Always log now, even if debug is off.

flask/logging.py

@@ -11,7 +11,24 @@
 
 from __future__ import absolute_import
 
-from logging import getLogger, StreamHandler, Formatter, getLoggerClass, DEBUG
+from logging import getLogger, StreamHandler, Formatter, getLoggerClass, \
+     DEBUG, ERROR
+
+
+PROD_LOG_FORMAT = '[%(asctime)s] %(levelname)s in %(module)s: %(message)s'
+DEBUG_LOG_FORMAT = (
+    '-' * 80 + '\n' +
+    '%(levelname)s in %(module)s [%(pathname)s:%(lineno)d]:\n' +
+    '%(message)s\n' +
+    '-' * 80
+)
+
+
+def should_log_for(app, mode):
+    policy = app.config['LOGGER_HANDLER_POLICY']
+    if policy == mode or policy == 'always':
+        return True
+    return False
 
 
 def create_logger(app):
@@ -30,16 +47,28 @@ def create_logger(app):
             return Logger.getEffectiveLevel(x)
 
     class DebugHandler(StreamHandler):
-        def emit(x, record):
-            StreamHandler.emit(x, record) if app.debug else None
+        def emit(self, record):
+            if app.debug and should_log_for(app, 'debug'):
+                StreamHandler.emit(self, record)
+
+    class ProductionHandler(StreamHandler):
+        def emit(self, record):
+            if not app.debug and should_log_for(app, 'production'):
+                StreamHandler.emit(self, record)
+
+    debug_handler = DebugHandler()
+    debug_handler.setLevel(DEBUG)
+    debug_handler.setFormatter(Formatter(DEBUG_LOG_FORMAT))
+
+    prod_handler = ProductionHandler()
+    prod_handler.setLevel(ERROR)
+    prod_handler.setFormatter(Formatter(PROD_LOG_FORMAT))
 
-    handler = DebugHandler()
-    handler.setLevel(DEBUG)
-    handler.setFormatter(Formatter(app.debug_log_format))
     logger = getLogger(app.logger_name)
     # just in case that was not a new logger, get rid of all the handlers
     # already attached to it.
     del logger.handlers[:]
     logger.__class__ = DebugLogger
-    logger.addHandler(handler)
+    logger.addHandler(debug_handler)
+    logger.addHandler(prod_handler)
     return logger