Removing Paperclip attachments

Paperclip’s GitHub page includes the necessary steps to delete an attachment - the model’s attribute that refers to the attachment simply gets set to nil. Here is the full implementation of deleting a user’s profile picture in a Rails app. Start with tests (right?!):

spec/features/editing_users_spec.rb:

require 'spec_helper'
feature 'Editing Users' do
  let(:user) { FactoryGirl.create(:user) }
  let(:admin) { FactoryGirl.create(:admin) }
  scenario 'removing user profile photo' do
    sign_in_as admin # of course
    visit edit_user_path(user)
    click_link 'Remove profile photo'
    expect(page).to have_content 'User profile photo has been removed.'
    expect(page).not_to have_css("img[src*='user.png']") # file name of the user photo defined in the factory
    expect(page).to have_css("img[src*='paperclip_default.png']") # specified in the User model
  end
end

(This post covers creation of an attachment in a FactoryGirl factory.)

Red. The test first fails when it tries to find a “Remove profile photo” link. In my implementation, photo removal takes place in the Edit view, so that’s where the link goes (or, to be more precise, into the ‘form’ partial):

app/views/users/_form.html.erb:

<%= form_for @user do |f| %>
  <%= f.label :photo, 'Profile photo' %>
  <%= f.file_field :photo %>
  <% if @user.persisted? %>
    <%= link_to 'Remove profile photo', remove_user_photo_path %>
  <% end %>
.
.
<% end %>

(If the user has not been persisted to the database yet, as is the case when the partial is used by the New view to create a new user, the link_to cannot be generated as there is no user id yet - see routes.rb below. This is why it is wrapped in the if..persisted? clause.)

Red. In this iteration, the test fails because remove_user_photo_path is undefined. That’s next:

config/routes.rb:

Rails.application.routes.draw do
  .
  .
  get 'user/:id/remove_photo', to: 'users#remove_photo', as: 'remove_user_photo'
end

As can be seen from the route, the link_to method used in the view will generate a url such as /user/1/remove_photo, which is why having a user id (from a persisted user) is necessary.

Red. The test now fails because the remove_photo action does not exist in the Users controller. We are finally ready to make use of Paperclip’s instructions on deleting attachments:

app/controllers/users_controller.rb:

class UsersController < ApplicationController
  .
  .
  def remove_photo
    @user = User.find(params[:id])
    @user.photo = nil
    @user.save
    redirect_to @user, flash: { success: 'User profile photo has been removed.' }
  end
end

The action pulls the relevant user record out of the database, sets its attachment-referring photo attribute to nil, and saves the user to the database. It then redirects the browser to the user’s profile page, where the profile image now displays Paperclip’s default graphic and not the photo defined in the factory.

Green :)