I'm having trouble wrapping my head around this. Right now I have some models that looks kind of like this: def Review(models.Model) ...fields... overall_score = models.FloatField(blank=True) def Score(models.Model) review = models.ForeignKey(Review) question = models.TextField() grade = models.IntegerField() A ...
I have a pretty generic Article model, with m2m relation to Tag model. I want to keep count of each tag usage, i think the best way would be to denormalise count field on Tag model and update it each time Article being saved. How can i accomplish this, or maybe there's a better way? ...
In a Django App I'm working on I've got this going on: class Parent(models.Model): name = models.CharField(...) def num_children(self): return Children.objects.filter(parent=self).count() def avg_child_rating(self): return Child.objects.filter(parent=self).aggregate(Avg('rating')) class Child(models.Model)...
One of the functionalities in a Django project I am writing is sending a newsletter. I have a model, Newsletter and a function, send_newsletter, which I have registered to listen to Newsletter's post_save signal. When the newsletter object is saved via the admin interface, send_newsletter checks if created is True, and if yes it actually...
I wrote some smart generic counters and managers for my models (to avoid select count queries etc.). Therefore I got some heavy logic going on for post_save. I would like to prevent handling the signal when there's no need to. I guess the perfect interface would be: instance.save(dispatch_signal=False) How can I accomplish this? ...
From what I can tell, in Python and and Django, signals are simply delegated events. Is there anything that functionally differentiates them from the typical notion of events in C#, Java, ActionScript, etc? ...
Hello! I have made a function that connects to a models 'pre_save' signal. Inside the function I am trying to check if the model instance's pk already exists in the table with: sender.objects.get(pk=instance._get_pk_val()) The first instance of the model raises an error. I catch the error and generate a slug field from the title. In a...
I realize this has been asked before, but I wasn't able to find a question that really dealt with what I'm trying to do. I think it's pretty simple, but I'd like to know what the general population thinks is best form here. Lets say we have the following: models.py class TestClass(models.Model): user = models.ForeignKey(User) ...
Does anyone know of a way to do something similar to Django's signals using LINQ to SQL? I'm trying to record when new rows are inserted and when certain columns are updated, so I really just want pre_save and post_save signals. I can kind of do it with some models by using the partials defined like OnFooIDChanging() and OnFooIDChanged...
Is there a way to see which signals have been set in Django? ...
The Django docs say this on the subject: Note also that Django stores signal handlers as weak references by default, so if your handler is a local function, it may be garbage collected. To prevent this, pass weak=False when you call the signal’s connect(). I haven't been able to find any justification for why this is the ...
I've defined a signal handler function in my models.py file. At the bottom of that file, I use signals.post_save.connect(myhandler, sender=myclass) as recommended in the docs at http://docs.djangoproject.com/en/dev/topics/signals/. However, when I run the test server, simple print-statement debugging shows that the models.py file gets i...
Im trying to connect a "Information" object to many "Customers" (see code below) When one Information object is updated, I want to send email to each Customer that is connected to the Information. However, when I log the sold_to field that the signal recieves I always get what the data is like BEFORE the save. I'm guessing this is bec...
How does one perform the following (Django 0.96) dispatcher hooks in Django 1.0? import django.dispatch.dispatcher def log_exception(*args, **kwds): logging.exception('Exception in request:') # Log errors. django.dispatch.dispatcher.connect( log_exception, django.core.signals.got_request_exception) # Unregister the rollback event...
I've got a URLs pattern like this: urlpatterns = ( url(r'^$', list_titles, name='list'), url(r'^(?P<tag>[a-z\-0-9]+?)/$', list_titles, name='filtered-list'), url(r'^(?P<title>\S+?)/$', show_title, name='title'), ) The filtered-list and title match the same things. If there is is a available list of things matching the tag...
I have a situation where I want to offload an xml fragment (an atom event) each time a model instance is saved, updated or deleted. The fragment needs to include information about related objects. I can't find an event that lets me use information from related objects after saving my object. The post_save signal seems o be triggered bef...
I'm working with Django signals, but they seem to be received twice, even if emitted once. Here's the code I'm working with (it's a simple wrapper to use Uploadify with Django)... # Signal-emitting code... emits whenever a file upload is received # ---------------------------------------------------------------- upload_recieved = djang...
I have a Django Model with a text field. I would like to modify the content of the text field before it's presented to the user in Django Admin. I was expecting to see signal equivalent of post_load but it doesn't seem to exist. To be more specific: I have a text field that takes user input. In this text field there is a read more sep...
Django is sending the pre/post_delete signals if you are using the queryset.delete() method, but shouldn't it then also send pre/post_save on queryset.update()? ...
I'm having issues with ManytoMany Relationships that are not updating in a model when I save it (via the admin) and try to use the new value within a function attached to the post_save signal or within the save_model of the associated AdminModel. I've tried to reload the object within those functions by using the get function with the id...