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     ).merge(
  14       properties.slice("article:published_time")
  15     )
  16
  17     safe_join(tags.map do |property, content|
  18       tag.meta(:property => property, :content => content)
  19     end, "\n")
  20   end
  21
  22   private
  23
  24   def opengraph_image_properties(properties)
  25     begin
  26       if properties["og:image"]
  27         image_properties = {}
  28         image_properties["og:image"] = Addressable::URI.join(root_url, properties["og:image"]).normalize
  29         image_properties["og:image:alt"] = properties["og:image:alt"] if properties["og:image:alt"]
  30         return image_properties
  31       end
  32     rescue Addressable::URI::InvalidURIError
  33       # return default image
  34     end
  35     {
  36       "og:image" => image_url("osm_logo_256.png"),
  37       "og:image:alt" => t("layouts.logo.alt_text")
  38     }
  39   end
  40 end