Ruby On Rails SDK

Overview

Cloudinary's Ruby on Rails SDK provides simple, yet comprehensive image and video upload, transformation, optimization, and delivery capabilities that you can implement using code that integrates seamlessly with your existing Ruby on Rails application.

Quick example: Transformations

Take a look at the following transformation code and the image it delivers:

cl_image_tag("front_face.png", :secure=>true, :transformation=>[
  {:width=>150, :height=>150, :gravity=>"face", :crop=>"thumb"},
  {:radius=>20},
  {:effect=>"sepia"},
  {:overlay=>"cloudinary_icon_blue", :gravity=>"south_east", :x=>5, :y=>5, :width=>50, :opacity=>60, :effect=>"brightness:200"},
  {:angle=>10}
  ])

This relatively simple code performs all of the following on the original front_face.jpg image before delivering it:

• Crop to a 150x150 thumbnail using face-detection gravity to automatically determine the location for the crop
• Round the corners with a 20 pixel radius
• Apply a sepia effect
• Overlay the Cloudinary logo on the southeast corner of the image (with a slight offset). The logo is scaled down to a 50 pixel width, with increased brightness and partial transparency (opacity = 60%)
• Rotate the resulting image (including the overlay) by 10 degrees
• Convert and deliver the image in PNG format (the originally uploaded image was a JPG)

And here's the URL that would be included in the image tag that's automatically generated from the above code:

In a similar way, you can transform a video.

Quick example: File upload

The following Ruby code uploads the dog.mp4 video to the specified account sub-folder using the public_id, my_dog. The video will overwrite the existing my_dog video if it exists. When the video upload is complete, the specified notification URL will receive details about the uploaded media asset.

Cloudinary::Uploader.upload("dog.mp4", 
  :folder => "myfolder/mysubfolder/", :public_id => "my_dog", :overwrite => true, 
  :notification_url => "https://mysite.example.com/notify_endpoint", :resource_type => "video")

Ruby gem features

Cloudinary provides a Ruby gem (open source) that simplifies the integration with your Ruby and Ruby on Rails applications:

• Build URLs for image and video transformations
• Rails view helper tags for embedding and transforming images
• API wrappers: file upload, administration, sprite generation and more
• Server-side file upload + direct unsigned file upload from the browser using the jQuery plugin
• Migration tool
• Active Storage integration
• CarrierWave plugin
• Static image syncing for CDN delivery
• General Ruby integration for non-Rails frameworks such as Sinatra

Installation

Cloudinary's Ruby library is available as an open-source Ruby gem.

To install the Cloudinary Ruby gem, run:

gem install cloudinary

If you use Rails 3.x or later, edit your Gemfile, add the following line and run bundle.

gem 'cloudinary'

Or in Rails 5.x, edit your environment.rb and add:

config.gem 'cloudinary'

Configuration

To use the Cloudinary Ruby on Rails library, you have to configure at least your cloud_name. Your api_key and api_secret are also needed for secure API calls to Cloudinary (e.g., image and video uploads). You can find your account-specific configuration credentials in the Dashboard page of the account console.

In addition to the required configuration parameters, you can define a number of optional configuration parameters if relevant.

You can set your configuration parameters:

• Individually, by passing configuration parameters in Cloudinary method calls
• Globally by defining the CLOUDINARY_URL environment variable (required parameters only)
• Globally in a cloudinary.yml file
• Globally in a Rails initializer file

Setting the CLOUDINARY_URL environment variable

You can configure the required cloud_name, api_key, and api_secret by defining the CLOUDINARY_URL environment variable. The CLOUDINARY_URL value is available in the Dashboard page of the account console. When using Cloudinary through a PaaS add-on (e.g., Heroku or AppFog), this environment variable is automatically defined in your deployment environment. For example:

CLOUDINARY_URL=cloudinary://my_key:my_secret@my_cloud_name

Set additional parameters, for example upload_prefix and cname, to the environment variable:

CLOUDINARY_URL=cloudinary://my_key:my_secret@my_cloud_name?cname=mydomain.com&upload_prefix=myprefix.com

Configuring in the cloudinary.yml file

You create the cloudinary.yml under the config directory of your Rails project.

You can download a pre-customized cloudinary.yml configuration file in the Dashboard page of your Management Console.

Here's an example of a cloudinary.yml file:

production:
  cloud_name: "sample"
  api_key: "874837483274837"
  api_secret: "a676b67565c6767a6767d6767f676fe1"
  secure: true
  cdn_subdomain: true

Configuring in the Rails initializer file

You can place a file named cloudinary.rb in the /config/initializers folder of your Rails project. Here's some sample initializer code:

Cloudinary.config do |config|
  config.cloud_name = 'sample'
  config.api_key = '874837483274837'
  config.api_secret = 'a676b67565c6767a6767d6767f676fe1'
  config.secure = true
  config.cdn_subdomain = true
end

Ruby capitalization and data type guidelines

When using the Ruby on Rails SDK, keep these guidelines in mind:

• Parameter names: snake_case. For example: public_id
• Classes: PascalCase. For example: PictureUploader
• Methods: snake_case. For example: cl_image_upload_tag
• Pass parameter data as: Hash

Sample projects

For additional useful code samples and to learn how to integrate Cloudinary with your Rails applications, take a look at our Sample Projects.

• Basic Ruby sample: Uploading local and remote images to Cloudinary and generating various transformation URLs.
• Basic Rails sample: Uploading local and remote images in a Rails project while embedding various transformed images in a Rails web view.
• Rails Photo Album: A fully working web application. It uses CarrierWave to manage images of an album model (database). Performs image uploading both from the server side and directly from the browser using a jQuery plugin.