Rotating product of the day in Rails

Question

Hi all-

I am creating a site similar to the infamous Woot in one particular way: I would like to rotate through products at a rate of one per day. I am using RoR, and would prefer to dynamically choose a product, and not have to enter one each day. So here are the requirements:

1) Get a new product each day
2) Select dynamically from a table
3) Make sure not to select the same product twice

Thats about it. In the products table, I currently have a boolean called listed which will mark if the product has been listed. My question is, should I run some kind of database job to choose a product for that day or is there some way I can like hash the date and come up with an id that the app will display until the date changes.

Thanks for the time.

Answer 1

Personally, I would keep it simple and go the scheduled job approach. To be more specific, I'd probably use the whenever gem to wrap a cron-job that runs once daily at midnight. You can then set up a method in your Product model to select the current 'Product of the Day'.

Something like this should work:

product.rb

class Product < ActiveRecord::Base
  # Return the current product of the day
  def self.product_of_the_day
    self.find_by_listed(true)
  end

  # Set up the product of the day
  def self.setup_product_of_the_day
    current_product = self.product_of_the_day

    product_ids = self.all(
      :select => "id",
      :conditions => ['id != ?', current_product.id]
    )

    next_product = self.find(product_ids[rand(product_ids.length)])

    current_product.update_attribute(:listed, false)
    next_product.update_attribute(:listed, true)
  end
end

schedule.rb

every 1.day do
  runner "Product.setup_product_of_the_day"
end