Styjun

At my django application users are able to buy specific posted elements. To later-on display a content_preview or the full content of a post i created a "helper_model" -> Post_Paid_Sell_Tut to check if a user has paid for the post or not. My target is that i can later on display the peview or full content accordingly to the paid or unpaid status but i dont clearly understand how to get those two models in relations at my views.py

i created the following two models for this:

PAYMENT_STATUS = (
(0, 'unpaid'),
(1, 'paid')
)

class Post_Paid_Sell_Tut(models.Model):
 paying_user = models.ForeignKey(User, on_delete=models.CASCADE)
 post_sell_tut = models.ForeignKey(Post_Sell_Tut, on_delete=models.CASCADE)
 STATUS = models.IntegerField(choices=PAYMENT_STATUS, default=0)
 paid_date = models.DateField(auto_now_add=True)

 def publish(self):
 self.paid_date = timezone.now()
 self.save()

 class Meta:
 ordering = ['-paid_date']



class Post_Sell_Tut(models.Model):
 author = models.ForeignKey(User, on_delete=models.CASCADE)
 title = models.CharField(max_length=40)
 content_preview = models.TextField(verbose_name="Tut Content Preview", max_length=500)
 content = EncryptedTextField(verbose_name="Tut Content", max_length=10000)
 .....

now i want to understand how i can bring those two models in relations at my views.py.
In the end the user will see a form with only a Buy button and some Text. after he hits the button the status should get changed from unpaid to paid for the paying user.

my current views.py (Updated)

def post_sell_tut_buy(request, pk):
 post = get_object_or_404(Post_Sell_Tut, pk=pk)
 if request.user == post.author:
 messages.error(request, 'You cannot buy POst(s) you created by your own!')
 return redirect('post_sell_tut_detail', pk=post.pk)
 else:
 template = 'Post_Sell_Tut/post_sell_tut_buy.html'
 context = 
 'post': post,
 
 return render(request, template, context)


def post_sell_tut_buy_exec(request, pk):
 post = get_object_or_404(Post_Sell_Tut, pk=pk)
 if request.user == post.author:
 messages.error(request, 'You cannot buy Post(s) you created by your own!')
 return redirect('post_sell_tut_detail', pk=post.pk)
 else:
 template = 'Post_Sell_Tut/post_sell_tut_buy.html'
 post.STATUS = 1
 post.save()
 context = 
 'post': post
 
 return render(request, template, context)

Do i really need a Form at this point?
and if so, how does it have to look like?

Thanks for help in adavance :)

First of all, you should change your status choices a little bit.

STATUSES = (
(0, 'unpaid'),
(1, 'paid')
)

class Post_Paid_Sell_Tut(models.Model):
 paying_user = models.ForeignKey(User, on_delete=models.CASCADE)
 post_sell_tut = models.ForeignKey(Post_Sell_Tut, on_delete=models.CASCADE)
 STATUS = models.IntegerField(choices=STATUSES, default=0)

This will ease later database searches and will clarify the issues. Then if you are just updating the status then there is no need for any form.

def post_sell_tut_buy(request, pk):
 post = get_object_or_404(Post_Sell_Tut, pk=pk)
 if request.user == post.author:
 messages.error(request, 'You cant buy your own Post!')
 return redirect('post_sell_tut_detail', pk=pk)
 else:
 template = 'Post_Sell_Tut/post_sell_tut_buy.html'
 post.STATUS = 1 # You are updating the STATUS
 post.save() # you are writing the change to database
 context = 
 'post': post
 
 return render(request, template, context)

In addition by passing post instance to the template you are desired to view the informations you should follow this:

def post_sell_tut_buy(request, pk):
 post = Post_Paid_Sell_Tut.objects.select_related('post_sell_tut').filter(pk=pk)
 if request.user == post.author:
 messages.error(request, 'You cant buy your own Post!')
 return redirect('post_sell_tut_detail', pk=pk)
 else:
 template = 'Post_Sell_Tut/post_sell_tut_buy.html'
 post.STATUS = 1 # You are updating the STATUS
 post.save() # you are writing the change to database
 context = 
 'post': post
 
 return render(request, template, context)

I added select_related because when you try to fetch information by the foreign key in from post it will not cause an extra DB request.

UPDATE

def post_sell_tut_buy(request, pk):
 post = Post_Sell_Tut.objects.select_related('author).filter(pk=pk)
 if request.user == post.author:
 messages.error(request, 'You cannot buy POst(s) you created by your own!')
 return redirect('post_sell_tut_detail', pk=post.pk)
 else:
 template = 'Post_Sell_Tut/post_sell_tut_buy.html'
 context = 
 'post': post,
 
 return render(request, template, context)

You cannot access STATUS from Post_Sell_Tut model. It does not have that field.

def post_sell_tut_buy_exec(request, pk):
 post_sell_tut = get_object_or_404(Post_Sell_Tut, pk=pk)
 post_paid_sell_tut = Post_Paid_Sell_Tut.objects.filter(post_sell_tut=post_sell_tut)
 if request.user == post.author:
 messages.error(request, 'You cannot buy Post(s) you created by your own!')
 return redirect('post_sell_tut_detail', pk=post.pk)
 else:
 template = 'Post_Sell_Tut/post_sell_tut_buy.html'
 post_paid_sell_tut.STATUS = 1
 post_paid_sell_tut.save()
 context = 
 'post': post
 
 return render(request, template, context)

just create a "Post_Paid_Sell_Tut" object when a user requests to buy a post

 def post_sell_tut_buy(request, pk):
 post = get_object_or_404(Post_Sell_Tut, pk=pk)
 if request.user == post.author:
 messages.error(request, 'You cant buy your own Post!')
 return redirect('post_sell_tut_detail', pk=post.pk)
 else:
 try:
 # throws an exception if not bought yet
 Post_Paid_Sell_Tut.get(paying_user=request.user, post_sell_tut=post) 
 messages.success(request, 'you allready have this post!')
 # ... other stuff

 except Post_Paid_Sell_Tut.DoesNotExist:
 # create Post_Paid_Sell_Tut object indicating that the user bought the post
 ppst = Post_Paid_Sell_Tut(paying_user=request.user,
 post_sell_tut=post, status="paid")
 ppst.save()
 messages.success(request, 'post is yours :)!')
 # ... other stuff