acts_as_graph_object

ActiveRecord extension that maps models to Facebook Open Graph objects.

Installation

gem install acts_as_graph_object

Then just add the dependancy to your Gemfile.

Usage

Configuration

# app/config/initializers/acts_as_graph_object.rb
ActsAsGraphObject.configure do |config|
  config.namespace = 'my-app'
  config.app_id = 12345
  config.admins = [1245, 6789]
end

Default URL Method

In order to use the built in @model.url method you need to set the following config option:

# app/config/environments/production.rb
routes.default_url_options[:host] = 'my-app.com'

Add acts_as_graph_object...

# app/models/movie.rb
class Movie < ActiveRecord::Base
  acts_as_graph_object :custom => [:director, :writer, :cast]

  def cast
    ...
  end
end

Outputting meta tags

Use the graph_object_tags_for(@movie) helper to output the resulting <meta> tags. You can use this in combination with content_for to push the results into your <head>:

# app/views/layouts/application.html.erb    
<head>
    <%= yield :meta_tags %>
</head>

# app/views/movies/show.html.erb
<% content_for :meta_tags, graph_object_tags_for(@movie) %>

Overriding from view

If you want to override a value from the view (for example to use a url_for helper):

# app/views/movies/show.html.erb
<% content_for :meta_tags, graph_object_tags_for(@movie, :url => movie_url(@movie)) %>

Alternative attribute names (v0.0.7)

You can now use non-default names for the standard Open Graph properties and the Gem will attempt to pick these up. Here are the properties and their alternative names:

# standard object properties & alternative names
default_properties = {
  :title           => [:name, :label],
  :type            => [:kind, :group, :class],
  :image           => [:picture, :photo],
  :url             => [:permalink, :link],
  :description     => [:info, :details],
  :site_name       => [:site],
  :latitude        => [:lat],
  :longitude       => [:lng],
  :street_address  => [:address],
  :locality        => [:locale, :area],
  :region          => [:province, :territory],
  :postal_code     => [:post_code, :zip_code, :zip],
  :country_name    => [:country],
  :email           => [:email_address],
  :phone_number    => [:phone],
  :fax_number      => [:fax]
}

Notes

This is my first gem so things are a bit rough around the edges, all feedback is happily welcomed :) - please fork/fix to your heart's content.

Project Goals

1. Find a way to provide model URLs using the url_for view/controller helpers.

2. Map common attribute names to og meta tags (e.g. title, description, image etc).

3. Provide helpers that allow resulting meta tags to be easily added to global layout in a standar Rails REST architecture. i.e. for all /show actions, add meta tags to head if object has open graph attributes.

4. Allow for easy configuration for constants such as fb:app_id & fb:admins as well as an app namespace to be used in og:type and any custom attributes.

5. Automatically handle arrays, i.e. :cast => ['Tom Cruise', 'Kelly McGillis', 'Val Kilmer'] becomes:

<meta property="my-app:cast" content="Tom Cruise" />
<meta property="my-app:cast" content="Kelly McGillis" />
<meta property="my-app:cast" content="Val Kilmer" />

6. Keep it unobtrusive! no heavy configuration in models, something simple, e.g.

class Movie < ActiveRecord::Base
  acts_as_graph_object :custom => [:director, :writer, :cast]
end

This would map all standard properties title, description, image, app_id etc along with the custom properties director, writer & cast.

7. Write proper tests and documentation!