Access attributes in controller while looping in view

Question

I have a loop in my view:

<% @deals.each do |d| %>


<% end %>

Deal and ListItem share the :code attribute.

If I wanted to count all the list_items that shared :code with a certain deal, how can I do this in the controller while iterating through the loop?

I understand it's bad form to access Models in the view correct? So that would rule out doing something like this in the loop right?:

<%= "#{ListItem.where(:code => d.code).count}" %>

Can I use a variable or some custom method to achieve this? Please let me know if I can clarify. Thank you!

Answer 1

You want to do all the calculation on the server in your controller action before rendering the view.

So in addition to gathering the @deals, you will also set an instance variable for the count.

def index
  @deals = Deals.all # or whatever your finder is

  @common_listitem_count = ListItem.where(code: @deals.pluck(:code)).count
end

Then just call the count instance variable in the view:

<%= @common_listitem_count %>