exceptions-and-logging 0.0.2

A Django app for logging custom application errors

exceptions_and_logging

A Django app for logging custom application errors on the server side and also spits out JSON error info on the client side. You basically subclass our ApplicationErrors class and the rest is done for you.

Dependencies

• Django Rest Framework
• PyYaml

Installation

In your virtual environment run:

pip install exceptions-and-logging

Usage

1. Add exceptions_and_logging to your Django installed apps:

# settings.py

INSTALLED_APPS = [
    ...

    'exceptions_and_logging',
]

2. Without logging config.

# your_app.exceptions.py (or wherever your app exceptions are)

from exceptions_and_logging.exceptions import ApplicationErrors

class MyCustomException(ApplicationErrors):
    default_message = "This item: '%(item_name)s' isn't supposed to be null"

    def __init__(self, item_name):
        message = self.default_message % {"item_name": item_name}
        super().__init__(message)

When this error is raised:

• Generated response on the client side (via Rest Framework):

  • {
      "error":{
          "type":"MyCustomException",
          "message":"This item: 'SomeItem' isn't supposed to be null",
          "code":"error"
          }
    }
    

  • An HTTP 500 Application Error response is returned.

• Generated log on the server console (stdout):

  • 02/15/2021 04:30:34 PM - APPLICATION ERROR - ERROR
    Error Type: MyCustomException
    Error Message: This item: 'SomeItem' isn't supposed to be null
    Traceback (most recent call last):
      # Bunch of traceback info
      ...
      ...
        raise NullError("SomeItem")
    your_app.exceptions.MyCustomException: This item: 'SomeItem' isn't supposed to be null
    

3. With Logging Config

# your_app.exceptions.py (or wherever your app exceptions are)

from exceptions_and_logging.exceptions import ApplicationErrors

# Path to your logging config file
module_dir = os.path.dirname(__file__)
config_file = os.path.join(module_dir, "myconfig.yaml")

class MyCustomException(ApplicationErrors):
    default_message = "This item: '%(item_name)s' isn't supposed to be null"
    log_config = config_file 	# Can also be a dict config

    # If no logger name is passed, it will use the default logger name.
    def __init__(self, item_name, logger_name=None):
        message = self.default_message % {"item_name": item_name}
        super().__init__(message, logger_name=logger_name)

• The ApplicationError class provides hooks for adding extra format strings to the logging message and also extra key, value pairs for the error dict.

• # Assuming your formatter has extra values like user_id and user_email
  msg_format = '%(asctime)s - APPLICATION ERROR - %(levelname)s\n' \
               'User Email: %(user_email)s\n' \
      	     'User ID: %(user_id)s\n'\
               'Error Message: %(message)s\n'
  
  class MyCustomException(ApplicationErrors):
      def __init__(self, user_id, user_email, **err_dict_kwargs):
          self.user_id, self.user_email = user_id, user_email
          super().__init__(**err_dict_kwargs)
  
      # Override this method to return extra kwargs for logging
      def extra_kwargs(self) -> dict:
          dict_ = {
              "user_id": self.user_id,
              "user_email": self.user_email
          }
          return dict_
  

  # in views.py
  
  from rest_framework.views import APIView
  
  from .exceptions import MyCustomException
  
  class TestException(APIView):
  
      def get(self, request):
          raise MyCustomException(
          	"id4", "[e-mail]", foo="bar", hot="soup"
          	)
  

  Generated response on the client side via Rest Framework:

  {
      "error":{
          "type":"MyCustomException",
          "message":"An application error occurred.",
          "code":"error",
          "foo":"bar",
          "hot":"soup"
      }
  }