'Extract on demand the help file resource'

def show_help(self):

    def get_help_file_resource():
        file_path = os.path.join(config_dir, u'plugins', HELPFILE_NAME)
        file_data = self.load_resources(HELPFILE_NAME)[HELPFILE_NAME]
        with open(file_path, u'w') as f:
            f.write(file_data)
        return file_path
    url = (u'file:///' + get_help_file_resource())
    open_url(QUrl(url))
