def url
      url = source_path.to_s.sub(/^#{Regexp.escape(self.class.path)}/, '')
      url = url.sub(/\..+$/, extension)
      url = File.join(self.class.url, url) unless url.starts_with? self.class.url
      url = url.dasherize
      url
    end
def url
      url = source_path.to_s.sub(/^#{Regexp.escape(self.class.path)}/, '')
      url = url.sub(/\..+$/, extension)
      url = File.join(self.class.url, url) unless url.starts_with? self.class.url
      url = url.dasherize
      url
    end
The url to the resource. This is created by swiching the base path
 of the source file with the base url.