I have created the following models. Many Accounts belong to one Computer.
class Computer(models.Model):
name = models.CharField(max_length=256)
def __str__(self):
return str(self.name)
class Accounts(models.Model):
computer = models.ForeignKey(Computer, on_delete=models.CASCADE, related_name='related_name_accounts')
username = models.CharField(max_length=10)
def __str__(self):
return str(self.username)
I now want to create a Form where i can choose one user from a dropdown-list of all users that belong to a Computer
class ComputerForm(forms.ModelForm):
class Meta:
model = Computer
exclude = ['name',]
def __init__(self, *args, **kwargs):
super(ComputerForm, self).__init__(*args, **kwargs)
self.fields['user']=forms.ModelChoiceField(queryset=Computer.related_name_accounts.all())
But i get an error
'ReverseManyToOneDescriptor' object has no attribute 'all'
How do i have to adjust the queryset in __init__ to display all users of a computer?
Edit:
>>> x = Computer.objects.filter(pk=3).get()
>>> x.related_name_accounts.all()
I would somehow need to pass the dynamic pk to the ModelForm?
Your issue is that you used a capital C in Computer.related_name_accounts.all(). This doesn't make sense, because the Computer model doesn't have related fields - it's instances do.
This line of code would work:
computer = Computer.objects.get(id=1)
computer.related_name_accounts.all()
But the issue is, I am not sure what you mean by ...of all users that belong to a Computer, since you don't have a ForeignKey or OneToOne relationship between User and Computer.
You can pass an instance of your model to the form like this:
x = Computer.objects.get(pk=3)
form = ComputerForm(instace=x)
And access it through self.instance in the form methods:
class ComputerForm(forms.ModelForm):
class Meta:
model = Computer
exclude = ['name',]
def __init__(self, *args, **kwargs):
super(ComputerForm, self).__init__(*args, **kwargs)
self.fields['user']=forms.ModelChoiceField(
queryset=self.instance.related_name_accounts.all()
)
Related
I have been trying for awhile now without any luck.. I have model Like this:
class List(models.Model):
name = models.CharField(max_length=100, default="")
user = models.ForeignKey(User, on_delete=models.CASCADE, related_name='lists')
def __str__(self):
returnself.name
class Meta:
unique_together = ['name', 'user']
Every user can create their own lists and add values to those lists. I have adding values and everything else working but to the form that adds these values I would somehow need to filter to show only users own lists, now its showing all lists created by every user... this is the form:
class data_form(forms.Form):
user_lists = List.objects.all()
selection = forms.ModelChoiceField(queryset=user_lists)
data = forms.IntegerField()
Any ideas how to filter it? I have tempoary "list.objects.all()" since dont want it to give error that crashes the server. I have watched a ton of examples on stackoverflow but none of them seems to be exact thing that I am looking for.. Thanks already for asnwers! :)
You need to get hold of the current user, e.g. like so or so.
That is, you pass request.user to the form when instantiating it in your view:
frm = DataForm(user=request.user)
In the __init__ of your form class, you can then assign the user-filtered queryset to your field:
class DataForm(forms.Form):
def __init__(self, *args, **kwargs):
user = kwargs.pop("user")
super(DataForm, self).__init__(*args, **kwargs)
self.fields['selection'].queryset = List.objects.filter(user=user)
You can set your form to take the user when initialized, and from there get a new queryset filtered by user.
class DataForm(forms.Form):
selection = forms.ModelChoiceField(queryset=List.objects.none())
data = forms.IntegerField()
def __init__(self, user, *args, **kwargs):
super().__init__(*args, **kwargs)
self.fields['selection'].queryset = List.objects.filter(user=user)
You would inititialize the form like this:
form = DataForm(request.user)
I am wondering if it's possible to auto create a related model upon creation of the first model.
This is the models
class Team(models.Model):
name = models.CharField(max_length=55)
class TeamMember(models.Model):
team = models.ForeignKey('Team', on_delete=models.CASCADE, null=False)
user = models.ForeignKey(settings.AUTH_USER_MODEL, on_delete=models.CASCADE, null=False)
So what I want to do is something like this on the 'Team' model
class Team(models.Model):
name = models.CharField(max_length=55)
#on_new.do_this
TeamMember.team = self
TeamMember.user = request.user
TeamMember.save()
I have tried to find any documentation about this. But only found some example about onetoonefields. But nothing about this.
Appreciate any help. Cheers!
I am assuming you are using forms to create team.
There is no direct way to create the TeamMember instance without the current user(via request). request is available in views only(unless you are using special middleware or third party library to access it), so we can send it form and create the user by overriding the save method of the modelform.
So you can try like this:
# Override the model form's save method to create related object
class TeamForm(forms.ModelForm):
def __init__(self, *args, **kwargs):
self.request = kwargs.pop('request', None)
super(TeamForm, self).__init__(*args, **kwargs)
class Meta:
model = Team
def save(self, **kwargs):
user = self.request.user
instance = super(TeamForm, self).save(**kwargs)
TeamUser.objects.create(team=instance, user=user)
return instance
And use this form in View:
# Update get_form_kwargs methods in create view
class TeamCreateView(CreateView):
form_class = TeamForm
template = 'your_template.html'
def get_form_kwargs(self):
kw = super(TeamCreateView, self).get_form_kwargs()
kw['request'] = self.request
return kw
Update
(from comments)If you have the user FK availble in Team then you can use it to create TeamMember by overriding the save method. Try like this:
class Team(models.Model):
user = models.ForeignKey(User, on_delete=models.SET_NULL)
name = models.CharField(max_length=55)
def save(self, *args, **kwargs): # <-- Override
instance = super(Team, self).save(*args, **kwargs)
TeamMember.objects.create(user=instance.user, team=instance)
return instance
I've surfed most of the afternoon and have been at this particular quandry for a while.
I am trying to figure out how to essentially present a foreign key as a dropdown choice if the user has driven that type of car. For example purposes and to keep this as easy as possible...
Let's say I have aCars, Manufacturers and a UserProfile model.
I have a model for Cars as so...
class Cars(models.Model):
car_name = models.CharField(max_length=80)
class = models.ForeignKey(Manufacturer,null=True,on_delete=models.DO_NOTHING,related_name='car_manufacturer')
I have a model for Manufacturers as so...
class Manufacturers(models.Model):
manu_name = models.CharField(max_length=80)
Then I have a UserProfile model....
class Userprofile(models.Model):
user = models.OneToOneField(User,on_delete=models.CASCADE)
user_name = models.CharField(max_length=80)
car_owned = models.ForeignKey(Car,null=True,on_delete=models.DO_NOTHING,related_name='car_owned')
All good so far...
I have a view where I am listing all of the Manufacturers and this works fine as well. It shows all of the manufacturers that I would expect in the form view below.
class ManufacturerForm(forms.Form):
dropdown = forms.ModelChoiceField(queryset=Manufacturer.objects.all())
def __init__(self, *args, **kwargs):
super(ManufacturerForm, self).__init__(*args, **kwargs)
self.fields['dropdown'].widget.attrs['class'] = 'choices1'
self.fields['dropdown'].empty_label = ''
I'm using the FORMVIEW below to display the form...
class ManufacturerView(LoginRequiredMixin,FormView):
form_class = ManufacturerForm
template_name = 'Directory/HTMLNAME.html'
def get_form_kwargs(self):
kwargs = super(ManufacturerView, self).get_form_kwargs()
kwargs['user'] = self.request.user
return kwargs
def form_valid(self, form):
manufacturer = form.cleaned_data['dropdown']
return HttpResponseRedirect(reverse("NAME:manufacturer",kwargs={'pk':manufacturer.pk}))
This all works fine. However, I can't figure out how to limit the manufacturer dropdown to only the cars the user has driven. I'm trying to essentially limit the dropdown display to only the manufacturers that are pertinent to the cars the user has owned based on their profile. I've researched reverse look ups and have also tried something similar to what is outlined below to solve my problem...
class ManufacturerForm(forms.Form):
dropdown = forms.ModelChoiceField(queryset=Manufacturer.objects.filter(car_manufacturer=1)
def __init__(self, *args, **kwargs):
super(ManufacturerForm, self).__init__(*args, **kwargs)
self.fields['dropdown'].widget.attrs['class'] = 'choices1'
self.fields['dropdown'].empty_label = ''
But this obviously only gives me record 1 for the Manufacturer model. I am trying to figure out how to display only the records that are relevant to an individual user based on their car_owned data. I can list all of the manufacturers and then just display the records that are relevant in a ListView, but I am trying to limit the dropdown to only where there are relevant records in a ListView. Thanks in advance for any thoughts.
You missed just couple of points:
1) Pass UserProfile as kwargs['user']:
kwargs['user'] = UserProfile.objects.get(user=self.request.user)
2) Add user parameter in form's __init__ signature and override dropdown.queryset there:
class ManufacturerForm(forms.Form):
dropdown = forms.ModelChoiceField(queryset=Manufacturer.objects.all())
def __init__(self, user, *args, **kwargs):
super(ManufacturerForm, self).__init__(*args, **kwargs)
self.fields['dropdown'].widget.attrs['class'] = 'choices1'
self.fields['dropdown'].empty_label = ''
self.fields['dropdown'].queryset = Manufacturer.objects.filter(car_manufacturer__car_owned=user)
Also I would like to recommend to rewrite your Car - User relationship to ManyToMany. If I understand correctly your message, User can have multiple cars:
limit the dropdown display to only the manufacturers that are
pertinent to the cars the user has owned
Also if I understand correctly, you want to track cars that user used to have (but doesn't have anymore).
If you rewrite Car - User relationship, then you won't probably have any reason to keep UserProfile model only to hold additional username. If so, your models.py should look like this:
class Manufacturer(models.Model):
name = models.CharField(max_length=80)
class Car(models.Model):
name = models.CharField(max_length=80)
klass = models.ForeignKey(Manufacturer, null=True, on_delete=models.DO_NOTHING, related_name='car_manufacturer')
owners = models.ManyToManyField(User, through='Ownership')
class Ownership(models.Model):
user = models.ForeignKey(User, on_delete=models.CASCADE)
car = models.ForeignKey(Car, on_delete=models.CASCADE)
active = models.BooleanField(default=True) # True if user owns the car at the moment
I think it all hinges on your order and relationships between models, perhaps try adding in a ManyToMany relation between Manufacturer and Car, so one manufacturer can make many cars:
class Manufacturer(models.Model):
name = models.CharField(max_length=80)
car = models.ManyToManyField(Car)
Then it may be a case of doing something such as:
qs = Manufacturer.objects.all(car=user.car_owned)
dropdown = forms.ModelChoiceField(qs)
And in your views.py file:
form = ManufacturerForm(request.POST, user=request.user)
(You may need to look up if the above is valid, as I'm not sure if Forms can have the request object passed in).
Disclaimer: I see you're using a class based view...so I may need to tweak the above.
I have a data model where I am using a manual intermediate table for a m2m relationship.
Building on the classical example from the django doc:
from django.db import models
INSTRUMENT_CHOICES = (
('guitar', 'Guitar'),
('bass', 'Bass Guitar'),
('drum', 'Drum'),
('keyboard', 'Keyboard'),
)
class Person(models.Model):
name = models.CharField(max_length=128)
def __str__(self):
return self.name
class Group(models.Model):
name = models.CharField(max_length=128)
members = models.ManyToManyField(Person, through='Leadership')
def __str__(self):
return self.name
def get_leadership():
return self.leadership_set.first()
class Leadership(models.Model):
person = models.ForeignKey(Person, on_delete=models.CASCADE)
group = models.ForeignKey(Group, on_delete=models.CASCADE)
instrument = models.CharField('Playing Instrument', choices=INSTRUMENT_CHOICES,
max_length=15,
null=True,
blank=False)
class Meta:
unique_together = ('person', 'group')
When I create a new group I also want to specify who is going to be the leader, and for this relationship also specify which instrument he will play in that group.
What really confuses me, given also the lack of documentation on this topic is how to handle this kind of relationship in forms.
This is the form I came with:
class InstrumentField(forms.ChoiceField):
def __init__(self, *args, **kwargs):
super().__init__(INSTRUMENT_CHOICES, *args, **kwargs)
class GroupForm(forms.ModelForm):
instrument = InstrumentField(required=False)
class Meta:
model = Group
fields = ['name',
'members'
'instrument'] # This works but it's not correctly initalized in case of edit form
def __init__(self, *args, **kwargs):
super().__init__(*args, **kwargs)
if self.instance.pk is not None: # editing
# PROBLEM: this doesn't work
self.fields["instrument"].initial = self.instance.get_leadership().instrument
def save(self, commit=True):
group = super().save(commit=False)
if commit:
group.save()
if 'instrument' in self.changed_data:
leader = self.cleaned_data.get('members').first()
instrument = self.cleaned_data['instrument']
Leadership.objects.update_or_create(person=leader, group=group, defaults={'instrument': instrument})
return group
As suggested in the django doc I am manually instantiating Leadership objects (see the form save method).
What I couldn't solve is how to populate the instrument field in case of form editing. I try to do this in the __init__: first I check that we are in "edit" mode (the instance has a pk) then I get the relevant Leadership object (see Group.get_leadership) and from that I extract the instrument and I assign it to the fields["instrument"].initial.
This doesn't work.
I could inspect that the initial value was set but then when I render the form the default choice value is shown (the first value of the INSTRUMENT_CHOICES).
What am I missing here?
Is there a better way or a better docs on how to handle m2m with through model in forms?
I have two models in my project. Model A and B. Model B has a 'OneToOne' relationship with model A. I wrote a serializer class for model B. in ".create()" function I have a problem with saving model B, because I need to override the save() function in B model for inserting Slug value. The error is:
save() got an unexpected keyword argument 'force_insert'
class A(models.Model):
address = models.Charfield(max_length=160)
class b(models.Model):
a = models.OneToOneField(AdIfo, related_name='ad_info', primary_key=True,
on_delete=models.CASCADE)
slug = models.SlugField(unique=True, db_index=True, blank=True)
def save(self):
self.slug ="%d%s" %(self.pk, slugify(self.title))
super(B, self).save()
serializers.py
class ASerializer(serializers.ModelSerializer):
class Meta:
model = A
fields = "__all__"
class BSerilizer(serializers.ModelSerializer):
a = ASerializer(many=False, required=False, allow_null=True)
slug = serializers.SlugField(read_only=True)
class Meta:
model = B
fields = '__all__'
def create(self, validated_data):
info_data = validated_data.pop('ad_info')
A.objects.create(**info_data)
ad = B.objects.update_or_create(**validated_data)
A.objects.update_or_create(ad_info=adgame, **info_data)
ad.save()
return ad
The problem is that you didn't accept the default arguments in B's save method. Generally when overriding a method you need to ensure you accept all the arguments that could be passed, and make sure you pass them on to the super class method. One way of doing that is with *args, **kwargs:
def save(self, *args, **kwargs):
self.slug ="%d%s" % (self.pk, slugify(self.title))
super(B, self).save(*args, **kwargs)
well your problem is you are trying to make model A and model B then.the model B depends on primary key of model A .this structure you made is making model A and there is no relating on model B and then you are creating model A again.
you just need to create model A and then model B but you should refer the model B id to model A. i know its confusing but try this :
def create(self, validated_data):
info_data = validated_data.pop('ad_info')
info = A.objects.create(**info_data)
ad = B.objects.create(pk=info.id, **validated_data)
return ad
pk=info.id is the key for this problem.
After you done the fix by #Daniel Roseman t think you should updated your validated_data with new instance of the A instance
def create(self, validated_data):
info_data = validated_data.pop('ad_info')
# Next two rows
a = A.objects.create(**info_data)
validated_data.update({'a': a})
ad = B.objects.update_or_create(**validated_data)
A.objects.update_or_create(ad_info=adgame, **info_data)
ad.save()
return ad