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
We have reviewed the top web frameworks for server and client-side development and compared their pros and cons. Find out which one can be a great fit for your next project.
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.
Protection of WEB App is of paramount importance and it should be afforded the same level of security as the intellectual rights or private property. I'm going to cover how to protect your web app.
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 VIM there is a command for char search: f. After first use it can be repeated with ;. I like to navigate in line with it. You see that you need to go to bracket in a middle of a line - you press f( and one-two ; and you are there. There's no such command in Emacs, so I had to write my own. I've managed even to implement repetition with ;.
In my current project I had a task to use twitter API. Twitter uses OAuth for authentication, which is pretty dreary. To avoid fiddling with it all the time, I've moved authentication to decorator. If key is available - nothing happens, just view is launched as usual. It's convenient that there's no need for additional twitter settings in user profile. Code is in article.