Reprocess Paperclip attachments in one line

When Paperclip attachments should only be downloadable for selected users, there are three ways to go.
The same applies to files in Carrierwave.
...

When a paperclip attachment gains a new style and you have many attachments, reprocessing can take ages. This is because all styles are being recomputed.

To create only missing images, patch Paperclip like this in your script that does the reproc...

to_file has been removed in Paperclip 3.0.1.

Instead of using File to access Paperclip storage objects (like this: File.read(file.to_file.path)) you can use

Paperclip.io_adapters.fo...

tl;dr: Always have your attachment path start with :rails_root/storage/#{Rails.env}#{ENV['RAILS_TEST_NUMBER']}/.

The directory where you save your Paperclip attachments should not look like this:

storage/photos/1/...
stora...

Sometimes you add Paperclip image styles, sometimes you remove some. In order to only keep the files you actually need, you should remove stale Paperclip styles from your server.

This script has been used in production successful...

Just assign the existing attachment to another record:

new_photo = Photo.new
new_photo.image = old_photo.image

Paperclip will duplicate the file when saving.

To use this in forms, pimp your attachment container like this:

class Pho...

Don't simply test for the presence of the magic Paperclip attribute, it will return a paperclip Attachment object and thus always be true:

- if user.photo.present? # always true
  = image_tag(user.photo.url)

Use #exists? instead:

...

Sometimes you just want to have a small web server that serves files to test something.

Serve the current directory

On Ruby 1.9.2+ you can do the following ("." for current directory).

ruby -run -ehttpd . -p8000

Python 2.x offers a s...

RSpec supports a one-liner syntax for setting an expectation on the subject:

describe Array do
  describe "when first created" do
    it { should be_empty }
  end
end

The example description "it should be empty" will be defined automat...

Given there is a user with an attachable avatar:

class User < ApplicationRecord
  has_one_attached :avatar
end

You can copy the avatar from one user to another user with the code below:

user_1 = User.first
user_2 = User.crea...