I'm having some issues with django forms. This is the error I'm getting:
ValueError at /coach/new/
Cannot assign "u'7'": "Course.category" must be a "Category" instance.
views.py
def create_course_page(request):
if request.method == 'POST': # If the form has been submitted...
form = CreateCourseForm(request.POST) # A form bound to the POST data
#form.data['category'] = Category.objects.get(pk=form.data['category']),
if form.is_valid(): # All validation rules pass
cleaned_data = form.cleaned_data
my_course = Course(
title = cleaned_data['title'],
prerequisite = cleaned_data['prerequisite'],
category = Category.objects.get(pk=cleaned_data['category']),
short_description = cleaned_data['short_description'],
#listing_city = cleaned_data['xxxx'],
date_created = datetime.now(),
date_last_updated = datetime.now(),
teacher = request.user,
)
my_course.save()
return HttpResponseRedirect('/') # Redirect after POST
else:
return HttpResponseRedirect('/wtf') # Redirect after POST
else:
my_course = Course()
form = CreateCourseForm(instance=my_course) # An unbound form
return render(request, 'learn/new_course.html', {
'form': form,
})
I tried to fix the problem with "form.data['category'] = Category.objects.get(pk=form.data['category']),", but that's not going to do it.
Does anyone have a better idea? Thanks a lot.
EDIT: Traceback shows that the error happens at
if form.is_valid(): # All validation rules pass
EDIT2: This might explain better, why django forms doesn't work with the "default" programming:
forms.py
def categories_as_choices():
categories = [(u'', u'')] # So select box get's an empty value/default label
for category in Category.objects.all():
new_category = []
sub_categories = []
for sub_category in category.get_children():
sub_categories.append([sub_category.id, sub_category.name])
new_category = [category.name, sub_categories]
categories.append(new_category)
return categories
class CreateCourseForm(ModelForm):
category = forms.ChoiceField(choices=categories_as_choices()) #chzn-select
class Meta:
model = Course
fields = ('title', 'category')
def __init__(self, *args, **kwargs):
super (CreateCourseForm, self).__init__(*args, **kwargs)
self.fields['category'].widget.attrs['class'] = 'chzn-select'
try this
get_cat_name = form.cleaned_data['category']
get_obj = Category.objects.get(category = get_cat_name)
category = get_obj.id
category = Category.objects.get(pk=cleaned_data['category'])
Normally you do not need related Category
object, just giving the cleaned_data
is enough and the right way to go.
my_course = Course(......, category = cleaned_data['category'], ...)
Or if you have to work with related category id, then each ForeignKey
model field can be used as <field_name>_id
. But you must give a valid foreignkey, not the related object.
my_course = Course(......, category_id = 8, ...)
You can try
my_course = Course(..., category = form.cleaned_data['category']), ...)
The form.cleaned_data
would have category instance.
However, much recommended way is to just save the form as
my_course = form.save()
If you want to manually change some fields, do
my_course = form.save(commit=False)
my_course.some_field = some_value
...
my_couse.save()
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