getting a random product in rails - ruby-on-rails

Question

/products/index.html.erb
<div class="hide-for-small panel">
<h3>Sidebar</h3>
<h5 class="subheader">Feature Product</h5>
<% Product.random do | product | %>
<%= image_tag(Product.image_url) %>
<h5><%= link_to Product.title, product %></h5>
<p><%= button_to 'Add to Cart', line_items_path(:product_id => product) %></p>
<% end %>
</div>
/models/product.rb
def Product.random
self.limit(1).offset(rand(self.count)).first
end
Trying to pull a random product using Postgres. The query comes through in the console but I get no view results in the index.
Any solutions or different ways of accomplishing this?

Answer 1

The whole issue is you're passing a block to a method that doesn't take a block, so its silently ignored, and never executed, so the other problems you have don't come up.
All of your code sits inside a block which you're passing to Product.random via Product.random do |product|. That should be product = Product.random with no do/end block.
Once you've done this, you'll start seeing more errors as you're using Product.title instead of product.title etc.

Answer 2

It looks like your product in your image_tag and link are incorrectly referencing the model and not the random one.
Try changing these:
<%= image_tag(product.image_url) %>
<h5><%= link_to product.title, product %></h5>

Answer 3

You should really generate the random product in your controller and access an instance variable in your view.
Something like:
controller's index action:
#random_product = Product.random
view:
<%= image_tag(#random_product.image_url) %>
etc.
You should never access the model directly from the view.

Answer 4

First of all, you're mixing up class methods with instance methods. Try making the view:
<div class="hide-for-small panel">
<h3>Sidebar</h3>
<h5 class="subheader">Feature Product</h5>
<%= image_tag(#product.image_url) %>
<h5><%= link_to #product.title, #product %></h5>
<p><%= button_to 'Add to Cart', line_items_path(:product_id => #product.id) %></p>
</div>
Class methods (Product.random) are defined when you don't need a specific one. So product.title if for a specific product.
Second of all, in your controller for this action, you'll need to define the #product instance variable as #product = Product.random. And then you can use that in the view.
Third of all, getting a random record could be simplified to:
Product.order("RANDOM()").first
So your model code would look like:
def self.random
Product.order("RANDOM()").first
end