def get_js(self):
        """ Fetches and returns javascript file path or contents, depending if
            we want a standalone presentation or not.
        """
        js_file = os.path.join(self.theme_dir, 'js', 'slides.js')

        if not os.path.exists(js_file):
            js_file = os.path.join(THEMES_DIR, 'default', 'js', 'slides.js')

            if not os.path.exists(js_file):
                raise IOError(u"Cannot find slides.js in default theme")
        with codecs.open(js_file, encoding=self.encoding) as js_file_obj:
            return {
                'path_url': utils.get_path_url(js_file, self.relative),
                'contents': js_file_obj.read(),
            }
Fetches and returns javascript file path or contents, depending if
            we want a standalone presentation or not.