scrapy/scrapy/addons.py

54 lines
1.9 KiB
Python

import logging
from typing import TYPE_CHECKING, Any, List
from scrapy.exceptions import NotConfigured
from scrapy.settings import Settings
from scrapy.utils.conf import build_component_list
from scrapy.utils.misc import create_instance, load_object
if TYPE_CHECKING:
from scrapy.crawler import Crawler
logger = logging.getLogger(__name__)
class AddonManager:
"""This class facilitates loading and storing :ref:`topics-addons`."""
def __init__(self, crawler: "Crawler") -> None:
self.crawler: "Crawler" = crawler
self.addons: List[Any] = []
def load_settings(self, settings: Settings) -> None:
"""Load add-ons and configurations from a settings object and apply them.
This will load the add-on for every add-on path in the
``ADDONS`` setting and execute their ``update_settings`` methods.
:param settings: The :class:`~scrapy.settings.Settings` object from \
which to read the add-on configuration
:type settings: :class:`~scrapy.settings.Settings`
"""
for clspath in build_component_list(settings["ADDONS"]):
try:
addoncls = load_object(clspath)
addon = create_instance(
addoncls, settings=settings, crawler=self.crawler
)
addon.update_settings(settings)
self.addons.append(addon)
except NotConfigured as e:
if e.args:
logger.warning(
"Disabled %(clspath)s: %(eargs)s",
{"clspath": clspath, "eargs": e.args[0]},
extra={"crawler": self.crawler},
)
logger.info(
"Enabled addons:\n%(addons)s",
{
"addons": self.addons,
},
extra={"crawler": self.crawler},
)