template.py 文件源码

def async_render_with_possible_json_value(self, value,
                                              error_value=_SENTINEL):
        """Render template with value exposed.

        If valid JSON will expose value_json too.

        This method must be run in the event loop.
        """
        self._ensure_compiled()

        variables = {
            'value': value
        }
        try:
            variables['value_json'] = json.loads(value)
        except ValueError:
            pass

        try:
            return self._compiled.render(variables).strip()
        except jinja2.TemplateError as ex:
            _LOGGER.error('Error parsing value: %s (value: %s, template: %s)',
                          ex, value, self.template)
            return value if error_value is _SENTINEL else error_value