It appears that not everyone knows that in python you can create classes dynamically without metaclasses. I'll show an example of how to do it.
So we've learned how to use custom QuerySet to chain requests:
Article.objects.old().public()Now we need to make it work for related objects:
user.articles.old().public()
This is done using use_for_related_fields, but it needs a little trick. Thing is that in django related managers are initialized without arguments, and our QuerySetManager takes argument - queryset class.
objects = QuerySetManager(MyQuerySet)We have to update QuerySetManager in such a way, that will allow setting queryset as class field:
class QuerySetManager(models.Manager):
use_for_related_fields = True
queryset_class = QuerySet
def get_query_set(self):
return self.queryset_class(self.model, using=self._db)
def __getattr__(self, key):
return getattr(self.get_query_set(), key)In order to use this manager, we have to create a sublcass and set queryset_class:
class MyManager(QuerySetManager):
queryset_class = MyQuerySetIt's not fun to create such class every time. So we'll write a function that does it for us:
def queryset_manager(qs_class):
class Manager(QuerySetManager):
queryset_class = qs_class
return Manager()Now it's enough to write:
objects = queryset_manager(MyQuerySet)Subscribe for the news and updates
This article explores Figma’s Dev Mode, a tool that streamlines design-to-code translation by enabling precise inspection, automated code generation, and seamless integration with design systems.
Tired of boring programming courses where you're forced to read thick textbooks and write code that's never used? Need a platform that makes learning fun and exciting? Then you're in the right place!
One of our ongoing projects, Neptyne, introduces an Excel-like grid written in React. We used a library to apply virtual scroll to it, but we stumbled upon a problem with fixed rows and columns inside the grid. Here I would like to describe this problem, how it occurs, and how we handled it.
In this beginners friends article I'll explain how to make authentication with Google account on your Django site and how to make authentication for you REST API.
We often handling API server updates including backwards-incompatible changes when upgrading web applications. At the same time we update the client part, therefore, we did not experience any particular difficulties.
In this article we will tell you about the basics of working with GraphQL in Angular 2 environment with detailed example.
