Merge pull request #454 from AvdN/warn_dict_retval3

views: warn if handle_request returns dict

lona/view_runtime.py

@@ -42,6 +42,7 @@
 from lona.connection import Connection
 from lona.request import Request
 from lona.routing import Route
+import lona.warnings
 
 # avoid import cycles
 if TYPE_CHECKING: # pragma: no cover
@@ -344,8 +345,16 @@ def start(self):
  self.send_view_start()
 
  # run view
+ handle_request_return_value = self.view.handle_request(self.request)
+ if isinstance(handle_request_return_value, dict):
+ lona.warnings.warn( # NOQA: G010
+ 'Deprecated use of dict as return value of method handle_request\n (see: https://lona-web.org/1.x/api-reference/views.html#response-objects)',
+ lona.warnings.DictResponseDeprecationWarning,
+ callee=self.view.handle_request,
+ )
+
  response = parse_view_return_value(
- return_value=self.view.handle_request(self.request),
+ return_value=handle_request_return_value,
  interactive=self.route and self.route.interactive,
  )
 

lona/warnings.py

@@ -0,0 +1,55 @@
+import warnings as orginal_warnings
+
+
+class ExtendedWarn:
+ warn = orginal_warnings.warn
+
+ def __call__(
+ self, message, category=None, stacklevel=1, source=None, callee=None,
+ ):
+ # Check if message is already a Warning object
+ if isinstance(message, Warning):
+ category = message.__class__
+ if callee:
+ assert stacklevel == 1
+ if category is not None:
+ filename = callee.__func__.__code__.co_filename
+ lineno = callee.__func__.__code__.co_firstlineno
+ message = ('callee', message, filename, lineno, category)
+ else:
+ stacklevel += 1
+ self.warn(message, category, stacklevel, source) # NOQA: G010
+
+
+warn = ExtendedWarn()
+orginal_warnings.warn = warn # type: ignore
+
+_original_formatwarning = orginal_warnings.formatwarning
+
+
+def _formatwarning_with_callee(message, category, filename, lineno, line):
+ try:
+ if (
+ not isinstance(message, str)
+ and isinstance(message.args[0], tuple)
+ and len(message.args[0]) == 5
+ and message.args[0][0] == 'callee'
+ ):
+ _, message, filename, lineno, category = message.args[0]
+ except Exception:
+ # show original e.g. when message is not a string,
+ # but has not .args attribute
+ pass
+ return _original_formatwarning(message, category, filename, lineno, line)
+
+
+orginal_warnings.formatwarning = _formatwarning_with_callee # type: ignore
+
+
+class DictResponseDeprecationWarning(PendingDeprecationWarning):
+ pass
+
+
+orginal_warnings.simplefilter(
+ 'once', category=DictResponseDeprecationWarning,
+)