enabling logging for Flask

Author: dmalan

src/cs50/__init__.py

@@ -1,18 +1,14 @@
-import logging
 import os
 import sys
 
 try:
 
     # Save student's sys.path
-    path = sys.path[:]
+    _path = sys.path[:]
 
     # In case student has files that shadow packages
     sys.path = [p for p in sys.path if p not in ("", os.getcwd())]
 
-    # Disable logger by default
-    #logging.getLogger("cs50").disabled = True
-
     # Import cs50_*
     from .cs50 import get_char, get_float, get_int, get_string
     try:
@@ -29,4 +25,4 @@
 finally:
 
     # Restore student's sys.path (just in case library raised an exception that caller caught)
-    sys.path = path
+    sys.path = _path

src/cs50/flask.py

@@ -1,3 +1,5 @@
+import logging
+
 from distutils.version import StrictVersion
 from os import getenv
 from pkg_resources import get_distribution
@@ -8,8 +10,8 @@
 try:
 
     # Only patch >= 1.0
-    version = StrictVersion(get_distribution("flask").version)
-    assert version >= StrictVersion("1.0")
+    _version = StrictVersion(get_distribution("flask").version)
+    assert _version >= StrictVersion("1.0")
 
     # Reformat logger's exceptions
     # http://flask.pocoo.org/docs/1.0/logging/
@@ -20,19 +22,42 @@
     except:
         pass
 
+    # Enable logging when Flask is in use,
+    # monkey-patching own SQL module, which shouldn't need to know about Flask
+    logging.getLogger("cs50").disabled = True
+    try:
+        import flask
+        from .sql import SQL
+        _before = SQL.execute
+        def _after(*args, **kwargs):
+            disabled = logging.getLogger("cs50").disabled
+            if flask.current_app:
+                logging.getLogger("cs50").disabled = False
+            try:
+                _before(*args, **kwargs)
+            except:
+                logging.getLogger("cs50").disabled = disabled
+                raise
+            else:
+                logging.getLogger("cs50").disabled = disabled
+        SQL.execute = _after
+    except:
+        pass
+
     # Add support for Cloud9 proxy so that flask.redirect doesn't redirect from HTTPS to HTTP
     # http://stackoverflow.com/a/23504684/5156190
     if getenv("C9_HOSTNAME") and not getenv("IDE_OFFLINE"):
         try:
             import flask
             from werkzeug.contrib.fixers import ProxyFix
-            before = flask.Flask.__init__
-            def after(self, *args, **kwargs):
-                before(self, *args, **kwargs)
+            _before = flask.Flask.__init__
+            def _after(*args, **kwargs):
+                _before(*args, **kwargs)
                 self.wsgi_app = ProxyFix(self.wsgi_app)
-            flask.Flask.__init__ = after
+            flask.Flask.__init__ = _after
         except:
             pass
 
-except:
+except Exception as e:
+    print(e)
     pass

src/cs50/sql.py

@@ -64,12 +64,12 @@ def connect(dbapi_connection, connection_record):
             disabled = self._logger.disabled
             self._logger.disabled = True
             self.execute("SELECT 1")
+            self._logger.disabled = disabled
         except sqlalchemy.exc.OperationalError as e:
             e = RuntimeError(self._parse_exception(e))
             e.__cause__ = None
-            raise e
-        else:
             self._logger.disabled = disabled
+            raise e
 
     def execute(self, sql, *args, **kwargs):
         """Execute a SQL statement."""

tests/flask/application.py

@@ -5,12 +5,18 @@
 sys.path.insert(0, "../../src")
 
 import cs50
+import cs50.flask
 
 app = Flask(__name__)
 
+db = cs50.SQL("sqlite:///../sqlite.db")
+
 @app.route("/")
 def index():
+    db.execute("SELECT 1")
+    """
     def f():
         res = requests.get("cs50.harvard.edu")
     f()
+    """
     return render_template("index.html")

tests/sqlite.py

@@ -1,9 +1,12 @@
+import logging
 import sys
 
 sys.path.insert(0, "../src")
 
 from cs50 import SQL
 
+logging.getLogger("cs50").disabled = False
+
 db = SQL("sqlite:///sqlite.db")
 db.execute("SELECT 1")