Module: GeoblacklightAdmin::ImageService::IiifManifest

Defined in:
app/services/geoblacklight_admin/image_service/iiif_manifest.rb

Class Method Summary collapse

Class Method Details

.image_url(document, _size) ⇒ String

Formats and returns a thumbnail url from a IIIF Manifest

Parameters:

  • (SolrDocument)
  • thumbnail (Integer) —

    size

Returns:

  • (String) —

    iiif thumbnail url



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# File 'app/services/geoblacklight_admin/image_service/iiif_manifest.rb', line 56

def self.image_url(document, _size)
  tempfile = Down.download(document.viewer_endpoint)
  manifest_json = JSON.parse(tempfile.read)

  # Sequences - Return the first image if it exists
  # - best case option
  if manifest_json.dig("sequences", 0, "canvases", 0, "images", 0, "resource", "@id")
    Rails.logger.debug("\n Image: sequences \n")
    if manifest_json.dig("sequences", 0, "canvases", 0, "images", 0, "resource", "@id").include?("osu")
      Rails.logger.debug("\n Image: sequences - OSU variant \n")
      manifest_json.dig("sequences", 0, "canvases", 0, "images", 0, "resource", "service", "@id") + "/full/1000,/0/default.jpg"
    else
      manifest_json.dig("sequences", 0, "canvases", 0, "images", 0, "resource", "@id")
    end

  # Items - Return the first item image if it exists
  # - Northwestern
  elsif manifest_json.dig("items", 0, "items", 0, "items", 0, "body", "id")
    Rails.logger.debug("\n Image: items body id \n")
    manifest_json.dig("items", 0, "items", 0, "items", 0, "body", "id")

  # Items - Return the first item image if it exists
  # - strange option
  elsif manifest_json.dig("items", 0, "items", 0, "items", 0, "id")
    Rails.logger.debug("\n Image: items id \n")
    manifest_json.dig("items", 0, "items", 0, "items", 0, "id")

  # Thumbnail - Return the "thumbnail" if it exists
  # - varies in size depending on the provider
  # - worst case option really
  # - can be @id or id
  elsif manifest_json["thumbnail"]
    Rails.logger.debug("\n Image: thumbnail \n")
    if manifest_json.dig("thumbnail", "@id")
      manifest_json.dig("thumbnail", "@id")
    else
      manifest_json.dig("thumbnail", "id")
      manifest_json.dig("thumbnail", "id")
    end

  # Fail - Gonna fail
  else
    Rails.logger.debug("\n Image: failed \n")
    document.viewer_endpoint
  end
rescue => e
  Rails.logger.debug("\n Rescued: #{e.inspect} \n")
  document.viewer_endpoint
end