Django Signals vs Callbacks: When to Use?

What are Django signals and how do they differ from callbacks?

Django signals are a way to allow decoupled applications to get notified when certain actions occur elsewhere in the application. Callbacks, on the other hand, are functions that are passed as arguments to other functions and are executed after a certain event. The main difference is that signals are more about event-driven programming, while callbacks are more about function execution order.

When should I use signals instead of callbacks?

You should use signals when you want to decouple your code and allow different parts of your application to communicate without being tightly linked. Use callbacks when you need to ensure a specific order of execution or when the logic is closely related.

Can you give me an example of using a signal in Django?

Sure! For example, you can use the post_save signal to perform an action right after a model instance is saved. You would connect a function to this signal that executes your desired logic.

Are there any performance considerations when using signals?

Yes, using signals can introduce some overhead, especially if you have many connected receivers. It's important to ensure that the signal handlers are efficient and not doing heavy processing.