OpenWISP Coding Conventions

README.md

OpenWISP Coding Conventions

Note: This document is a personal note where I add the unsaid coding conventions of the OpenWISP community. I usually find these while reviewing PRs of new contributors. Some of these are not hard rules but mere preferences, while some are the best practices adopted by the Python/Django community.

1. Accessing the app setting

Any setting which is related to an OpenWISP module should not be accessed from the django.conf.settings object. Rather, it should be accessed by importing the settings file from the module.

Example:

- # Instead of doing this 
- from django.conf import settings 
- critical_metrics = getattr(settings, 'OPENWISP_MONITORING_CRITICAL_METRICS') 
+ # Do this 
+ from openwisp_monitoring.checks import settings as app_settings 
+ critical_metrics = app_settings.CRITICAL_metrics

2. Connecting signals to signal receiver

OpenWISP prefers to use the Signal.connect in apps.py of the Django app to connect signals to receivers instead of using the @receiver decorator on the receiver function.

3. Don't use ObjectDoesNotExist

OpenWISP prefers to use the Model.DoesNotExist instead of the blanket django.core.exceptions.ObjectDoesNotExists.