Django: Can't update database properly - django

Question

models.py
class Post(models.Model):
user = models.ForeignKey(User, on_delete=models.CASCADE)
title = models.CharField(max_length=500, verbose_name='Title')
post = models.TextField(verbose_name='Post')
post_time = models.DateTimeField()
update_time = models.DateTimeField()
exists = models.BooleanField(default=True)
def __str__(self):
return self.title
def save(self, *args, **kwargs):
if not self.id:
self.post_time = timezone.now()
# self.exists = True
self.update_time = timezone.now()
return super(Post, self).save(*args, **kwargs)
class PostEditHistory(models.Model):
user = models.ForeignKey(User, on_delete=models.CASCADE)
post = models.ForeignKey(Post, on_delete=models.CASCADE)
title = models.CharField(max_length=500)
body = models.TextField()
edit_time = models.DateTimeField()
views.py
#login_required
def edit_post(request, username, post_id):
other_user = User.objects.get(username=username)
post = Post.objects.get(user=other_user.pk, pk=post_id)
prev_post = post
form = EditPostForm(data=request.POST or None, instance=post)
if form.is_valid():
PostEditHistory.objects.create(
user=request.user,
post=prev_post,
title=prev_post.title,
body=prev_post.post,
edit_time=prev_post.update_time
)
return redirect('single_post', username=username, post_id=post_id)
form.save()
context = {
'form': form
}
return render(request, 'blog_post/edit_post.html', context)
Before saving edited post, I'm trying to save the original post to PostEditHistory model. Every time a post is edited, it performs the same operations. But the code save the edited post to both Post and PostEditHistory model, and the original one gets lost. Help me to solve the problem.
Thanks in advance.

Answer 1

You are leaving of your function before use form.save()
return redirect('single_post', username=username, post_id=post_id)
form.save()
Change the position
form.save()
return redirect('single_post', username=username, post_id=post_id)
Suggestion: You should remove logic from views and handle it only in your models using functions...
Obs.: Dont use straight .objects.get() because if this do not exist will break your page and throw error, use filter to get the values without breaking and check it
class PostHistory(models.Model):
...
#staticmethod
def add_history(user, prev_post):
PostEditHistory.objects.create(
user=user,
post=prev_post,
title=prev_post.title,
body=prev_post.post,
edit_time=prev_post.update_time
)
#login_required
def edit_post(request, username, post_id):
...
post = Post.objects.filter(user=other_user.pk, pk=post_id).first()
prev_post = post if post else None
if form.is_valid():
PostEditHistory.add_history(request.user, prev_post)
form.save()
return redirect('single_post', username=username, post_id=post_id)