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+# -*- coding: utf-8 -*-
+
+# Define here the models for your spider middleware
+#
+# See documentation in:
+# https://doc.scrapy.org/en/latest/topics/spider-middleware.html
+
+from scrapy import signals
+
+
+class WebGraterSpiderMiddleware(object):
+ # Not all methods need to be defined. If a method is not defined,
+ # scrapy acts as if the spider middleware does not modify the
+ # passed objects.
+
+ @classmethod
+ def from_crawler(cls, crawler):
+ # This method is used by Scrapy to create your spiders.
+ s = cls()
+ crawler.signals.connect(s.spider_opened, signal=signals.spider_opened)
+ return s
+
+ def process_spider_input(self, response, spider):
+ # Called for each response that goes through the spider
+ # middleware and into the spider.
+
+ # Should return None or raise an exception.
+ return None
+
+ def process_spider_output(self, response, result, spider):
+ # Called with the results returned from the Spider, after
+ # it has processed the response.
+
+ # Must return an iterable of Request, dict or Item objects.
+ for i in result:
+ yield i
+
+ def process_spider_exception(self, response, exception, spider):
+ # Called when a spider or process_spider_input() method
+ # (from other spider middleware) raises an exception.
+
+ # Should return either None or an iterable of Response, dict
+ # or Item objects.
+ pass
+
+ def process_start_requests(self, start_requests, spider):
+ # Called with the start requests of the spider, and works
+ # similarly to the process_spider_output() method, except
+ # that it doesn’t have a response associated.
+
+ # Must return only requests (not items).
+ for r in start_requests:
+ yield r
+
+ def spider_opened(self, spider):
+ spider.logger.info('Spider opened: %s' % spider.name)
+
+
+class WebGraterDownloaderMiddleware(object):
+ # Not all methods need to be defined. If a method is not defined,
+ # scrapy acts as if the downloader middleware does not modify the
+ # passed objects.
+
+ @classmethod
+ def from_crawler(cls, crawler):
+ # This method is used by Scrapy to create your spiders.
+ s = cls()
+ crawler.signals.connect(s.spider_opened, signal=signals.spider_opened)
+ return s
+
+ def process_request(self, request, spider):
+ # Called for each request that goes through the downloader
+ # middleware.
+
+ # Must either:
+ # - return None: continue processing this request
+ # - or return a Response object
+ # - or return a Request object
+ # - or raise IgnoreRequest: process_exception() methods of
+ # installed downloader middleware will be called
+ return None
+
+ def process_response(self, request, response, spider):
+ # Called with the response returned from the downloader.
+
+ # Must either;
+ # - return a Response object
+ # - return a Request object
+ # - or raise IgnoreRequest
+ return response
+
+ def process_exception(self, request, exception, spider):
+ # Called when a download handler or a process_request()
+ # (from other downloader middleware) raises an exception.
+
+ # Must either:
+ # - return None: continue processing this exception
+ # - return a Response object: stops process_exception() chain
+ # - return a Request object: stops process_exception() chain
+ pass
+
+ def spider_opened(self, spider):
+ spider.logger.info('Spider opened: %s' % spider.name)