Filestack (formerly Filepicker) is a service that allows users to store files in a cloud. It has a free plan with some monthly limits: 250 uploads, 500 transformations and 3GB bandwidth. Those numbers get higher if you select one of paid plans. You can also use external storage (S3, Dropbox…), though you have to select any paid plan to enable this feature. Here’s how to use Filestack in a Rails app.

I assume you have:

• Account created on filestack.com, API key obtained (it’s generated automatically after registration)
• Rails app with User model created (rails-devise is a good starting point)

What you will use:

• Filepicker-rails - gem to make uploads easier to implement (to quickly see how it works you can use this repository or just follow the steps below)

Pros:

• Simple to implement
• Files can be uploaded directly from many different sources such as Google Drive, Facebook, Instagram, etc.
• Images can be cropped before upload

Cons:

The only gem I found isn’t updated very often, last commit was in October 2015

Step 1

Add filepicker-rails gem to your gemfile:

gem 'filepicker-rails'

Step 2

Include Filestack js file in your layout:

<%= filepicker_js_include_tag %>

Step 3

Add your Filestack API key to config/application.rb:

config.filepicker_rails.api_key = ENV['FILESTACK_API_KEY']

Step 4

Add helpers to your ApplicationController:

helper FilepickerRails::Engine.helpers

Step 5

Create a migration to add a string column which will store uploaded files urls, e.g. users’ avatars:

class AddAvatarUrlToUsers < ActiveRecord::Migration
  def change
    add_column :users, :avatar_url, :string
  end
end

Step 6

Implement the form used to upload a file:

<%= form_for @user do |f| %>
  <div>
    <%= f.label :avatar_url, 'Upload Your Avatar:' %>
    <%= f.filepicker_field :avatar_url, dragdrop: true %>
  </div>
  <%= f.submit %>
<% end %>

You can read about different filepicker_field options here.

Modal that will allow you to upload your file looks like that:

If you use devise, remember to properly configure permitted parameters in your ApplicationController (this works for devise 3, there’s a different syntax in devise 4):

before_action :configure_permitted_parameters, if: :devise_controller?

protected

def configure_permitted_parameters
  devise_parameter_sanitizer.for(:sign_up) << :avatar_url
end

Step 7

In order to display an avatar after submitting the form, you can use this helper:

<%= filepicker_image_tag @user.avatar_url %>

To know more about the FileStack integration, head over to their documentation page.