has_may for a vote app - ruby-on-rails

Question

I'm new on rails and I'm trying to make my own simple vote application. I have two models:
class Product < ActiveRecord::Base
attr_accessible :description, :title, :photo
has_many :votes
has_attached_file :photo, :styles => { :medium => "300x300" }
before_save { |product| product.title = title.titlecase }
validates :title, presence: true, uniqueness: { case_sensitive: false }
validates :photo, :attachment_presence => true
end
class Vote < ActiveRecord::Base
belongs_to :product
attr_accessible :user_id
end
here is the product controller
class ProductsController < ApplicationController
http_basic_authenticate_with :name => "dhh", :password => "secret", :except => [:index]
def index
#products = Product.all
end
def indexprv
#products = Product.all
end
def show
#product = Product.find(params[:id])
end
def edit
#product = Product.find(params[:id])
end
def new
#product = Product.new
end
def create
#product = Product.new(params[:product])
if #product.save
redirect_to #product
else
render 'new'
end
end
def update
#product = Product.find(params[:id])
if #product.update_attributes(params[:product])
flash[:success] = "Producto Actualizado"
redirect_to root_path
else
render 'edit'
end
end
def destroy
Product.find(params[:id]).destroy
flash[:success] = "Producto Eliminado."
redirect_to root_path
end
end
I have many questions.
How can I show the total votes per products on my index page of products?
How can I create a button on my index product page to add a vote for a product?
I don't know how to do this and I couldn't find any tutorial o blog with a similar example.
Thanks for your help.

Answer 1

Your index view probably already loops through every product you have (either by a partial or by a loop). In your loop/partial do something like: (assuming the variable product has a instance of a product)
product.votes.count
to get the number of votes. To get a button to add a vote do something along the lines of:
link_to "Add Vote", new_product_vote_path(product), action: :new
A good tutorial that covers many aspects of rails is: http://ruby.railstutorial.org/chapters/beginning#top
Edit:
Your index method in your controller gives you an array of every product you have. So if you do something like this in your index view (if your using erb):
<ul>
<% #products.each do |product| %>
<li>
<%= product.title %>: <br />
Votes: <%= product.votes.count %> <br />
<%= link_to "Add Vote", new_product_vote_path(product), action: :new %>
</li>
<% end %>
</ul>
it should do what you want