %></td>
    <td><%= product.price %></td>
    <td><%= link_to 'Delete', product, :confirm => 'Are you sure?', :method => :delete %></td>
    <td><%= link_to 'Subscribe', :controller => "products", :action => "subscribe_product", :id => product.id %></td>
   </tr>
  </tbody>
 <% end %>
</table>

Right now this gives a strange error:

ActiveRecord::RecordNotFound in ProductsController#show

Couldn't find Product with id=subscribe_product

Theirs 2 things,

1. Creating the method to subscribe.
2. Making the link correct.

How would I do these two?

Answer 1

Your subscribe_product path uses POST, so you’ll want to change your link to use that method:

<%= link_to 'Subscribe', {:controller => "products", :action => "subscribe_product", :id => product.id}, :method => :post %>

Your action will probably look something like this:

@product.subscriptions << Subscription.new(:user_id => current_user.id)