Ruby On Rails integration

Overview

Cloudinary is a cloud-based service that provides an end-to-end image management solution including uploads, storage, manipulations, optimizations and delivery.

With Cloudinary you can easily upload images to the cloud, automatically perform smart image manipulations without installing any complex software. All your images are then seamlessly delivered through a fast CDN, optimized and using industry best practices. Cloudinary offers comprehensive APIs and administration capabilities and is easy to integrate with new and existing web and mobile applications.

Quick example

Take a look at the following Cloudinary URL that generates the image below:

http://res.cloudinary.com/demo/image/upload/w_150,h_150,c_thumb,g_face,r_20,e_sepia/l_cloudinary_icon,g_south_east,x_5,y_5,w_50,o_60,e_brightness:200/a_10/front_face.png

174x174 PNG

Simply accessing the above URL told Cloudinary to transform an uploaded image, create a 150x150px thumbnail using face detection based cropping, round the image's corners, add a sepia effect, convert it to a transparent PNG format, add a watermark layer, rotate the image by 10 degrees and ultimately delivered the resulting image through a fast CDN using smart caching techniques.

Ruby GEM Features

Cloudinary provides a Ruby GEM (open source) for further simplifying the integration:

Build URLs for image transformation & manipulation.
Rails view helper tags for embedding and transforming images.
API wrappers: image upload, administration, sprite generation and more.
Direct image uploading from the browser using a jQuery plugin.
Active Record integration.
CarrierWave plugin.
Static images syncing for CDN delivery.
Migration tool.
General Ruby integration for non-Rails frameworks such as Sinatra.

The GEM was tested with Ruby 1.8.7, 1.9.2, 1.9.3 and Rails 2.3.x, 3.0.x, 3.1.x, 3.2.x, 4.0.x.

Rails - Getting started guide

1Installation

Cloudinary's Ruby integration 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 higher, edit your Gemfile, add the following line and run bundle.

gem 'cloudinary'

Or in Rails 2.x, edit your environment.rb and add:

config.gem 'cloudinary'

2Configuration

Your cloud_name account parameter is required to build image URLs. api_key and api_secret are further needed to perform secure API calls to Cloudinary (e.g., image uploads). See API, URLs and access identifiers for more details.

Setting the configuration parameters can be done either programmatically in each call to a Cloudinary method or globally using a cloudinary.yml configuration file, located under the config directory of your Rails project.

You can download your customized cloudinary.yml configuration file through our Management Console.

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

production:
  cloud_name: "sample"
  api_key: "874837483274837"
  api_secret: "a676b67565c6767a6767d6767f676fe1"

See Configuration Options for more details and additional configuration methods.

3Upload images

You can upload images and any other files from your Ruby code or Ruby on Rails server. Uploading is done over HTTPS using a secure protocol based on the api_key and api_secret parameters you provide.

The following command uploads a local file to Cloudinary:

Cloudinary::Uploader.upload('/home/my_image.jpg')

Alternatively, you can a specify a local path, a public HTTP URL, an S3 URL, an IO stream or an actual image file's data. For example:

Cloudinary::Uploader.upload('http://www.example.com/image.jpg')

Each image uploaded to Cloudinary is assigned a unique Public ID and is available for immediate delivery and transformation. The upload method returns a Hash with content similar to that shown in the following example:

{
 "url" => 'http://res.cloudinary.com/demo/image/upload/v1371281596/sample.jpg',
 "secure_url" => 
          'https://res.cloudinary.com/demo/image/upload/v1371281596/sample.jpg',
 "public_id" => 'sample',
 "version" => '1312461204',
 "format" => 'jpg',
 "width" => 864,
 "height" => 564,
 "bytes" => 120253       
}

As you can see in the following example, with a single call you can define your own Public ID, apply an incoming image transformation before storing the image in the cloud, generate derived images eagerly and assign tags to uploaded images:

Cloudinary::Uploader.upload(params[:image],
                            :public_id => "sample_id",
                            :crop => :limit, :width => 2000, :height => 2000,
                            :eager => [
                              { :width => 200, :height => 200, 
                                :crop => :thumb, :gravity => :face,
                                :radius => 20, :effect => :sepia },
                              { :width => 100, :height => 150, 
                                :crop => :fit, :format => 'png' }
                            ],                                     
                            :tags => ['special', 'for_homepage'])

Many more upload options as well as direct image uploading from the browser are detailed here: Rails image upload.

You can also use Cloudinary's CarrierWave plugin to manage your attachments uploading, transformation and embedding within your views.

Cloudinary supports uploading videos as well. See Upload videos documentation page for more details.

4Display and manipulate images

Adding images to your Rails view is quite straightforward. Just use the cl_image_tag helper method instead of the standard image_tag method. This method generates the full image resource URL based on the given parameters and internally uses image_tag to add the image to your HTML code:

For example, displaying the uploaded image with the sample public ID, while providing an alternate text:

cl_image_tag("sample.jpg", :alt => "Sample Image")

864x576 JPG (Scaled down)

Now, let's say that you wish to display a small thumbnail of this uploaded image. Simply add the transformation instructions to your call. For example, displaying the 'sample' image transformed to fill a 100x150 rectangle:

cl_image_tag("sample.jpg", :width => 100, :height => 150, :crop => :fill)

100x150 JPG

This is equivalent to:

image_tag(
  "http://res.cloudinary.com/demo/image/upload/w_100,h_150,c_fill/sample.jpg", 
  :width => 100, :height => 150)

Using simple parameters you can perform powerful image manipulations. The Ruby library builds Cloudinary URLs that you can embed in your web and mobile views for dynamically transforming your uploaded images in the cloud and delivering the results through a fast CDN with advanced caching.

You can easily convert image formats, resize your images, perform face detection based cropping, apply effects and filters, append textual layers or watermarks and more.

The following command, for example, embeds a JPG thumbnail of a profile photo fetched from Facebook in real-time, crops it to a circle, applies a sepia effect and delivers it optimized through a CDN:

facebook_profile_image_tag("billclinton.jpg", :width => 90, :height => 98, 
                           :crop => :fill, :gravity => :face,
                           :radius => :max, :effect => :sepia)

90x98 JPG

For a full list of supported transformations and their usage, refer to Image transformations.

For more details about Cloudinary's image transformation and manipulation in Ruby on Rails, see Rails image manipulation.

Videos can be delivered and manipulated as well. See Video manipulation and delivery documentation page for more details.

5Sample projects

To find additional useful code samples and 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.

https://github.com/cloudinary/cloudinary_gem/tree/master/samples

6What's next

Sign up for a free account if you haven't done so already. Follow the steps above and try Cloudinary out. Finished all steps? That's just an example of what Cloudinary can offer. Here's some additional reading material to help you get the best out of Cloudinary:

Learn more about Rails image upload.

Explore powerful Rails image manipulation features and see our Image transformations docs.

Make sure to read about Rails & CarrierWave integration and Attachinary.

Browse additional Ruby on Rails integration topics: configuration, migration, Admin API, etc.

Stay tuned for updates, tips and tutorials: Blog, Twitter, Facebook.

CarrierWave integration

Cloudinary's Ruby GEM includes a plugin for CarrierWave. You can use CarrierWave to manage your model attachments: all files and images are automatically uploaded to Cloudinary, image manipulations are performed dynamically in the cloud and all resulting images are delivered through a CDN.

See our detailed documentation about Cloudinary's plugin for CarrierWave for more details.