onebox

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Onebox is a library for turning media URLs into simple HTML previews of the resource.

Onebox currently has support for page, image, and video URLs for many popular sites.

It's great if you want users to input URLs and have your application convert them into rich previews for display. For example, a link to a YouTube video would be automatically converted into a video player.

It was originally created for Discourse but has since been extracted into this convenient gem for all to use!

Usage

Using onebox is fairly simple! First, make sure the library is required:

require "onebox"

Then pass a link to the library's interface:

require "onebox"

url = "http://www.amazon.com/gp/product/B005T3GRNW/ref=s9_simh_gw_p147_d0_i2"
preview = Onebox.preview(url)

This will contain a simple Onebox::Preview object that handles all the transformation. From here you either call Onebox::Preview#to_s or just pass the object to a string:

require "onebox"

url = "http://www.amazon.com/gp/product/B005T3GRNW/ref=s9_simh_gw_p147_d0_i2"
preview = Onebox.preview(url)
"#{preview}" == preview.to_s #=> true

Onebox has its own caching system but you can also provide (or turn off) your own system:

require "onebox"

url = "http://www.amazon.com/gp/product/B005T3GRNW/ref=s9_simh_gw_p147_d0_i2"
preview = Onebox.preview(url, cache: Rails.cache)
"#{preview}" == preview.to_s #=> true

In addition you can set your own options with this handy interface:

require "onebox"

Onebox.options = {
  cache: Rails.cache
}

url = "http://www.amazon.com/gp/product/B005T3GRNW/ref=s9_simh_gw_p147_d0_i2"
preview = Onebox.preview(url)
"#{preview}" == preview.to_s #=> true

Adding Support for a new URL

  1. Check if the site supports oEmbed or Open Graph. If it does, you can probably get away with just whitelisting the URL in Onebox::Engine::WhitelistedGenericOnebox. If the site does not support open standards, you can create a new engine.

  2. Create new onebox engine

    # in lib/onebox/engine/name_onebox.rb
    
    module Onebox
      module Engine
        class NameOnebox
          include LayoutSupport
          include HTML
    
          private
    
          def data
            {
              url: @url,
              name: raw.css("h1").inner_text,
              image: raw.css("#main-image").first["src"],
              description: raw.css("#postBodyPS").inner_text
            }
          end
        end
      end
    end
    
  3. Create new onebox spec using FakeWeb

    # in spec/lib/onebox/engine/name_spec.rb
    require "spec_helper"
    
    describe Onebox::Engine::NameOnebox do
      let(:link) { "http://example.com" }
      let(:html) { described_class.new(link).to_html }
    
      before do
        fake(link, response("name.response"))
      end
    
      it "has the video's title" do
        expect(html).to include("title")
      end
    
      it "has the video's still shot" do
        expect(html).to include("photo.jpg")
      end
    
      it "has the video's description" do
        expect(html).to include("description")
      end
    
      it "has the URL to the resource" do
        expect(html).to include(link)
      end
    end
    
  4. Create new mustache template

    # in templates/name.mustache
    <div class="onebox">
      <a href="{{url}}">
        <h1>{{name}}</h1>
        <h2 class="host">example.com</h2>
        <img src="{{image}}" />
        <p>{{description}}</p>
      </a>
    </div>
    
  5. Create new fixture from HTML response for your FakeWeb request(s)

    curl --output spec/fixtures/oneboxname.response -L -X -GET http://example.com
    
  6. Require in Engine module

    # in lib/onebox/engine.rb
    require_relative "engine/name_onebox"
    

Installing

Add this line to your application's Gemfile:

gem "onebox". "~> 1.2"

And then execute:

$ bundle

Or install it yourself as:

$ gem install onebox

Contributing

  1. Fork it
  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