I use a ModelForm and I want to set a max_value for an IntegerField without losing the other attributes which where created from the model (verbose_name, etc.).
This is my ModelForm:
class DataForm(ModelForm):
def __init__(self, *args, **kwargs):
super(DataForm, self).__init__(*args, **kwargs)
self.fields['start_range_points'].max_value = 1000
class Meta():
model = DataModel
This doesn't work, django does not apply the validation for large numbers. If I create the field in the following way the validation works but I lose the information which was created from the Model.
class DataForm(ModelForm):
start_range_points = forms.IntegerField(min_value=0, max_value=1000)
class Meta():
model = DataModel
What can I do to achieve something similar to attempt #1?
The validator for max_value is added in IntegerField's __init__ function if max_value is present. So you will need to manually add the validator, something like:
from django.core.validators import MaxValueValidator
class DataForm(ModelForm):
def __init__(self, *args, **kwargs):
super(DataForm, self).__init__(*args, **kwargs)
validators = [ v for v in self.fields['start_range_points'].validators if not isinstance(v, MaxValueValidator) ]
validators.append( MaxValueValidator(1000) )
self.fields['start_range_points'].validators = validators
class Meta():
model = DataModel
Related
I am struggling to create my custom generic view in django to easily create search pages for certain models. I'd like to use it like this:
class MyModelSearchView(SearchView):
template_name = 'path/to/template.html'
model = MyModel
fields = ['name', 'email', 'whatever']
which will result in a view that returns a search form on GET and both form and results on POST.
The fields specifies which fields of MyModel will be available for a user to search.
class SearchView(FormView):
def get_form(self, form_class=None):
# what I'v already tried:
class SearchForm(ModelForm):
class Meta:
model = self.model
fields = self.fields
return SearchForm()
def post(self, request, *args, **kwargs):
# perform searching and return results
The problem with the code above is that form will not be submitted if certain fields are not be properly filled. User should be allowed to provide only part of fields to search but with the code I provided the form generated with ModelForm prevents that (for example because a field in a model cannot be blank).
My questions are:
Is it possible to generate a form based on a model to omit this behaviour?
Or is there any simpler way to create SearchView class?
I don't want to manually write forms if it's possible.
One way to accomplish this is to set blank=True on the field in MyModel, as indicated in the docs:
If the model field has blank=True, then required is set to False on the form field. Otherwise, required=True.
But for this to be a generic solution, you can't count on being able to modify the model fields. You can instead set the fields' required attribute to False immediately after the instance is created:
class SearchForm(ModelForm):
class Meta:
model = self.model
fields = self.fields
def __init__(self, *args, **kwargs):
super().__init__(*args, **kwargs)
for (field_name, field) in self.fields.items():
field.required = False
Since you're using the ModelForm for searching, you should set all the fields as required=False, by overriding the __init__ method:
def get_form(self, form_class=None):
# what I'v already tried:
class SearchForm(ModelForm):
class Meta:
model = self.model
fields = self.fields
def __init__(self, *args, **kwargs):
super(SearchForm, self).__init__(*args, **kwargs)
for field in self.fields:
self.fields[field].required = False
return SearchForm()
Though I suggest you should user django-filter, which makes it easier and cleaner to filter your searches. First you need to install it:
pip install django-filter
Then add it to your INSTALLED_APPS. After that you can create a filters.py file in your app:
# myapp/filters.py
import django_filters as filters
from .models import MyModel
MyModelFilterSet(filters.FilterSet):
class Meta:
model = MyModel
fields = ['name', 'email', 'whatever']
By default it's going to filter with the __exact lookup. You can change this in a couple of ways, just take a look here and here. To know which lookups you can use, take a look here.
After creating your filters.py file you can add it to a View, like a ListView:
# myapp/views.py
from django.views.generic import ListView
from .filters import MyModelFilterSet
from .models import MyModel
class MyModelSearchView(ListView):
template_name = 'path/to/template.html'
model = MyModel
def get_queryset(self):
qs = self.model.objects.all()
filtered_model_list = MyModelFilterSet(self.request.GET, queryset=qs)
return filtered_model_list.qs
There's a lot more you can do with django-filter. Here's the full documentation.
Suppose I have following Model
class Member(models.Model):
name = ...
qualities = models.ManyToManyField(ProfessionalQuality, related_name='members')
And following form:
class CommonMemberForm(forms.ModelForm):
"""This form for gathering common features in both admin and member forms
"""
class Meta:
model = Member
fields = '__all__'
def __init__(self, *args, **kwargs):
super(CommonMemberForm, self).__init__(*args, **kwargs)
self.fields['qualities'].validators.append(...)
When I try to instantiate form, I get KeyError: 'qualities' are not in self.fields. Why is that?
This code works in admin.
What is the correct way of handling such fields?
Try this:
class CommonMemberForm(forms.ModelForm):
"""This form for gathering common features in both admin and member forms
"""
class Meta:
model = Member
fields = '__all__'
widgets = {
'qualities': forms.CheckboxSelectMultiple()
}
def __init__(self, *args, **kwargs):
super(CommonMemberForm, self).__init__(*args, **kwargs)
#self.fields['qualities'].widget...
This works for me:
class CommonMemberForm(AbstractUser):
class Meta:
model = Member
fields = '__all__'
def __init__(self, *args, **kwargs):
super(RegularUser, self).__init__(*args, **kwargs)
self._meta.get_field('qualities').validators = [validate_qualities]
Is there any way to load different admin forms for editing an objects depending of what object is needed to be updated?
For example - we have an MPTTModelAdmin objects. And for root objects we don't want to see some fields:
class RootObjectForm(ModelForm):
class Meta:
model = Author
exclude = ('title',)
class ChildObjectForm(ModelForm):
class Meta:
model = Author
fields = ('name', 'birth_date')
But I don't know how to get object fields in forms.py or admin.py.
You can always supply your own form class for a ModelAdmin class: https://docs.djangoproject.com/en/1.5/ref/contrib/admin/#django.contrib.admin.ModelAdmin.form
From there you can access fields by key, just like any other Django form:
class MyModelForm(forms.ModelForm):
class Meta:
model = MyModel
def __init__(self, *args, **kwargs):
super(MyModeForm, self).__init__(*args, **kwargs)
# access whatever field by key
# self.fields['field-name']
In forms.py file you can get object fields and their value at two stages.
1 : when form is submitted.
clean method does initial validations.
def clean(self):
""" validation of address form """
cleaned_data = super(WebsiteAddressForm, self).clean()
field1_value = self.cleaned_data.get("field1")
print field1_value
return cleaned_data
2 : when form is initialized. ____init____ method will call.
class MyForm(forms.ModelForm):
class Meta:
model = Model1
def __init__(self, *args, **kwargs):
super(MyForm, self).__init__(*args, **kwargs)
#self.fields['field1']
I'm using the Django Form View and I want to enter custom choices per user to my Choicefield.
How can I do this?
Can I use maybe the get_initial function?
Can I overwrite the field?
When I want to change certain things about a form such as the label text, adding required fields or filtering a list of choices etc. I follow a pattern where I use a ModelForm and add a few utility methods to it which contain my overriding code (this helps keep __init__ tidy). These methods are then called from __init__ to override the defaults.
class ProfileForm(forms.ModelForm):
class Meta:
model = Profile
fields = ('country', 'contact_phone', )
def __init__(self, *args, **kwargs):
super(ProfileForm, self).__init__(*args, **kwargs)
self.set_querysets()
self.set_labels()
self.set_required_values()
self.set_initial_values()
def set_querysets(self):
"""Filter ChoiceFields here."""
# only show active countries in the ‘country’ choices list
self.fields["country"].queryset = Country.objects.filter(active=True)
def set_labels(self):
"""Override field labels here."""
pass
def set_required_values(self):
"""Make specific fields mandatory here."""
pass
def set_initial_values(self):
"""Set initial field values here."""
pass
If the ChoiceField is the only thing you're going to be customising, this is all you need:
class ProfileForm(forms.ModelForm):
class Meta:
model = Profile
fields = ('country', 'contact_phone', )
def __init__(self, *args, **kwargs):
super(ProfileForm, self).__init__(*args, **kwargs)
# only show active countries in the ‘country’ choices list
self.fields["country"].queryset = Country.objects.filter(active=True)
You can then make your FormView use this form with like this:
class ProfileFormView(FormView):
template_name = "profile.html"
form_class = ProfileForm
In my ModelForm, I have to override some settings of the fields (e.g. choices, or required state). This requires declaring the entire field again as formfield.
Is there a simple way to access the verbose_name of the model field, so this doesn't have to redefined?
You don't have to redefine the field to change these settings. You can access the field in the form __init__ like below.
class MyForm(forms.ModelForm):
class Meta(object):
model = MyModel
def __init__(self, *args, **kwargs):
super(MyForm, self).__init__(*args, **kwargs)
self.fields['my_field'].required = True