Rails webpacker in model

Bit of a strange scenario but let me explain. I have a view that needs to output a number of cars. The car photos are stored on Amazon S3. Some cars have photos whereas others do not. The ones that don't, need their image to display a locally stored placeholder graphic. The Car model has a boolean field to denote whether there is a photo for the car or not.

The part of the car partial is as follows:

<div class="car__photo-inner">
    <img src="<%= car.photo_or_placeholder_url({size: :thumb, aspect: :square}) %>" />
</div>

The method in my Car model is as such:

def photo_or_placeholder_url(options = {})
  if photo
    photo_url(options)
  else
    asset_pack_path File.join(["media", "images", "placeholder.jpg"])
  end
end

photo_url just uses the options to grab the correct URL from Amazon S3 and works perfectly.

Where I am struggling is with getting the placeholder image to display. The placeholder is stored in /app/javascript/images.

Any suggestions?

Many thanks, Neil

Solution

Any suggestions?

Yes. Don't do it in the model. Models in Rails are already insanely overtaxed with responsibilities. And this is actually purely a view concern. Models really should only be concerned with the business logic and not the presentation if possible.

So where then?

A helper method or a decorator:

module CarsHelper
  def car_photo(car, **options)
    url = if car.photo 
      car.photo_url(options)
    else
      "placeholder.jpg"
    end
    image_tag(url)
  end
end

<div class="car__photo-inner">
  <%= car_photo(car) %>
</div>

If the placeholder image is a developer concern just place it in app/assets/images and use the conventions instead of fighting them.