I study the CBV in django.
I want a user can upload images to a certain card of an apartment.
So The model was created:
class Photo(models.Model):
photo_path = models.ImageField(verbose_name='Фотография')
photo_user = models.ForeignKey(User, verbose_name='Агент, добавивший фото')
photo_flat = models.ForeignKey(Flat, verbose_name='Квартира')
photo_description = models.CharField(verbose_name='Описание', max_length=200, null=True, blank=True)
The initial data of the form are photo_user and the photo_flat.
When I try to save one or multiple pictures through a form on the page I've got AttributeError.
'NoneType' object has no attribute 'pk'
My ModelForm looks like this:
class PhotoUploadModelForm(forms.ModelForm):
class Meta:
model = Photo
fields = ['photo_path','photo_user','photo_flat','photo_description'
My CreateView:
class PhotoUploadView(CreateView):
form_class = PhotoUploadModelForm
def get_initial(self):
return {'photo_user': self.request.user,
'photo_flat': self.object.pk
}
def get_success_url(self):
return reverse('ha:flatdetail')
and my urls.py
url(r'^dev/flat/(?P<flat_id>[0-9]+)/$', views_dev.flat_ajax, name='flatdetail'),
url(r'^dev/photo-update/$', views_dev.PhotoUploadView.as_view(), name='image-update')
I understand the error but has not enough skills to handle it. am I correct that self.object.pk would be the id of the picture but not the apartment?
Can I get the id of the apartment?
You're misinterpreting the error, but that is partly because what you're doing doesn't make a lot of sense.
self.object can only refer to the object that this view is concerned with, which in this case is the Photo; but of course that photo doesn't exist yet when you do get_initial, because it hasn't been created. It seems that you want to use the ID of a specific Flat object; in which case you would need to pass that ID to the view, ie via the URL. You do this already in your flat_ajax view; you should do exactly the same thing here, and then you will be able to reference the ID via self.kwargs['flat_id'].
Note that get_initial isn't really the best place to be doing this, anyway. The User and the Flat object are not values that you want to pass to the form so that they populate fields initially but let the user change them; they are values you want to automatically associate with the object on save. So, this should really be done in form_valid, as shown in the documentation:
def form_valid(self, form):
form.instance.photo_user = self.request.user
form.instance.photo_flat_id = self.kwargs['flat_id']
return super(PhotoUploadView, self).form_valid(form)
If you do it this way, you should remove photo_user and photo_flat from the fields listed in the form.
Related
I'm currently trying to build an application in Django where users should be able to create new entries for a model. Said model contains a ForeignKey relation to a different model. However, the classic dropdown form field is not practical, because there could be hundreds of entries to choose from. Instead, I'd like to allow users to simply type in the name of the entry (all names are unique), which then gets transformed to the corresponding ID when pressing the Submit button.
I feel like this should be pretty straightforward to do, but since I'm new to Django I'm having a hard time to figure out how to do it. Currently the problem is, that the form field is declared invalid, due to the ForeignKey not existing (since the user typed in the name and not the ID of the database entry).
Code example:
forms.py:
class DogForm(ModelForm):
class Meta:
model = Dog
fields = "__all__"
widgets = {" shelter": widgets.TextInput(attrs={"id":" shelter", "placeholder":" Dog Shelter"}),
"name": widgets.TextInput({"id":"name", "placeholder":"Name"}),
def clean(self):
shelter= self.data.get("shelter")
self.cleaned_data["shelter"] = Shelter.objects.get(name=shelter)
return self.cleaned_data
views.py:
class DogCreate(CreateView):
model = Dog
form_class = DogForm
def form_valid(self, form):
if form.is_valid():
instance = form.save(commit=False)
instance.save()
return super(DogCreate, self).form_valid(form)
As you can see, my idea was to overwrite the clean method, by adding the correct Shelter to self.cleaned_data (based on the name the user put into the TextInputField). But this does not seem to work, because when pressing submit, the form is still declared invalid.
I think I have a rather uncommon feature here, at least I couldn't find a answer.
What I'd like to achieve is a text input with autocomplete on a related model with its label field. the given text should then get_or_create the related model. this already works but the problem is, that the new related model instance is saved on form submit no matter if the form is_valid or not.
given the following situation and implementation (shortened for better overview)
class Correspondent(models.Model):
label = models.CharField(_("label"), max_length=100, unique=True)
class Document(BaseModel):
correspondent = models.ForeignKey(
Correspondent,
verbose_name=_("correspondent"),
on_delete=models.PROTECT,
related_name="documents",
)
with the following form:
class DocumentForm(forms.ModelForm):
correspondent = forms.CharField(
label=_("correspondent"), widget=forms.TextInput(attrs={"class": "awesomplete"})
)
class Meta:
model = Document
exclude = ["created_by", "modified_by"]
def clean_correspondent(self, *args, **kwargs):
# ToDo: don't save the FKed instance if complete form isn't valid
user = self.initial["user"]
data = self.cleaned_data["correspondent"]
obj = Correspondent.objects.get_or_create(label=data)
return obj
so the problem here is obj.save() which is called before form.is_valid() and I couldn't figure a way yet how to solve this. I'd like to prevent the creation of a new Correspondent instance if the form isn't valid yet.
Let me know if I can improve this question and thx for any hints.
Thx to Dipen Dadhaniya for pushing me in the right direction.
I needed to exclude the actual field from the ModelForm so I could just clean in a more simple way as CharField needs it. Afterwards in the View I can do the logic, after the whole form is valid indeed.
the form looses the complete custom clean_correspondent method.
class DocumentForm(forms.ModelForm):
correspondent_label = forms.CharField(
label=_("correspondent"), widget=forms.TextInput(attrs={"class": "awesomplete"})
)
class Meta:
model = Document
exclude = ["correspondent", "created_by", "modified_by"]
the logic is now in the DocumentCreateView in the form_valid() method.
def form_valid(self, form):
form.instance.modified_by = self.request.user
form.instance.correspondent, created = Correspondent.objects.get_or_create(
label=form.cleaned_data["correspondent_label"]
)
return super().form_valid(form)
Bingo! :)
class A(Model):
to_b = ManyToManyField('B', blank=True, through='AtoB')
class B(Model):
to_a = ManyToManyField('A', blank=True, through='AtoB')
class AtoB(Model):
a = ForeignKey('A', on_delete=CASCADE)
b = ForeignKey('B', on_delete=CASCADE)
usr = ForeignKey(settings.USER, on_delete=CASCADE)
# some other fields
Im making a django application.
This is roughly equivalent to what i have in my models.py
I need m2m relation between A and B to go through another model because i need to store additional data there.
Now there is a problem - when i try to save instance of model A in my custom view, relations with B instances are not saved no matter whether i pick them or not.
And when i go to http://127.0.0.1:8000/admin and try to create instance of A from there, i dont even see proper field (should be <select multiple> i guess) for selecting relations with B.
Can someone please explain me why relations are not saved, and not even displayed in /admin?
Here is code roughly equivalent to what i have in views.py:
class Create(CreateView):
model = None # A or B
template_name = 'something.html'
def form_valid(self, form):
self.object = form.save(commit=False)
form.save()
return HttpResponseRedirect(self.get_success_url())
in urls.py i specify additional arguments like this:
views.Create.as_view(model=models.A, fields=['to_b'])
It is not going to work. If you are using your own ManytoMany intermediary table, you have to manually manage and save the objects yourself. Using Django's builtin functions won't work.
Save Object A, then save Object B and then save the relation in your AtoB table (which is also an object).
a_to_b = AtoB.objects.create(a=object_a, b=object_b, user=self.request.user)
print(a_to_b)
[...] Note that if you are using an intermediate
model for a many-to-many relationship, some of the related manager’s
methods are disabled, so some of these examples won’t work with such
models.
https://docs.djangoproject.com/en/1.10/topics/db/examples/many_to_many/
Your error is explained here: https://docs.djangoproject.com/en/1.10/topics/db/models/#intermediary-manytomany
I have come to an impasse when using a ModelForm.
I'm extending the User model that comes with Django, and I'm also using a ModelForm so the user can edit it.
Following the same example in the documentation, I would have this code.
models.py
class Employee(models.Model):
user = models.OneToOneField(User, on_delete=models.CASCADE)
# In this case, department is optional, so I have set 'blank' and 'null' to True.
department = models.CharField(max_length=100, blank=True, null=True)
forms.py
class DepartmentForm(ModelForm):
class Meta:
model = Employee
fields = ['department',]
The problem comes at the view. I found that I need to pass an instance of the model to the form so the save() function works without having to customize it, but of course, user.employee has not been created yet, therefore it throws an error.
views.py
def DepartmentView(request):
# Here is the issue.
department = request.user.employee
if request.method == 'POST':
# I need to pass the instance here.
form = DepartmentForm(request.POST, instance=department)
if form.is_valid():
form.save()
else:
# And also here so it autocompletes the form.
form = DepartmentForm(instance=department)
return render(request, 'employee.html', {'form': form})
It works if I manually add a value to user.employee.department through the shell and then reload the page, otherwise the error is as follow.
RelatedObjectDoesNotExist at [something]
User has no employee.
Or something like that... I'm sorry, I didn't try the code above so the error could be a little different, but the concept is exactly the same.
I'm also sorry if this has been asked before. I did a Google search and couldn't find an answer to this issue.
You could use get_or_create to fetch the employee from the db, or create it if it doesn't exist.
department, created = Employee.objects.get_or_create(user=request_or_user, department='')
if request.method == 'POST':
form = DepartmentForm(request.POST, instance=department)
...
Another option is to use a signal, so that the related model is created when the user is created. Then you can assume that the employee already exists, and you can use request.user.employee instead of get_or_create.
I need to implement the following:
The user shall be presented with a form that will have a drop down choice menu consisting of property names. There are two types of properties: general properties, i.e. properties common for all users and custom properties, i.e. properties that each user has defined prior to that. The models would look something like that:
class GeneralPropertyName(models.Model):
name = models.CharField(max_length=20)
class CustomPropertyName(models.Model):
user = models.ForeignKey(User)
name = models.CharField(max_length=20)
The drop down menu should have all general properties and only those custom properties that pertain to the user.
First question: how to define such a model?
I need to: 1. somehow unify both properties, 2. take only those items from CustomPropertyName that pertain to the user
class SpecData(models.Model):
user = models.ForeignKey(User)
selection_title = models.CharField(max_length=20)
property = ForeignKey(GeneralPropertyName) ??UNIFY??? ForeignKey(CustomPropertyName)
Second, is there anything special that needs to be done with ModelForm?
class SpecDataForm(ModelForm):
class Meta:
model = SpecData
And the 3rd question is what needs to be done in the view? I will need to use inline formsets since I will have a few dynamic forms like that.
def index(request):
user = User.objects.get(username=request.user.username)
specdataFormSet = inlineformset_factory(User, SpecData, form=SpecDataForm, extra=30)
...
specdata_formset = specdataFormSet(instance=user, prefix='specdata_set')
...
Thanks.
EDIT: Adjusted juliocesar's suggestion to include formsets. Somehow I am getting the following error message: Cannot resolve keyword 'property' into field. Choices are: id, name, selection_title, user
def index(request):
user = User.objects.get(username=request.user.username)
user_specdata_form = UserSpecDataForm(user=user)
SpecdataFormSet = inlineformset_factory(User, SpecData, form=user_specdata_form, extra=30)
You can use a GenericForeignKey to handle it, but you still need more to solve your further questions about forms and view.
I have made an example of how you solve your problem (logged user can select from General properties and his Custom properties, non-logged user only can select General properties). I used model inheritance for the properties (In your sample code it seems that a CustomPropertyName is a PropertyName with other fields). I think inheritance is an easier and a more basic concept than ContentTypes and it fits to your needs.
NOTE: I remove some code like imports to simplify the code.
1) models.py file:
class PropertyName(models.Model):
name = models.CharField(max_length=20)
def __unicode__(self):
return self.name
class CustomPropertyName(PropertyName): # <-- Inheritance!!
user = models.ForeignKey(User)
def __unicode__(self):
return self.name
class SpecData(models.Model):
user = models.ForeignKey(User)
selection_title = models.CharField(max_length=20)
property = models.ForeignKey(PropertyName)
NOTES: The field SpecData.property points to PropertyName since all properties are saved in the PropertyName's database table.
2) forms.py file:
from django import forms
from django.db.models import Q
from models import SpecData, PropertyName
def UserSpecDataForm(user=None):
UserPropertiesQueryset = PropertyName.objects.filter(Q(custompropertyname__user=None) | Q(custompropertyname__user__id=user.id))
class SpecDataForm(forms.ModelForm):
property = forms.ModelChoiceField(queryset=UserPropertiesQueryset)
class Meta:
model = SpecData
exclude = ('user',)
return SpecDataForm
NOTES: The trick here is to generate the form SpecDataForm dynamically, by filtering properties according the user specified in the parameter.
3) views.py file:
from forms import UserSpecDataForm
def index(request):
if request.POST:
form = UserSpecDataForm(request.user)(request.POST) # instance=user
if form.is_valid():
spec_data = form.save(commit=False)
spec_data.user = request.user
spec_data.save()
else:
form = UserSpecDataForm(request.user)()
return render_to_response('properties.html', {'form': form}, context_instance=RequestContext(request))
NOTES: Nothing special here, just a call to form.UserSpecDataForm(request.user) that returns the form class and then instantiate. Also setted the logged-in user to the object returned on save since It was excluded in the form to not show in front-end.
Following this basic example you can do the same with formsets if you need it.
UPDATE:
Formset can be used by adding following code to the view:
user_specdata_form = UserSpecDataForm(user=request.user)
SpecdataFormSet = inlineformset_factory(User, SpecData, form=user_specdata_form, extra=30)
The complete project sample can be downloaded from http://ge.tt/904Wg7O1/v/0
Hope this helps
1a) have you looked into django's ContentType framework this will allow you to have generic foreign keys and you can put restrictions on what types of models are acceptable to store in.
1b) I think that the validation for accepting what type of foreign key is acceptable shouldn't be in your model but should be part of your form validation before saving.
2) If you do use a model form you're going to have to define your own custom widget for the propery field. This means you're probably going to have to write you're own render function to render the html from the field. You should also define your own validation function on the form to make sure that only the appropriate data is acceptable to save.
3) I don't think you'll have to do anything you aren't already doing in the views
Use GenericForeignKey:
class SpecData(models.Model):
user = models.ForeignKey(User)
selection_title = models.CharField(max_length=20)
content_type = models.ForeignKey(ContentType)
object_id = models.PositiveIntegerField()
property = GenericForeignKey('content_type', 'object_id')
You can use this to combine the two fields(type & id) into a single choice field.
One way is that you have only one model, make user nullable:
class PropertyName(models.Model):
user = models.ForeignKey(User, null=True, blank=True)
name = models.CharField(max_length=20)
class SpecData(models.Model):
user = models.ForeignKey(User)
selection_title = models.CharField(max_length=20)
property = ForeignKey(PropertyName)
So, if user is not set, it is a general property. If it is set, it is related to this user.
However, please note that if you need unique property names, that NULL != NULL.
Of course, the suggested GenericForeignKey solution is better for some cases.
Also, you can easily make the normal (non-model) form with that you describe and separate form logic from model logic.