Question

I have a model that has a main_image per asset and in the attachment model this can only have one true value per asset. I am wondering if there is a way to pull this record without looping through every record to see if main_image is set to true or false.

Clarification:

I can find the value by using the following code:

<% @asset.attachments.each_with_index do |attachment, i| %>
    <%= image_tag(attachment.attachment.s_640_480) if !attachment.main_image.nil? && attachment.main_image%>
<%end%>

but, I am wondering how to do this without a loop…
I don’t know how to clarify any more…but something like:

 <%= image_tag(@attachment.where_main_image.s_640_480) %> 

I know that won’t work but basically that is the concept

Answer 1

<%= image_tag(@asset.attachments.find_by_main_image(true).attachment.s_640_480) %>

It’s not so nice to have this code in your view, so I’d recommend to put it in an instance method of your asset model:

class Asset < ActiveRecord::Base
  has_many :attachments

  def main_image 
    attachments.find_by_main_image(true).attachment.s_640_480
  end
end

Then in your view you can do:

<%= image_tag(@asset.main_image) %>

You probably have to add some checks that objects are not nil. Good luck.