How to save the attribute of my ForeignKey? - django

Question

I am trying to create a view that allows users to upload their documents in my Lessons model. However when documents are uploaded, I am not able to save the instance in which the form is being submitted. When I access the admin page, the field for my ForeignKey is left empty.
This is the views.py for users to submit their documents:
class UploadLessonView(CreateView):
model = Lesson
fields = ['title', 'file']
template_name = 'store/upload_lesson.html'
success_url = '../'
def form_valid(self, form):
form.instance.author = self.request.user
return super(UploadLessonView, self).form_valid(form)
This is the models.py for my child model:
class Lesson(models.Model):
title = models.CharField(max_length=100)
file = models.FileField(upload_to="lesson/pdf")
date_posted = models.DateTimeField(default=timezone.now)
post = models.ForeignKey(Post, on_delete=models.CASCADE, null=True, blank=True)
def __str__(self):
return self.title
def get_absolute_url(self):
return reverse('lesson_upload', kwargs={'pk': self.pk})
For my parent model:
class Post(models.Model):
title = models.CharField(max_length=100)
image = models.ImageField(default = 'default0.jpg', upload_to='course_image/')
description = models.TextField()
price = models.DecimalField(decimal_places=2, max_digits=6)
date_posted = models.DateTimeField(default=timezone.now)
author = models.ForeignKey(User, on_delete=models.CASCADE)
rating = models.IntegerField(default = 0)
def __str__(self):
return self.title
def get_absolute_url(self):
return reverse('post-detail', kwargs={'pk' : self.pk})
Field for Post is left empty when I submit documents.

Answer 1

You are not setting the Post object in Lesson with the View. So you can fix it in two ways.
One way, is to send it via url, for example:
# url
url('lesson/<int:post_id>/create/', UploadLessionView.as_view())
And use the value of post_id in View:
class UploadLessonView(CreateView):
model = Lesson
fields = ['title', 'file']
template_name = 'store/upload_lesson.html'
success_url = '../'
def form_valid(self, form):
form.instance.post = get_object_or_404(Post, pk=self.kwargs.get('post_id'))
return super(UploadLessonView, self).form_valid(form)
Two, you can add post in fields:
class UploadLessonView(CreateView):
model = Lesson
fields = ['title', 'file', 'post'] # <-- Here
template_name = 'store/upload_lesson.html'