Issues Saving Django ModelForms with m2m Relations - django

Question

I'm trying to use Django ModelForms to allow teachers to schedule weekly classes with students. However, whenever I save a new instance of the weekly class from the modelform the m2m relations (students and teachers) are not saved.
I've looked pretty extensively in the Django documentation and tried everything to remedy this including setting commit=False on the save method and then using the save_m2m method. No dice.
Here's my code
models.py
class WeeklyClass(models.Model):
status = models.CharField(
max_length=1,
choices=STATUS_CHOICES,
default="A")
students = models.ManyToManyField(
Profile,
limit_choices_to=models.Q(is_teacher=False),
related_name='student_weekly_classes',)
teachers = models.ManyToManyField(
Profile,
limit_choices_to=models.Q(is_teacher=True),
related_name='teacher_weekly_classes',)
class Meta:
verbose_name = 'Class'
verbose_name_plural = 'Classes'
ordering = ["-created"]
forms.py
class WeeklyClassForm(ModelForm):
class Meta:
model = WeeklyClass
fields = [
"status",
"students",
"teachers",
"weekday",
"duration_hours",
"hour",
"minute"]
views.py
#login_required
def new_weekly_class(request):
if request.method == "POST":
form = WeeklyClassForm(request.POST)
if form.is_valid():
form.save()
return redirect(reverse(
"weekly_class_list",
kwargs={"username": request.user.username}))
else:
form = WeeklyClassForm()
return render(
request,
"weekly_classes/new_weekly_class.html",
{"form": form})

Answer 1

form.save() does not directly save the many to many instances so after saving the form.save() also call form.save_m2m() to save manytomay relationship.
#login_required
def new_weekly_class(request):
if request.method == "POST":
form = WeeklyClassForm(request.POST, request.FILES)
if form.is_valid():
form.save()
form.save_m2m()
return redirect("weekly_class_list", kwargs={"username": request.user.username})
else:
form = WeeklyClassForm()
template = "weekly_classes/new_weekly_class.html"
context = {"form": form}
return render(request, template, context)
for reference: https://docs.djangoproject.com/en/dev/topics/forms/modelforms/#the-save-method