Add the Scrapy addon.

README.rst

@@ -42,7 +42,12 @@ Installation
 Configuration
 =============
 
-To enable this plugin:
+To enable this plugin, if your Scrapy version supports addons:
+
+-   Add ``"scrapy_zyte_api.ScrapyZyteAPIAddon"`` to the ``ADDONS`` setting with
+    any priority.
+
+Otherwise:
 
 -   Set the ``http`` and ``https`` keys in the `DOWNLOAD_HANDLERS
     <https://docs.scrapy.org/en/latest/topics/settings.html#std-setting-DOWNLOAD_HANDLERS>`_
@@ -62,13 +67,24 @@ To enable this plugin:
     Scrapy setting to
     ``"twisted.internet.asyncioreactor.AsyncioSelectorReactor"``.
 
+In both cases:
+
 -   Set `your Zyte API key
     <https://docs.zyte.com/zyte-api/usage/general.html#authorization>`_ as
     either the ``ZYTE_API_KEY`` Scrapy setting or as an environment variable of
     the same name.
 
 For example, in the ``settings.py`` file of your Scrapy project:
 
+.. code-block:: python
+
+    ADDONS = {
+        "scrapy_zyte_api.ScrapyZyteAPIAddon": 1,
+    }
+    ZYTE_API_KEY = "YOUR_API_KEY"
+
+or::
+
 .. code-block:: python
 
     DOWNLOAD_HANDLERS = {

scrapy_zyte_api/__init__.py

@@ -7,4 +7,5 @@
 
 from ._downloader_middleware import ScrapyZyteAPIDownloaderMiddleware  # NOQA
 from ._request_fingerprinter import ScrapyZyteAPIRequestFingerprinter  # NOQA
+from .addon import ScrapyZyteAPIAddon  # NOQA
 from .handler import ScrapyZyteAPIDownloadHandler  # NOQA

scrapy_zyte_api/addon.py

@@ -0,0 +1,24 @@
+from scrapy.settings import BaseSettings
+
+from scrapy_zyte_api import ScrapyZyteAPIDownloaderMiddleware
+
+
+class ScrapyZyteAPIAddon:
+    def update_settings(self, settings: BaseSettings) -> None:
+        settings["DOWNLOAD_HANDLERS"][
+            "http"
+        ] = "scrapy_zyte_api.ScrapyZyteAPIDownloadHandler"
+        settings["DOWNLOAD_HANDLERS"][
+            "https"
+        ] = "scrapy_zyte_api.ScrapyZyteAPIDownloadHandler"
+        settings["DOWNLOADER_MIDDLEWARES"][ScrapyZyteAPIDownloaderMiddleware] = 1000
+        settings.set(
+            "REQUEST_FINGERPRINTER_CLASS",
+            "scrapy_zyte_api.ScrapyZyteAPIRequestFingerprinter",
+            "addon",
+        )
+        settings.set(
+            "TWISTED_REACTOR",
+            "twisted.internet.asyncioreactor.AsyncioSelectorReactor",
+            "addon",
+        )

tests/__init__.py

@@ -1,18 +1,19 @@
 from contextlib import asynccontextmanager, contextmanager
 from os import environ
-from typing import Optional
+from typing import Any, Dict, Optional
 
 from scrapy import Spider
 from scrapy.crawler import Crawler
 from scrapy.utils.test import get_crawler as _get_crawler
 from zyte_api.aio.client import AsyncClient
 
+from scrapy_zyte_api.addon import ScrapyZyteAPIAddon
 from scrapy_zyte_api.handler import ScrapyZyteAPIDownloadHandler
 
 _API_KEY = "a"
 
 DEFAULT_CLIENT_CONCURRENCY = AsyncClient(api_key=_API_KEY).n_conn
-SETTINGS = {
+SETTINGS: Dict[str, Any] = {
     "DOWNLOAD_HANDLERS": {
         "http": "scrapy_zyte_api.handler.ScrapyZyteAPIDownloadHandler",
         "https": "scrapy_zyte_api.handler.ScrapyZyteAPIDownloadHandler",
@@ -21,6 +22,12 @@
     "ZYTE_API_KEY": _API_KEY,
     "TWISTED_REACTOR": "twisted.internet.asyncioreactor.AsyncioSelectorReactor",
 }
+SETTINGS_ADDON: Dict[str, Any] = {
+    "ADDONS": {
+        ScrapyZyteAPIAddon: 1,
+    },
+    "ZYTE_API_KEY": _API_KEY,
+}
 UNSET = object()
 
 
@@ -49,8 +56,10 @@ def get_download_handler(crawler, schema):
 
 
 @asynccontextmanager
-async def make_handler(settings: dict, api_url: Optional[str] = None):
-    settings = {**SETTINGS, **settings}
+async def make_handler(
+    settings: Dict[str, Any], api_url: Optional[str] = None, *, use_addon: bool = False
+):
+    settings = {**(SETTINGS if not use_addon else SETTINGS_ADDON), **settings}
     if api_url is not None:
         settings["ZYTE_API_URL"] = api_url
     crawler = get_crawler(settings)

tests/test_handler.py

@@ -430,3 +430,12 @@ def test_log_request_truncate_negative(enabled):
             settings=None,
             crawler=crawler,
         )
+
+
+@ensureDeferred
+async def test_addon(mockserver):
+    async with make_handler({}, mockserver.urljoin("/"), use_addon=True) as handler:
+        meta = {"zyte_api": {"foo": "bar"}}
+        request = Request("https://example.com", meta=meta)
+        await handler.download_request(request, None)
+        assert handler._stats.get_value("scrapy-zyte-api/success") == 1