app/helpers/open_graph_helper.rb

   1 module OpenGraphHelper
   2   require "addressable/uri"
   3
   4   def opengraph_tags(title, properties)
   5     tags = {
   6       "og:site_name" => t("layouts.project_name.title"),
   7       "og:title" => title || t("layouts.project_name.title"),
   8       "og:type" => "website",
   9       "og:url" => url_for(:only_path => false),
  10       "og:description" => properties["og:description"] || t("layouts.intro_text")
  11     }.merge(
  12       opengraph_image_properties(properties)
  13     )
  14
  15     safe_join(tags.map do |property, content|
  16       tag.meta(:property => property, :content => content)
  17     end, "\n")
  18   end
  19
  20   private
  21
  22   def opengraph_image_properties(properties)
  23     begin
  24       if properties["og:image"]
  25         image_properties = {}
  26         image_properties["og:image"] = Addressable::URI.join(root_url, properties["og:image"]).normalize
  27         image_properties["og:image:alt"] = properties["og:image:alt"] if properties["og:image:alt"]
  28         return image_properties
  29       end
  30     rescue Addressable::URI::InvalidURIError
  31       # return default image
  32     end
  33     {
  34       "og:image" => image_url("osm_logo_256.png"),
  35       "og:image:alt" => t("layouts.logo.alt_text")
  36     }
  37   end
  38 end