Django 3 Web Development Cookbook - Fourth Edition

How to do it...

Perform the following steps:

1. This is a pattern that you can use to cache a method return value of a model for repetitive use in views, forms, or templates, as follows:

class SomeModel(models.Model):    def some_expensive_function(self):        if not hasattr(self, "_expensive_value_cached"):            # do some heavy calculations...            # ... and save the result to result variable            self._expensive_value_cached = result        return self._expensive_value_cached

2. For example, let's create a get_thumbnail_url() method for the ViralVideo model. You will explore this in more detail later in the Using database query expressions recipe in Chapter 10, Bells and Whistles:

# myproject/apps/viral_videos/models.pyimport refrom django.db import modelsfrom django.utils.translation ...