django-signal-handler 0.1.1

A package for handling Django model signals.

Django Signal Handler Utility

This package provides a base class, SignalHandler, for simplifying the handling of Django model signals. It streamlines the process of responding to pre_save, post_save, pre_delete, and post_delete signals by categorizing them into more specific methods.

Installation

You can install this utility using pip:

pip install django-signal-handler

Usage

Create a subclass of SignalHandler:

import logging
from typing import Any

from django.db.models.signals import post_delete, post_save, pre_delete, pre_save

from signal_handler import SignalHandler
from your_app.models import MyModel

logger = logging.getLogger(__name__)

class MyModelSignalHandler(SignalHandler):
    def pre_save_new(self, instance: Any, **kwargs: Any) -> None:
        logger.info(f"Pre-save new: {instance}")
        # Add your logic here

    def post_save_new(self, instance: Any, **kwargs: Any) -> None:
        logger.info(f"Post-save new: {instance}")
        # Add your logic here

    def pre_save_update(self, instance: Any, **kwargs: Any) -> None:
        logger.info(f"Pre-save update: {instance}")
        # Add your logic here

    def post_save_update(self, instance: Any, **kwargs: Any) -> None:
        logger.info(f"Post-save update: {instance}")
        # Add your logic here

    def pre_delete(self, instance: Any, **kwargs: Any) -> None:
        logger.info(f"Pre-delete: {instance}")
        # Add your logic here

    def post_delete(self, instance: Any, **kwargs: Any) -> None:
        logger.info(f"Post-delete: {instance}")
        # Add your logic here

Connect the signal handlers to your model:

from django.dispatch import receiver
from your_app.models import MyModel

from .signal_handlers import MyModelSignalHandler

handler = MyModelSignalHandler()

@receiver(pre_save, sender=MyModel)
@receiver(post_save, sender=MyModel)
@receiver(pre_delete, sender=MyModel)
@receiver(post_delete, sender=MyModel)
def my_model_signals(sender, instance, **kwargs):
    handler.run(sender, instance, **kwargs)

Class Overview

SignalHandler

• run(sender: type, instance: Any, **kwargs: Any) -> None:
  • Determines the signal type and dispatches to the appropriate handler method.
• pre_save_new(instance: Any, **kwargs: Any) -> None:
  • Handler for pre_save signals when a new instance is being created.
• post_save_new(instance: Any, **kwargs: Any) -> None:
  • Handler for post_save signals when a new instance is created.
• pre_save_update(instance: Any, **kwargs: Any) -> None:
  • Handler for pre_save signals when an existing instance is being updated.
• post_save_update(instance: Any, **kwargs: Any) -> None:
  • Handler for post_save signals when an existing instance is updated.
• pre_delete(instance: Any, **kwargs: Any) -> None:
  • Handler for pre_delete signals.
• post_delete(instance: Any, **kwargs: Any) -> None:
  • Handler for post_delete signals.

Benefits

• Organization: Separates signal handling logic into distinct methods, improving code readability and maintainability.
• Clarity: Makes it clear which signal is being handled (new vs. update for save signals).
• Reusability: The base class can be extended for different models, reducing code duplication.
• Logging: Includes basic logging for unknown or missing signals.

Contributing

Contributions are welcome! Please feel free to submit pull requests or open issues.