Flask Framework Cookbook - Second Edition

How to do it...

Follow these steps to understand how signaling works:

1. First, create signals for the product and category creation. This can be done in my_app/catalog/models.py. This can be done in any file we want since signals are created on a global scope:

from blinker import Namespace 
 
catalog_signals = Namespace() 
product_created = catalog_signals.signal('product-created') 
category_created = catalog_signals.signal('category-created') 

We will use Namespace to create signals, which will create them in a custom namespace rather than in the global namespace, thereby helping with the clean management of signals. We created two signals, where the intent of both is clear by their names.

2. Then, we will create subscribers to these signals and ...