I'm new to Django and I have built a Form that shows a single select field to chose from. The data in the field are calculated on the go by the Form.
I now need, once the data is being submitted, to be save on the database. The only problem is that, for some reason, I got an IntegrityError error NOT NULL constraint failed: manager_playlist.user_id
Below my view, form and model in Django
views.py
def playlist(request):
if not is_user_already_auth_spotify(request):
messages.error(request, "You're not authenticated with Spotify, please authenticate here")
return redirect('/members/account/' + request.user.username)
if request.method == "POST":
form = ChoosePlaylistForm(request.POST, request=request)
if form.is_valid():
form.save()
messages.success(request, "Playlist successfully chosen")
return HttpResponseRedirect('account')
else:
pass
else:
form = ChoosePlaylistForm(request=request)
return render(request, 'show_playlist.html', {"playlist_choose_form": form})
forms.py
class ChoosePlaylistForm(ModelForm):
playlists = forms.ChoiceField(choices=())
class Meta:
model = Playlist
fields = ('playlists',)
def __init__(self, *args, request=None, **kwargs):
super(ChoosePlaylistForm, self).__init__(*args, **kwargs)
self.request = request
self.fields['playlists'].choices = self.generate_selection()
def generate_selection(self):
sp_auth, cache_handler = spotify_oauth2(self.request)
spotify = spotipy.Spotify(oauth_manager=sp_auth)
s_user = spotify.current_user()
u_playlists = spotify.user_playlists(s_user['id'], limit=10)
choices = []
for playlist in u_playlists["items"]:
if playlist["owner"]["id"] == s_user['id']:
playlist_choice = (playlist["id"], playlist["name"])
choices.append(playlist_choice)
else:
pass
return choices
model.py
class Playlist(models.Model):
user = models.OneToOneField(User, on_delete=models.CASCADE)
playlists = models.CharField(max_length=50, null=True, blank=True) # playlists are the ids of the playlists
def __str__(self):
return self.playlists
The reason for the error is that when a new Playlist object is created, the user field must not be empty (you did not add null=True, and of course, would not make sense here if you did). Now the form validates because the form does not require the user field, only the playlists field. You have a couple of choices.
Option 1
Add the required field to your form (I haven't tested this, please check the docs!):
class ChoosePlaylistForm(ModelForm):
playlists = forms.ChoiceField(choices=())
class Meta:
model = Playlist
fields = ('playlists', 'user',) # NOTE THE CHANGE HERE
def __init__(self, *args, request=None, **kwargs):
super(ChoosePlaylistForm, self).__init__(*args, **kwargs)
self.request = request
self.user = request.user # Add the user to the form
Option 2
Save the form as is using commit=False, then add the missing field before you save your model:
if request.method == "POST":
form = ChoosePlaylistForm(request.POST, request=request)
if form.is_valid():
playlist = form.save(commit=False) # NOTE THE CHANGE HERE
playlist.user = request.user # Add the user to the partial playlist
playlist.save() # Now you can save the playlist
messages.success(request, "Playlist successfully chosen")
return HttpResponseRedirect('account')
Option 3
Add the field when you instantiate the form itself (I'm not sure my syntax is correct here):
form = ChoosePlaylistForm(request.POST, request=request, instance=request.user)
EDIT
Option 3 above does not seem to work. I believe this edit will:
form = ChoosePlaylistForm(request.POST, request=request, initial={'user': request.user})
Related
I have the following model in Django which I use to store data about medicines.
class Medicine(models.Model):
Medicine_Name = models.CharField(max_length=100)
User_Associated = models.ForeignKey(User, on_delete=models.CASCADE)
Tablets_In_Box = models.IntegerField()
Dose_in_mg = models.IntegerField()
Dose_Tablets = models.IntegerField()
Number_Of_Boxes = models.IntegerField()
Last_Collected = models.DateField()
def __str__(self):
return self.Medicine_Name
def get_absolute_url(self):
return reverse('tracker-home')
I am trying to create a model form where a user can update the last collection of one of their medicines. Here is what I began with.
class CollectionForm(forms.ModelForm):
class Meta:
model = Medicine
fields = ['Medicine_Name', 'Number_Of_Boxes', 'Last_Collected']
I do not understand how I can call an instance of my model based on the 'Medicine_Name' from the field. In other words, I need the user to be able to select the correct medicine from a dropdown menu, and then the form must update the 'Last_Collected', and 'Numer_Of_Boxes' fields on my Medicine model.
https://docs.djangoproject.com/en/2.1/topics/forms/modelforms/#the-save-method
It seems this contains relevant information, but I struggle to see how to use it in this instance. How can I correctly get the instance of the medicine form I need, based on the user input in the form? Furthermore how can I use the save method in my views to make sure the database gets updated correctly?
EDIT Added view for the form:
def update(request, pk):
instance = Medicine.objects.get(id=pk)
if request.method == 'POST':
form = CollectionForm(user=request.user, instance=instance, data=request.POST)
if form.is_valid():
instance = form.save(commit=False)
instance.User_Associated = request.user
instance.save()
else:
form = CollectionForm()
context = {'form': form}
return render(request, 'tracker/medicine_collection.html', context )
**EDIT
views:
def update(request, pk):
instance = Medicine.objects.get(id=pk)
if request.method == 'POST':
form = CollectionForm(instance=instance, data=request.POST)
if form.is_valid():
instance = form.save(commit=False)
instance.User_Associated = request.user
instance.save()
return redirect ('/')
....
This is based on updating the instance of the specific user. This tutorial helpt me achieve the same thing.
https://youtu.be/EX6Tt-ZW0so
Tried a different approach (class based views - UpdateView) I just learned here on SO. Did not test it but I think its a step in the right direction.
class UpdateMedicine(LoginRequiredMixin, UpdateView):
model = Medicine #call the model you need to update
fields = ['Medicine_Name', 'Number_Of_Boxes', 'Last_Collected'] #specify the fields you need to update
template_name_suffix = 'medicine_update_form' #specify the template where the update form is living
def get_context_data(self, **kwargs):
context = super().get_context_data(**kwargs)
context.update(
user=self.request.user, #get the current logged in user
instance=get_object_or_404(Medicine, pk=self.kwargs['pk']) #get the pk of the instance
)
return context
def form_valid(self, form):
form.instance.medicine = get_object_or_404(Medicine, slug=self.kwargs['pk'])
return super().form_valid(form) #saves the updates to the instance
def get_success_url(self):
return reverse('medicine-collection') #name of the url where your 'tracker/medicine_collection.html is living
Link the appropriate templates and urls to the above example and try some things yourself.
Link to the django docs:
https://docs.djangoproject.com/en/3.0/ref/class-based-views/generic-editing/
Good luck!
I am trying to create a form that allows current logged in user to submit data.
The form comprises of the field - amount, rate(interest), timestamp(automatically picked up), and currently logged in user.
Data is not passing into the database and giving an error like - The view investors.views.InvestView didn't return an HttpResponse object. It returned None instead.
views.py
def InvestView(request):
if request.method == 'GET':
investment_form = InvestorsForm(request.user)
context = {'investment_form': investment_form}
return render(request, 'investors/form.html', context)
if request.method == 'POST':
investment_form = InvestorsForm(request.POST or None, instance=request.user)
if investment_form.is_valid():
amount = investment_form.cleaned_data['amount']
interest = investment_form.cleaned_data['rate']
saving = investment_form.save(commit=False)
# Passing Logged in user
investor = request.user
print(investor)
saving.investor = request.user.id
saving.save()
messages.success(request, f'New Investment Done!')
return redirect('/myinvest/')
forms.py
class InvestorsForm(forms.ModelForm):
class Meta :
model = Investment
fields = ['amount', 'rate']
def __init__(self, user, *args, **kwargs):
self.user = user
super(InvestorsForm, self).__init__(*args, **kwargs)
models.py
class Investor(models.Model):
name = models.CharField(max_length=99)
user = models.ForeignKey(User, on_delete=models.CASCADE)
def __str__(self):
return self.name
class Investment(models.Model):
amount = models.FloatField(blank=False)
rate = models.FloatField(blank=False)
timestamp = models.DateField(default=datetime.now)
investor = models.ForeignKey(Investor, on_delete=models.CASCADE)
def __str__(self):
return str(self.investor)
Data must be stored into the database and redirect the page to myinvest section simultaneously.
This issue has nothing to do with adding the user. It is because you do nothing in case the validation fails.
You should turn your function the other way round so that the render is hit in all cases.
def InvestView(request):
if request.method == 'POST':
investment_form = InvestorsForm(request.POST)
if investment_form.is_valid():
saving = investment_form.save(commit=False)
saving.investor.user = request.user
saving.save()
messages.success(request, f'New Investment Done!')
return redirect('/myinvest/')
else:
investment_form = InvestorsForm()
context = {'investment_form': investment_form}
return render(request, 'investors/form.html', context)
Note the indentation.
The actual failure to validate is because you have changed the signature of the form to accept a user parameter first, instead of the expected data. However it is not clear why you have done this as you do not use that value, but instead set the user in the view. You should remove that __init__ method.
Another error: your form's __init__ method takes a user as its first argument:
def __init__(self, user, *args, **kwargs):
In the case of a GET request, you pass it correctly:
investment_form = InvestorsForm(request.user)
But then with a POST request, you forget it:
investment_form = InvestorsForm(request.POST or None, instance=request.user)
Passing request.user as the first argument there as well should help.
You need to replace saving.investor = request.user.id with saving.investor.user = request.user.
model
class Person(models.Model):
first_name = models.CharField(blank=False,max_length=256,default='')
last_name = models.CharField(blank=False,max_length=256,default='')
plan = models.CharField(blank=False,max_length=256,default='')
plan_price = models.CharField(blank=False,max_length=256,default='')
Views.py
if request.method == 'POST':
if form.is_valid():
form.save(commit=True)
return index(request)
In my modelForm I accept 3 values from the user: first_name, last_name, and plan. I dont have any problem with posting to the database from the form, what i am trying to find out is how I can say something like this
if plan = 'plan1':
#set plan_price to '$399'
else
#set plan_price to '$699'
#then post first_name, last_name, plan, plan_price to database
You can try the following:
if form.is_valid():
person = form.save(commit=False)
plans = {
'plan1': 399,
'plan2': 699,
# ...
}
person.plan_price = plans.get(person.plan, some_default)
person.save()
return index(request)
# you might consider a redirect instead so as not to have the same content on various urls
If the plan price always should match the plan you can also override the model's save method and leave the view as you had it:
class Person(models.Model):
# ...
def save(self, *args, **kwargs):
self.plan_price = some_logic(self.plan)
super(Person, self).save(*args, **kwargs)
But then, you could replace that field by a property alltogether as it seems redundant. If plans, for instance, change prices, I would consider a Plan model with a name and price field.
in your createview you can use this function and write your code there
def form_valid(self, form):
if self.object.plan = 'plan1':
form.instance.price = 399
else:
[...]
return super(your_class_name, self).form_valid(form)
you can access the created object fields by self.object.filed
I am trying to create a dynamic choice field. I have a view that creates a list of tuples. The first value of the tuple is the primary key of the object ServiceWriter while the second value is the name of the ServiceWriter. The list then gets passed into the form class. When I make the selection and submit the page the form is decided to be not valid and the following form error is printed in the shell: "Select a valid choice. (First value of tuple. ie 1,2,3..) is not one of the available choices."
forms.py
class CreateAdvancedRO(forms.Form):
service_writer = forms.ChoiceField()
def __init__(self, writer_choices, *args, **kwargs):
super(CreateAdvancedRO, self).__init__(*args, **kwargs)
self.fields['service_writer'].choices = writer_choices
self.helper = FormHelper()
self.helper.form_id = 'id-create-advanced-ro'
self.helper.form_method = 'post'
self.helper.add_input(Submit('submit', 'Open Repair Order'))
Note: I am not using a ModelForm.
views.py
class CreateAdvancedRO(View):
form_class = CreateAdvancedRO
writer_form = CreateServiceWriter
add_line_form = AddJobLine
def post(self, request):
writer_choices = []
form = self.form_class(writer_choices, request.POST)
print(form.errors)
if form.is_valid():
'''Do something'''
else:
writer_choices = []
try:
writers = ServiceWriter.objects.filter(user=request.user)
for writer in writers:
writer_choices.append((str(writer.id), writer.name))
except ObjectDoesNotExist:
pass
form = self.form_class(writer_choices, request.POST)
writer_form = self.writer_form()
add_line_form = self.add_line_form()
return render(request, 'free/advanced_create.html', {'form': form, 'writer_form': wri
'add_line_form': add_line_form})
I have tried both of the following in the view:
writer_choices.append((str(writer.id), writer.name)) and
writer_choices.append((writer.id, writer.name))
Here is the ServiceWriter model, just in case.
class ServiceWriter(models.Model):
user = models.ForeignKey(User)
name = models.CharField(max_length=20, blank=False)
def __str__(self):
return str(self.name)
Any thoughts?
Thanks for the help.
It looks like you're trying to validate the form against an empty list of choices. Have you tried populating writer_choices before instantiating or attempting to validate the form?
I have created a model Student which extends from the Django User and is a foreign key to another model while it has an integer field called year. What i'm trying to do is to save a form, which has 2 fields. The one is the course id and the another one is the the integer field year. When I'm clicking submit, i'm getting an error Cannot assign "u'2'": "Student.course" must be a "Course" instance.
models.py
class Student(models.Model):
user = models.OneToOneField(User)
course = models.ForeignKey(Course)
year = models.IntegerField(validators=[MinValueValidator(1),
MaxValueValidator(7)])
view.py
def step3(request):
user = request.user
if request.method == 'POST':
form = SelectCourseYear(request.POST)
if form.is_valid():
form.save()
return render_to_response("registration/complete.html", RequestContext(request))
else:
form = SelectCourseYear()
return render(request, 'registration/step3.html',)
forms.py
class SelectCourseYear(forms.ModelForm):
course = forms.CharField()
year = forms.IntegerField(required=True)
class Meta:
model = Student
fields = ['user', 'course', 'year']
You dont need to redefine fields in the ModelForm if you've already mentioned them in the fields attribute. So your form should look like this -
class SelectCourseYear(forms.ModelForm):
class Meta:
model = Student
fields = ['course', 'year'] # removing user. we'll handle that in view
And we can handle the form with ease in the view -
def step3(request):
user = request.user
if request.method == 'POST':
form = SelectCourseYear(request.POST)
if form.is_valid():
student = form.save(commit=False)
# commit=False tells Django that "Don't send this to database yet.
# I have more things I want to do with it."
student.user = request.user # Set the user object here
student.save() # Now you can send it to DB
return render_to_response("registration/complete.html", RequestContext(request))
else:
form = SelectCourseYear()
return render(request, 'registration/step3.html',)
course has to be an instance of a Course model, not just the primary key of the instance. You can still accept an id in the form as a text input, but you're going to need to retrieve the actual course instance and assign the value.
You'll need to verify that the course id is valid, so putting that code into the clean method isn't a bad idea. Notice also how the course field is excluded here? Otherwise the form will expect it to be present. You also don't need to re-define the year field, as the ModelForm will inherit that field from the Student model.
# forms.py
class SelectCourseYear(forms.ModelForm):
class Meta:
model = Student
exclude = ['user', 'course']
course_id = forms.IntegerField()
def __init__(self, *args, **kwargs):
self.user = kwargs.pop('user')
super(SelectCourseYear, self).__init__(*args, **kwargs)
def clean_course_id(self):
course_id = self.cleaned_data.get('course_id')
try:
self.course = Course.objects.get(pk=course_id)
except Course.DoesNotExist:
raise forms.ValidationError('Sorry, that course id is not valid.')
return course_id
def save(self, commit=True):
instance = super(SelectCourseYear, self).save(commit=False)
instance.course = self.course
instance.user = self.user
if commit:
instance.save()
return instance
# views.py
def step3(request):
if request.method == 'POST':
form = SelectCourseYear(request.POST or None, user=request.user)
if form.is_valid():
form.save()
return render_to_response("registration/complete.html",
RequestContext(request))
return render(request, 'registration/step3.html',)
Now, when you call .save() on the model, the course field will be assigned an instance of Course