Develop Reference

Django user subscribe user relation

I`m creating a simple blog now, and the main problem is to create a relation between Users. I use a default django User which should subscribe another user who is an author of post.
I have only one Post model in my app
class Post(models.Model):
author = models.ForeignKey(User, on_delete=models.CASCADE, null=True)
title = models.CharField(max_length=128)
content = models.TextField(blank=True)
created_on = models.DateTimeField(auto_now_add=True)
seen = models.ManyToManyField(User, related_name='blog_posts', blank=True)

The relationship you're referring to isn't about the Post model as I understand it. So I think it might be better if you create a separate model. I share a model below as an idea, you can edit field names or add/delete fields according to your needs.
class AuthorSubscription(models.Model):
author = models.OneToOneField(User, on_delete=models.CASCADE, 'author_subscription')
subscribers = models.ManyToManyField(User, related_name='subscriptions', blank=True)
created_at = models.DateTimeField(auto_now_add=True)
updated_at = models.DateTimeField(auto_now=True)

Django form: reference fields from foreign key

I'm making a task tracker webapp (the full source code is also available) and I have a database structure where each task has a title, a description, and some number of instances, that can each be marked incomplete/incomplete:
class Task(models.Model):
title = OneLineTextField()
description = models.TextField(blank=True)
class TaskInstance(models.Model):
task = models.ForeignKey(Task, on_delete=models.CASCADE)
is_complete = models.BooleanField()
The task and the instances can be shared separately, although access to the instance should imply read access to the task. This is intended for classroom situations, where the teacher creates a task and assigns it to their students.
class TaskPermission(models.Model):
task = models.ForeignKey(Task, on_delete=models.CASCADE, related_name='permissions')
user = models.ForeignKey(User, on_delete=models.CASCADE, related_name='task_permissions_granted')
shared_by = models.ForeignKey(User, on_delete=models.PROTECT, null=True, related_name='task_permissions_granting')
can_edit = models.BooleanField(default=False)
class Meta:
unique_together = 'task', 'user', 'shared_by',
class TaskInstancePermission(models.Model):
task_instance = models.ForeignKey(TaskInstance, on_delete=models.CASCADE, related_name='permissions')
user = models.ForeignKey(User, on_delete=models.CASCADE, related_name='task_instance_permissions_granted')
shared_by = models.ForeignKey(User, on_delete=models.PROTECT, null=True, related_name='task_instance_permissions_granting')
can_edit = models.BooleanField(default=False)
class Meta:
unique_together = 'task_instance', 'user', 'shared_by',
My question is how to create a form for TaskInstances with fields for its is_complete, as well as its Task's title and description. Would something like this work? Or would I need to implement my own save and clean methods?
class TaskForm(ModelForm):
class Meta:
model = TaskInstance
fields = ('is_complete', 'task__title', 'task__description')

I think inlineformset_factory is what I'm looking for!
Actually, it does not seem to be useful: it is for multiple forms of the same type, not different types...

Django follow feature with m2m

I tried to solve the problem and got stuck. The problem is that I have a post that I can follow. My problem is that I don't know how to add a tracking button. Should this be done by url, with a view? Or should it be rather as a method in the model?
My problem is also whether it is properly written in terms of models - using the intermediate model Follower?
Here is Post model and I would like to add followers here. I mean, everybody who is interested, can follow this post.
class Post(models.Model):
owner = models.ForeignKey(settings.AUTH_USER_MODEL, on_delete=models.CASCADE, related_name='posts')
title = models.CharField(max_length=255, unique=True)
description = models.TextField(max_length=1024)
followers = models.ManyToManyField(settings.AUTH_USER_MODEL, through='Follower', blank=True)
is_visible = models.BooleanField(default=True)
created = models.DateTimeField(auto_now_add=True)
updated = models.DateTimeField(auto_now=True)
def __str__(self):
return self.title
def get_absolute_url(self):
return reverse('posts:post_detail', kwargs={'pk': self.pk})
def number_of_followers(self):
return self.followers.count()
Here is my manager for follower model:
class FollowerManager(models.Manager):
use_for_related_fields = True
def follow(self, user, pk):
post_object = get_object_or_404(Post, pk=pk)
if user.is_authenticated():
if user in post_object.followers.all():
Follower.objects.filter(post=post_object, user=user).delete()
else:
Follower.objects.create(post=post_object, user=user)
Here is Follower model:
class Follower(models.Model):
user = models.ForeignKey(settings.AUTH_USER_MODEL, on_delete=models.CASCADE)
post = models.ForeignKey(Post, on_delete=models.CASCADE)
created = models.DateTimeField(auto_now_add=True)
updated = models.DateTimeField(auto_now=True)
objects = FollowerManager()

Interactions between a user's browser and the database can only be done via a URL and a view. That view might call a model method, but there is no possible way for the browser to call that method directly.
(Also I don't understand what you're doing in the manager. Why are you deleting followers if the user is authenticated? Note that will always be true, so the followers will always be deleted.)

ValueError at /app/recomment/1/

I got an error,ValueError at /app/recomment/1/
Cannot assign "": "ReComment.target" must be a "POST" instance.The error is happened when I put Recomment button.I wanna make a page which is shown comment&recomment.I wrote codes
in models.py
class POST(models.Model):
title = models.CharField(max_length=100)
created_at = models.DateTimeField(auto_now_add=True)
class Comment(models.Model):
name = models.CharField(max_length=100, blank=True)
target = models.ForeignKey(POST, on_delete=models.CASCADE)
created_at = models.DateTimeField(auto_now_add=True, null=True)
class ReComment(models.Model):
name = models.CharField(max_length=100, blank=True)
target = models.ForeignKey(POST, on_delete=models.CASCADE)
created_at = models.DateTimeField(auto_now_add=True, null=True)
I cannot understand the error message's meaning that is I should put POST into obj.target = comment in place of comment in views.py.The variable of comment is send via POST,so I think this is POST instance.I cannot understand the difference of POST instance and normal instance.What is wrong in my code?How should I fix this?

Do something like this and check that to not forget anything.
class DetailView(generic.DetailView):
model = POST <<<<-------- error give true model here
template_name = 'detail.html'

How to make relation between one model to another two models

I am creating simple forum site using Django framework, and I've created comment model, at this moment my comment model has OneToOne relation with Post, it means that every moment belong to specific post, but there is also another feature that I want to provide. Every comment model should has possibility to be related to Post object OR to Answer model. Answer model it is just as in Stack Overflow, you add a Post and another user can add an answer to it. I want to mention that answer is too related with Post with OneToOne relation I think it will be sufficient and dosen't need edition.
Summarizing: How to allow adding comments to Post object or Answer object?
Also I want to say that I was considering creating two comments models, namely PostComment, and AnswerComment but I've got a conclusion that is really bad solution.
class Post(models.Model):
subject = models.CharField(max_length=100)
description = models.TextField(null=True)
section = models.ForeignKey(Section, on_delete=models.CASCADE, null=True)
author = models.ForeignKey(User, null=True, blank=True)
created_date = models.DateTimeField(default=timezone.now)
published_date = models.DateTimeField(blank=True, null=True)
slug = models.SlugField(max_length=100, null=True)
active = models.BooleanField(default=True)
def __str__(self):
return self.subject
def publish(self):
self.published_date = timezone.now()
self.save()
def close(self):
self.active = False
self.save()
class Comment(models.Model):
content = models.CharField(max_length=600)
post = models.OneToOneField(Post, on_delete=models.CASCADE)
author = models.ForeignKey(User, null=True, blank=True)
published_date = models.DateTimeField(blank=True, null=True)
def publish(self):
self.published_date = timezone.now()
self.save()
def __str__(self):
return "Comment to post: {0} added by {1} at {2}.".format(self.post.subject, self.author, self.published_date)
class Answer(models.Model):
content = models.TextField()
post = models.OneToOneField(Post, on_delete=models.CASCADE)
author = models.ForeignKey(User, null=True, blank=True)
published_date = models.DateTimeField(blank=True, null=True)
def publish(self):
self.published_date = timezone.now()
self.save()
def __str__(self):
return "Answer to post: {0} added by {1} at {2}.".format(self.post.subject, self.author, self.published_date)

Answer can be associated to only one post, so one to one
comment can only be associated with one post, so one to one
comment can only be associated with one answer, so one to one
Remember that the order of classes matters in Python. Place the comment class at the end, so that you can create one to one relationships between both Post and Answer. In the current position you can only do it with Post.
class Post(models.Model):
##
class Answer(models.Model):
##
class Comment(models.Model):
post = models.OneToOneField(Post, on_delete=models.CASCADE, null=True, blank=True)
answer = models.OneToOneField(Answer, on_delete=models.CASCADE, null=True, blank=True)

If one Post object can have several comments, I think you need ForeignKey in your comment field. About Answer, maybe you can add another field to your comment pointing to the object Answer which is related, with a ForeignKey if several comments are permited for an answer.