Add LogFormatter.error method

scrapy/core/scraper.py

@@ -231,9 +231,9 @@ class Scraper(object):
                     signal=signals.item_dropped, item=item, response=response,
                     spider=spider, exception=output.value)
             else:
-                logger.error('Error processing %(item)s', {'item': item},
-                             exc_info=failure_to_exc_info(output),
-                             extra={'spider': spider})
+                logkws = self.logformatter.error(item, ex, response, spider)
+                logger.log(*logformatter_adapter(logkws), extra={'spider': spider},
+                           exc_info=failure_to_exc_info(output))
                 return self.signals.send_catch_log_deferred(
                     signal=signals.item_error, item=item, response=response,
                     spider=spider, failure=output)

scrapy/logformatter.py

@@ -8,6 +8,7 @@ from scrapy.utils.request import referer_str
 SCRAPEDMSG = u"Scraped from %(src)s" + os.linesep + "%(item)s"
 DROPPEDMSG = u"Dropped: %(exception)s" + os.linesep + "%(item)s"
 CRAWLEDMSG = u"Crawled (%(status)s) %(request)s%(request_flags)s (referer: %(referer)s)%(response_flags)s"
+ERRORMSG = u"'Error processing %(item)s'"
 
 
 class LogFormatter(object):
@@ -92,6 +93,16 @@ class LogFormatter(object):
             }
         }
 
+    def error(self, item, exception, response, spider):
+        """Logs a message when an item causes an error while it is passing through the item pipeline."""
+        return {
+            'level': logging.ERROR,
+            'msg': ERRORMSG,
+            'args': {
+                'item': item,
+            }
+        }
+
     @classmethod
     def from_crawler(cls, crawler):
         return cls()