Creating a custom context processor

Sometimes, we might want to calculate or process a value directly in the templates. Jinja2 maintains a notion that the processing of logic should be handled in views and not in templates, and thus, it keeps the templates clean. A context processor becomes a handy tool in this case. We can pass our values to a method; this will then be processed in a Python method, and our resultant value will be returned. Therefore, we are essentially just adding a function to the template context (thanks to Python for allowing us to pass around functions just like any other object).

How to do it…

Let's say we want to show the descriptive name of the product in the format Category / Product-name:

@product_blueprint.context_processor:
def some_processor():
    def full_name(product):
        return '{0} / {1}'.format(product['category'], product['name'])
    return {'full_name': full_name}

A context is simply a dictionary...