CarrierWave::Cloudflare

This gem integrates CarrierWave with Cloudflare Image Resizing

Installation

Add this line to your application's Gemfile:

gem 'carrierwave-cloudflare'

And then execute:

$ bundle install

Or install it yourself with:

$ gem install carrierwave-cloudflare

Usage

Include CarrierWave::Cloudflare in your base uploader

class BaseUploader < CarrierWave::Uploader::Base
  include CarrierWave::Cloudflare
end

Use cdn_transform to define Cloudflare's version (this means that now the file will not be stored on a server, but will be transformed on the Cloudflare side)

class AvatarUploader < BaseUploader
  version(:medium) do
    cdn_transform width: 100, height: 100, dpr: 2
  end
end

user = User.find(some_id)
user.avatar.medium # CarrierWave::Uploader
user.avatar.url # "https://s3.your-website.com/users/avatar/1.jpg"
user.avatar.medium_url   # "https://s3.your-website.com/cdn-cgi/width=100,height=100,dpr=2/users/avatar/1.jpg"
user.avatar.url(:medium) # "https://s3.your-website.com/cdn-cgi/width=100,height=100,dpr=2/users/avatar/1.jpg"
user.avatar.medium.url(dpr: 1) # "https://s3.your-website.com/cdn-cgi/width=100,height=100,dpr=1/users/avatar/1.jpg"
user.avatar.resize(width: 1200, fit: :cover).url # "https://s3.your-website.com/cdn-cgi/width=1200,height=100,dpr=2,fit=cover/users/avatar/1.jpg"

Options

Supported options:

width, height, dpr, fit, gravity, quality, format, onerror, metadata

See details in Cloudflare's documentation

You can also define default options (supports all options described above)

class BaseUploader < CarrierWave::Uploader::Base
  default_cdn_options format: :auto
end

In development env

In development you don't need to generate URLs for Cloudflare, because they will not work and therefore you need to disable the Cloudflare transform

CarrierWave::Cloudflare.configure do |config|
  config.cloudflare_transform(false)
end

cloudflare_transform: false disables links generation and puts all Cloudflare's arguments into query string (for easy debugging)

/1.jpg?cdn-cgi=width-11.height-300.fit-pad

Rails views helpers

cdn_transformed(url, **options)

Returns an image URL with CDN transformations applied. Can process already transformed URLs, in that case the options will be merged together.

cdn_transformed('/img.jpg', width: 400)
# => '/cdn-cgi/image/width=400/img.jpg'

cdn_transformed('/cdn-cgi/image/width=100,fit=pad/img.jpg', width: 333)
# => '/cdn-cgi/image/width=333,fit=pad/img.jpg'

hidpi_image_tag(url, dprs: nil, **options)

Returns an image tag with scaled variations (via srcset) attribute for devices with different DPR values.

The transformation of the original image should be specified via options.

hidpi_image_tag('/bird.jpg', width: 400, drps: [1, 2])
# => <img srcset="/cdn-cgi/image/width=400,dpr=1/img.jpg 1x, /cdn-cgi/image/width=400,dpr=2/img.jpg 2x" src="/cdn-cgi/image/width=400/img.jpg" />

responsive_image_tag(url, width:, sizes: nil, dprs: [1, 2], **options)

Returns a reponsive image tag with variations.

responsive_image_tag('/bird.jpg', width: 1200, sizes: { phone: 600, tablet: 800 })

# => <img srcset="/cdn-cgi/image/width=1200,dpr=0.5/bird.jpg 600w,
#                  /cdn-cgi/image/width=1200,dpr=1.0/bird.jpg 1200w,
#                  /cdn-cgi/image/width=1200,dpr=0.67/bird.jpg 800w,
#                  /cdn-cgi/image/width=1200,dpr=1.33/bird.jpg 1600w,
#                  /cdn-cgi/image/width=1200,dpr=2.0/bird.jpg 2400w"
#                  sizes="(max-width: 767px) 600px, (max-width: 1023px) 800px, 1200px"
#                  src="/cdn-cgi/image/width=1200/bird.jpg" />

Development

After checking out the repo, run bin/setup to install dependencies. Then run rake spec to run the tests. You can also run bin/console for an interactive prompt that will allow you to experiment.

To install this gem onto your local machine, run bundle exec rake install. To release a new version, update the version number in version.rb, and then run bundle exec rake release, which will create a git tag for the version, push git commits and tags, and push the .gem file to rubygems.org.

License

This project is licensed and distributed under the terms of the MIT license.