What is the Rails way of handling edits made to a resource's ActiveStorage attachment(s)?

Question

I'm trying out ActiveStorage for the first time and wondering what the convention is for controller code used to purge some or all of a resource's attached files?

Two solutions I can see, and hate:

1. A designated controller just for managing attachments (which would omit any kind of resource specific callbacks)
2. In each resource controller add some kind of logic to the destroy methods

What is the Rails way of handling edits made to a resource's ActiveStorage attachment(s)?

Answer 1

I’d choose the first solution you considered:

A designated controller just for managing attachments (which would omit any kind of resource specific callbacks

This is roughly what we do in Basecamp. Here’s a demo:

# app/models/event.rb
class Event < ApplicationRecord
  belongs_to :user
  has_many_attached :highlights
end

# app/controllers/events/highlights_controller.rb
class Events::HighlightsController < ApplicationController
  before_action :set_event, :set_highlight

  def destroy
    @highlight.purge_later
    redirect_to @event
  end

  private
    def set_event
      @event = Current.user.events.find(params[:event_id])
    end

    def set_highlight
      @highlight = @event.highlights.find(params[:id])
    end
end

# config/routes.rb
Rails.application.routes.draw do
  resources :events do
    resources :highlights, controller: "events/highlights"
  end
end

<%# app/views/events/show.html.erb %>
<% @event.highlights.each do |highlight| %>
  <%= link_to image_tag(highlight.representation(resize: "200x200>")), highlight %><br>
  <%= link_to "Delete this highlight", event_highlight_path(@event, highlight), method: :delete %>
<% end %>