Method _set_compat_spider

scrapy/middleware.py:70–80

(self, spider: Spider | None)

        raise ValueError(f"{type(self).__name__} has no known Spider instance.")

    def _set_compat_spider(self, spider: Spider | None) -> None:
        if spider is None or self.crawler is not None:
            return
        # printing a deprecation warning is the caller's responsibility
        if self._compat_spider is None:
            self._compat_spider = spider
        elif self._compat_spider is not spider:
            raise RuntimeError(
                f"Different instances of Spider were passed to {type(self).__name__}:"
                f" {self._compat_spider} and {spider}"
            )

    @classmethod
    @abstractmethod