Let's say I have such model class Event(models.Model) users_count = models.IntegerField(default=0) users = models.ManyToManyField(User) How would you recommend to update users_count value if Event add/delete some users ? ...
I am adding date_added and date_modified fields to a bunch of common models in my current project. I am subclassing models.Model and adding the appropriate fields, but I want to add automated save behavior (i.e: evey time anyone calls MyModel.save(), the date_modified field gets updated. I see two approaches: overriding the save() method...
I have a tough time understanding how signals work into my application (and how they work period). These are three areas where I assume they would apply (with my current knowledge): 1) Send XML to a remote server for reporting (after a transaction is complete). 2) Re size an image and upload the thumbnail to S3 after a user uploads it. ...
I need make a save with a model but i need disconnect some receivers of the signals before save it. I mean, I have a model: class MyModel(models.Model): ... def pre_save_model(sender, instance, **kwargs): ... pre_save.connect(pre_save_model, sender=MyModel) and in another place in the code i need something like: a = MyMo...
Hi, I'm trying to do something like these proposed signal decorators. In addition to having a decorator that connects the decorated method to a signal (with the signal's sender as an argument to the decorator), I would like to use the decorator on class methods. I'd like to use the decorator like so: class ModelA(Model): @connec...
Hello I have added a signal to my model, which sends email to some email addresses once a model is saved (via models.signals.post_save.connect signal and send_mail for email sending). This idea still makes delay for the users, when they save the model at the site, they have to wait until all those emails are sent and thats when they re...
the docs says: post_save django.db.models.signals.post_save created A boolean; True if a -new- record was create. and I have this: from django.db.models.signals import post_save def handle_new_user(sender, instance, created, **kwargs): print "--------> save() "+str(created) post_save.connect(handle_new_user, sender=User) when ...
Django models generally handle the ON DELETE CASCADE behaviour quite adequately (in a way that works on databases that don't support it natively.) However, I'm struggling to discover what is the best way to override this behaviour where it is not appropriate, in the following scenarios for example: ON DELETE RESTRICT (i.e. prevent del...
Hello, This is my first time working with django signals and I would like to hook the "comment_was_flagged" signal provided by the comments app to notify me when a comment is flagged. This is my code, but it doesn't seem to work, am I missing something? from django.contrib.comments.signals import comment_was_flagged from django.core...
I have an abstract model that keeps an on-disk cache. When I delete the model, I need it to delete the cache. I want this to happen for every derived model as well. If I connect the signal specifying the abstract model, this does not propagate to the derived models: pre_delete.connect(clear_cache, sender=MyAbstractModel, weak=False) ...
In Django I calculate the breadcrumb (a list of fathers) for an geographical object. Since it is not going to change very often, I am thinking of pre calculating it once the object is saved or initialized. 1.) What would be better? Which solution would have a better performance? To calculate it at _init_ or to calculate it when the obje...
Hi, I have extended Django's User Model using a custom user profile called UserExtension. It is related to User through a unique ForeignKey Relationship, which enables me to edit it in the admin in an inline form! I'm using a signal to create a new profile for every new user: def create_user_profile(sender, instance, created, **kwargs):...
I have found here on stackoverflow a solution to extend django-registration with new fields using signals. Here's the link : http://dmitko.ru/?p=546 . I have created extended profile model, extended form, added required options to settings , defined urls and the proper form is displayed but only normal User (from auth module) is created....
I have an extended UserProfile for registering new users. My user_created function connects to signals sent upon registering basic User instance and creates new UserProfile with extended fields from my form. Here's the code : from registration.signals import user_registered from accounts.forms import ExtendedRegistrationForm import ac...
I have found here on stackoverflow a method to extend django's built-in authentication using signals. My base User is defined by 'email' and passwords (so no username there). So I'm trying to modify it to my needs, but I'm geting a validation error for my form. Strange thing is that error is connected to the User.email field and I'm gett...
When an update/create is performed on a Django model (.save()) I would like to be able to "step in" and compare some particular attributes to what they were set to previously (if they previously existed at all). I'm thinking Pre-Save Signals, with a look-up to the original model doing a .objects.get(instance.id), but that feels wastefu...
Hello! I'm building an app that notifies user when new ThreadedComments appear. For this I'm using post_save signal. Here's my models.py: from django.db import models from django.contrib.auth.models import User from django.contrib.contenttypes.models import ContentType from django.contrib.contenttypes import generic from datetime impor...
I have a model class "Action" that get's extended by several other classes. I am new to django and assumed that if I called pre_save.connect(actionFunc, sender=Action) that actionFunc would get called anytime the save method in the Action class was called (including by any derived class). My observation is that this function only ge...
I'm about to create a site that has monitored registration in that only certain people are allowed to register. Undoubtedly some misfits will register despite any writing I put above the registration form so we're going with moderation. Upon registration a django.contrib.auth User and profile will be created and an email will be sent to...
Is there way to make custom signal when ManyToMany relations created? ...