s3ff

S3FF

Using s3_file_field with paperclip.

Installation

Add this line to your application's Gemfile:

gem 's3ff'

And then execute:

$ bundle

Or install it yourself as:

$ gem install s3ff

Usage

1. Configure s3_file_field

add a config like sample/config_s3_file_field.rb into your Rails config/initializers/ directory

2. Add javascript

in your application.js

//= require s3ff

3. Change file_field input to use s3_file_field

= form_for :user do |f|
  = f.s3_file_field :avatar

or if you're using simple_form

= simple_form_for :user do |f|
  = f.input :avatar do
    = f.s3_file_field :avatar, :class => "form-control"

4. Add footer

= include_s3ff_templates

NOTE: Feel free to modify & render the templates manually, but keep the s3ff_ prefixed CSS classes for our javascript to work properly.

What will happen

To illustate, if you have a file field like this

<input type="file" name="user[avatar]">

When s3ff kicks in, it would upgrade the field to a s3_file_field. When your user chooses a file, it will be uploaded, with a progress indicator, directly into your S3 bucket (see s3_file_field gem for configuration). Your form will be disabled during the upload and re-enabled once upload completes. After this process, a new hidden form field will be attached to your form:

<input type="file" name="user[avatar_direct_url]" value="https://....">

Code changes to your app

s3ff designed to minimize moving parts and code changes to your Rails app - all it does is give you new hidden form fields in return for every direct s3 file upload that happened in your user's browser.

How you deal with these form fields are entirely up to you. Here's a simple way:

1. Edit strong parameters

If your controller was specifying

params.require(:user).permit(:avatar)

It would need to be changed to accept the new form fields

params.require(:user).permit(:avatar, :avatar_direct_url)

2. Upgrade model to also accept direct url

If your model was originally

class User < ActiveRecord::Base
  has_attached_file :avatar
  validates_attachment_content_type :avatar, content_type: /\Aimage\/.*\Z/
end

Download the file from S3 when given avatar_direct_url. This leaves all your existing Paperclip code and logic unchanged.

class User < ActiveRecord::Base
  has_attached_file :avatar
  validates_attachment_content_type :avatar, content_type: /\Aimage\/.*\Z/

  # s3ff changes

  def avatar_direct_url=(value)
    open(value, ssl_verify_mode: OpenSSL::SSL::VERIFY_NONE) do |file|
      self.attributes = {
        avatar: file,
        avatar_file_name: File.basename(value),
      }
    end
  end
end

CAVEAT

It is not ideal to handle your attachment processing synchronously inside the web request. If you have Sidekiq or DelayedJob installed, you should use the download_from_direct_url_with_delay helper method instead

class User < ActiveRecord::Base
  has_attached_file :avatar
  validates_attachment_content_type :avatar, content_type: /\Aimage\/.*\Z/

  # s3ff changes
  # for delayed_job, you MUST add a `avatar_direct_url` database column of string type
  # for sidekiq, a virtual attribute `avatar_direct_url` will be added
  download_from_direct_url_with_delay :avatar
end

Contributing

1. Fork it ( http://github.com/jollygoodcode/s3ff/fork )
2. Create your feature branch (git checkout -b my-new-feature)
3. Commit your changes (git commit -am 'Add some feature')
4. Push to the branch (git push origin my-new-feature)
5. Create new Pull Request

License

This repository is MIT-licensed, see LICENSE.