SimpleActiveStorage

first of all,I need to apologize for my pool english.

when you using active storage there are some inconvenient things, such as you get the url of attachment:

user.avatar.variant(resize: "100x100")

you need repeat resize: "100x100" every time.

I need a short cut to replace resize: "100x100", like this:

user.avatar.variant(:thumb)
user.avatar.path
user.avatar.url

SimpleActiveStorage is do such thing.

Usage

generate config file: rails g simple_active_storage it will generate a file located at: config/initializers/simple_active_storage.rb content look like this:

SimpleActiveStorage.default_url_options = {host: "www.example.com"}
SimpleActiveStorage.transformation :thumb do
  {resize: "100x100"}
end
SimpleActiveStorage.transformation :tiny do
  {resize: "20x20"}
end
SimpleActiveStorage.transformation :medium do
  {resize: "400x400"}
end

app/models/user.rb

class User < ApplicationRecord
  has_one_attached  :avatar
  has_many_attached :photos
end

user = User.first
user.avatar.attach io: File.new(Rails.root.join("test","fixtures","files","test.png")),filename: "test.png"
user.photos.attach io: File.new(Rails.root.join("test","fixtures","files","test.png")),filename: "test.png"
user.avatar.path # => "/rails/active_storage/blobs/eyJfcmFpbHMiOnsibWVzc2FnZSI6IkJBaHBCZz09IiwiZXhwIjpudWxsLCJwdXIiOiJibG9iX2lkIn19--08f03241905408289698b118698ca7642c3e691e/test.png"
user.avatar.url  # => "http://www.example.com/rails/active_storage/blobs/eyJfcmFpbHMiOnsibWVzc2FnZSI6IkJBaHBCZz09IiwiZXhwIjpudWxsLCJwdXIiOiJibG9iX2lkIn19--08f03241905408289698b118698ca7642c3e691e/test.png"
user.avatar.variant(:thumb).path # => "http://www.example.com/rails/active_storage/representations/eyJfcmFpbHMiOnsibWVzc2FnZSI6IkJBaHBCZz09IiwiZXhwIjpudWxsLCJwdXIiOiJibG9iX2lkIn19--08f03241905408289698b118698ca7642c3e691e/eyJfcmFpbHMiOnsibWVzc2FnZSI6IkJBaDdCam9VWTI5dFltbHVaVjl2Y0hScGIyNXpld1k2QzNKbGMybDZaVWtpRERFd01IZ3hNREFHT2daRlZBPT0iLCJleHAiOm51bGwsInB1ciI6InZhcmlhdGlvbiJ9fQ==--20ae94033d7a10dcb862bd24c1dcbb3740e61e7c/test.png"
user.avatar.variant(:thumb).url  # => "http://www.example.com/rails/active_storage/representations/eyJfcmFpbHMiOnsibWVzc2FnZSI6IkJBaHBCZz09IiwiZXhwIjpudWxsLCJwdXIiOiJibG9iX2lkIn19--08f03241905408289698b118698ca7642c3e691e/eyJfcmFpbHMiOnsibWVzc2FnZSI6IkJBaDdCam9VWTI5dFltbHVaVjl2Y0hScGIyNXpld1k2QzNKbGMybDZaVWtpRERFd01IZ3hNREFHT2daRlZBPT0iLCJleHAiOm51bGwsInB1ciI6InZhcmlhdGlvbiJ9fQ==--20ae94033d7a10dcb862bd24c1dcbb3740e61e7c/test.png"
photo = user.photos[0]
photo.variant(:thumb).url # =>"http://www.example.com/rails/active_storage/representations/eyJfcmFpbHMiOnsibWVzc2FnZSI6IkJBaHBCdz09IiwiZXhwIjpudWxsLCJwdXIiOiJibG9iX2lkIn19--e81a87b1d919f371e6b665e2c01301cff6d16a26/eyJfcmFpbHMiOnsibWVzc2FnZSI6IkJBaDdCam9VWTI5dFltbHVaVjl2Y0hScGIyNXpld1k2QzNKbGMybDZaVWtpRERFd01IZ3hNREFHT2daRlZBPT0iLCJleHAiOm51bGwsInB1ciI6InZhcmlhdGlvbiJ9fQ==--20ae94033d7a10dcb862bd24c1dcbb3740e61e7c/test.png"
photo.url                 # => "http://www.example.com/rails/active_storage/blobs/eyJfcmFpbHMiOnsibWVzc2FnZSI6IkJBaHBCdz09IiwiZXhwIjpudWxsLCJwdXIiOiJibG9iX2lkIn19--e81a87b1d919f371e6b665e2c01301cff6d16a26/test.png"
photo.blob.url            # => "http://www.example.com/rails/active_storage/blobs/eyJfcmFpbHMiOnsibWVzc2FnZSI6IkJBaHBCdz09IiwiZXhwIjpudWxsLCJwdXIiOiJibG9iX2lkIn19--e81a87b1d919f371e6b665e2c01301cff6d16a26/test.png"

direct upload

when use activestorage direct upload activestorage.js will make an ajax post to /rails/active_storage/direct_uploads and return json data it looks like below:

{
    "id": 4,
    "key": "veeUd2b2toSbym6DmZ2pLkoZ",
    "filename": "avatar.jpg",
    "content_type": "image/jpeg",
    "metadata": {},
    "byte_size": 145516,
    "checksum": "/uNyp1jXJPXLBD6X0XZn7g==",
    "created_at": "2018-05-29T16:50:51.801Z",
    "signed_id": "eyJfcmFpbHMiOnsibWVzc2FnZSI6IkJBaHBDUT09IiwiZXhwIjpudWxsLCJwdXIiOiJibG9iX2lkIn19--578572a7c2d5925ac32622a7d7b832f68c536f51",
    "direct_upload": {
        "url": "http://localhost:3001/rails/active_storage/disk/eyJfcmFpbHMiOnsibWVzc2FnZSI6IkJBaDdDVG9JYTJWNVNTSWRkbVZsVldReVlqSjBiMU5pZVcwMlJHMWFNbkJNYTI5YUJqb0dSVlE2RVdOdmJuUmxiblJmZEhsd1pVa2lEMmx0WVdkbEwycHdaV2NHT3daVU9oTmpiMjUwWlc1MFgyeGxibWQwYUdrRGJEZ0NPZzFqYUdWamEzTjFiVWtpSFM5MVRubHdNV3BZU2xCWVRFSkVObGd3V0ZwdU4yYzlQUVk3QmxRPSIsImV4cCI6IjIwMTgtMDUtMjlUMTY6NTU6NTIuMTgxWiIsInB1ciI6ImJsb2JfdG9rZW4ifX0=--b2deb5a21ef8b7a2a08cf354052a65e640be6450",
        "headers": {
            "Content-Type": "image/jpeg"
        }
    },
    "transformations": {
        "thumb": "http://www.example.com/rails/active_storage/representations/eyJfcmFpbHMiOnsibWVzc2FnZSI6IkJBaHBDUT09IiwiZXhwIjpudWxsLCJwdXIiOiJibG9iX2lkIn19--578572a7c2d5925ac32622a7d7b832f68c536f51/eyJfcmFpbHMiOnsibWVzc2FnZSI6IkJBaDdCam9VWTI5dFltbHVaVjl2Y0hScGIyNXpld1k2QzNKbGMybDZaVWtpRERFd01IZ3hNREFHT2daRlZBPT0iLCJleHAiOm51bGwsInB1ciI6InZhcmlhdGlvbiJ9fQ==--20ae94033d7a10dcb862bd24c1dcbb3740e61e7c/avatar.jpg",
        "tiny": "http://www.example.com/rails/active_storage/representations/eyJfcmFpbHMiOnsibWVzc2FnZSI6IkJBaHBDUT09IiwiZXhwIjpudWxsLCJwdXIiOiJibG9iX2lkIn19--578572a7c2d5925ac32622a7d7b832f68c536f51/eyJfcmFpbHMiOnsibWVzc2FnZSI6IkJBaDdCam9VWTI5dFltbHVaVjl2Y0hScGIyNXpld1k2QzNKbGMybDZaVWtpQ2pJd2VESXdCam9HUlZRPSIsImV4cCI6bnVsbCwicHVyIjoidmFyaWF0aW9uIn19--c8fb6fe35e8d91c55a9323e9858130607ecdb1bf/avatar.jpg",
        "medium": "http://www.example.com/rails/active_storage/representations/eyJfcmFpbHMiOnsibWVzc2FnZSI6IkJBaHBDUT09IiwiZXhwIjpudWxsLCJwdXIiOiJibG9iX2lkIn19--578572a7c2d5925ac32622a7d7b832f68c536f51/eyJfcmFpbHMiOnsibWVzc2FnZSI6IkJBaDdCam9VWTI5dFltbHVaVjl2Y0hScGIyNXpld1k2QzNKbGMybDZaVWtpRERRd01IZzBNREFHT2daRlZBPT0iLCJleHAiOm51bGwsInB1ciI6InZhcmlhdGlvbiJ9fQ==--b87eb27c4abc3f9bd937642f2e5809bfd553edf8/avatar.jpg"
    }
}

originally there is no transformations field in json data. the transformations field data is provide by SimpleActiveStorage.

short cut url

the representation url is very long because rails encrypted transformation information to a very long string

http://www.example.com/rails/active_storage/representations/eyJfcmFpbHMiOnsibWVzc2FnZSI6IkJBaHBDUT09IiwiZXhwIjpudWxsLCJwdXIiOiJibG9iX2lkIn19--578572a7c2d5925ac32622a7d7b832f68c536f51/eyJfcmFpbHMiOnsibWVzc2FnZSI6IkJBaDdCam9VWTI5dFltbHVaVjl2Y0hScGIyNXpld1k2QzNKbGMybDZaVWtpRERRd01IZzBNREFHT2daRlZBPT0iLCJleHAiOm51bGwsInB1ciI6InZhcmlhdGlvbiJ9fQ==--b87eb27c4abc3f9bd937642f2e5809bfd553edf8/avatar.jpg

eyJfcmFpbHMiOnsibWVzc2FnZSI6IkJBaDdCam9VWTI5dFltbHVaVjl2Y0hScGIyNXpld1k2QzNKbGMybDZaVWtpRERRd01IZzBNREFHT2daRlZBPT0iLCJleHAiOm51bGwsInB1ciI6InZhcmlhdGlvbiJ9fQ==--b87eb27c4abc3f9bd937642f2e5809bfd553edf8

this is part of the representation url included transformation information , can be decrypted by rails if you turned on by set

SimpleActiveStorage.config.enable_shortcut_url = true

you will get this short url:

http://www.example.com/rails/active_storage/representations/eyJfcmFpbHMiOnsibWVzc2FnZSI6IkJBaHBDUT09IiwiZXhwIjpudWxsLCJwdXIiOiJibG9iX2lkIn19--578572a7c2d5925ac32622a7d7b832f68c536f51/thumb/avatar.jpg

the difference between two urls is that transofrmation(variantation_key) part.

auto remove duplicate blobs

user = User.first avatar = user.avatar user.photos.attach avatar.blob user.photos.attach avatar.blob # raise error without simple active storage user.photos.attachments.size # 1

Installation

Add this line to your application's Gemfile:

gem 'simple_active_storage'

And then execute:

$ bundle

Or install it yourself as:

$ gem install simple_active_storage

Contributing

visit http://www.github.com/aotianlong/simple_active_storage pull requests are welcome.

License

The gem is available as open source under the terms of the MIT License.