I have a Model as follows:
class TankJournal(models.Model):
user = models.ForeignKey(User)
tank = models.ForeignKey(TankProfile)
ts = models.IntegerField(max_length=15)
title = models.CharField(max_length=50)
body = models.TextField()
I also have a model form for the above model as follows:
class JournalForm(ModelForm):
tank = forms.IntegerField(widget=forms.HiddenInput())
class Meta:
model = TankJournal
exclude = ('user','ts')
I want to know how to set the default value for that tank hidden field. Here is my function to show/save the form so far:
def addJournal(request, id=0):
if not request.user.is_authenticated():
return HttpResponseRedirect('/')
# checking if they own the tank
from django.contrib.auth.models import User
user = User.objects.get(pk=request.session['id'])
if request.method == 'POST':
form = JournalForm(request.POST)
if form.is_valid():
obj = form.save(commit=False)
# setting the user and ts
from time import time
obj.ts = int(time())
obj.user = user
obj.tank = TankProfile.objects.get(pk=form.cleaned_data['tank_id'])
# saving the test
obj.save()
else:
form = JournalForm()
try:
tank = TankProfile.objects.get(user=user, id=id)
except TankProfile.DoesNotExist:
return HttpResponseRedirect('/error/')
You can use Form.initial
, which is explained here.
You have two options either populate the value when calling form constructor:
form = JournalForm(initial={'tank': 123})
or set the value in the form definition:
tank = forms.IntegerField(widget=forms.HiddenInput(), initial=123)
Other solution: Set initial after creating the form:
form.fields['tank'].initial = 123
If you are creating modelform from POST values initial can be assigned this way:
form = SomeModelForm(request.POST, initial={"option": "10"})
https://docs.djangoproject.com/en/1.10/topics/forms/modelforms/#providing-initial-values
or None
part is really not needed.
or None
part is needed. If the request is a GET request, request.POST will be an empty dictionary which is treated differently than None
in the Form init method. Please review Django documentation.
I had this other solution (I'm posting it in case someone else as me is using the following method from the model):
class onlyUserIsActiveField(forms.ModelForm):
def __init__(self, *args, **kwargs):
super(onlyUserIsActiveField, self).__init__(*args, **kwargs)
self.fields['is_active'].initial = False
class Meta:
model = User
fields = ['is_active']
labels = {'is_active': 'Is Active'}
widgets = {
'is_active': forms.CheckboxInput( attrs={
'class': 'form-control bootstrap-switch',
'data-size': 'mini',
'data-on-color': 'success',
'data-on-text': 'Active',
'data-off-color': 'danger',
'data-off-text': 'Inactive',
'name': 'is_active',
})
}
The initial is definded on the __init__
function as self.fields['is_active'].initial = False
As explained in Django docs, initial
is not default
.
The initial value of a field is intended to be displayed in an HTML . But if the user delete this value, and finally send back a blank value for this field, the initial value is lost. So you do not obtain what is expected by a default behaviour.
The default behaviour is : the value that validation process will take if data argument do not contain any value for the field.
To implement that, a straightforward way is to combine initial
and clean_<field>()
:
class JournalForm(ModelForm):
tank = forms.IntegerField(widget=forms.HiddenInput(), initial=123)
(...)
def clean_tank(self):
if not self['tank'].html_name in self.data:
return self.fields['tank'].initial
return self.cleaned_data['tank']
I hope this can help you:
form.instance.updatedby = form.cleaned_data['updatedby'] = request.user.id
I also encountered the need to set default values in the form during development. My solution is
initial={"":""}
form=ArticleModel(request.POST)
if form.has_changed():
data = {i: form.cleaned_data[i] for i in form.changed_data}
data.update({key: val for key, val in init_praram.items() if key not in form.changed_data})
use form.has_changed ,if form.fields is required you can use this method
Success story sharing
initial
passed to the actual form? In the actual form model, do we have to write as a parameter/argument?View.get_form
to set initial data. Any CBV with a FormMixin (basically all CBVs that create or edit data) can either use a class-levelinitial
variable (for unchanging defaults) or you can overrideFormMixin.get_initial()
to return a dict of initial values to be passed to the form's constructor (for dynamic defaults.)