+ def keep_web_url(uuid_or_pdh, file, opts)
+ munged_id = uuid_or_pdh.sub('+', '-')
+ fmt = {uuid_or_pdh: munged_id}
+
+ tmpl = Rails.configuration.keep_web_url
+ if Rails.configuration.keep_web_download_url and
+ (!tmpl or opts[:disposition] == 'attachment')
+ # Prefer the attachment-only-host when we want an attachment
+ # (and when there is no preview link configured)
+ tmpl = Rails.configuration.keep_web_download_url
+ elsif not Rails.configuration.trust_all_content
+ check_uri = URI.parse(tmpl % fmt)
+ if opts[:query_token] and
+ not check_uri.host.start_with?(munged_id + "--") and
+ not check_uri.host.start_with?(munged_id + ".")
+ # We're about to pass a token in the query string, but
+ # keep-web can't accept that safely at a single-origin URL
+ # template (unless it's -attachment-only-host).
+ tmpl = Rails.configuration.keep_web_download_url
+ if not tmpl
+ raise ArgumentError, "Download precluded by site configuration"
+ end
+ logger.warn("Using download link, even though inline content " \
+ "was requested: #{check_uri.to_s}")
+ end
+ end
+
+ if tmpl == Rails.configuration.keep_web_download_url
+ # This takes us to keep-web's -attachment-only-host so there is
+ # no need to add ?disposition=attachment.
+ opts.delete :disposition
+ end
+
+ uri = URI.parse(tmpl % fmt)
+ uri.path += '/' unless uri.path.end_with? '/'
+ if opts[:path_token]
+ uri.path += 't=' + opts[:path_token] + '/'
+ end
+ uri.path += '_/'
+ uri.path += URI.escape(file)
+
+ query = Hash[URI.decode_www_form(uri.query || '')]
+ { query_token: 'api_token',
+ disposition: 'disposition' }.each do |opt, param|
+ if opts.include? opt
+ query[param] = opts[opt]
+ end
+ end
+ unless query.empty?
+ uri.query = URI.encode_www_form(query)
+ end
+
+ uri.to_s
+ end
+