So in the Django admin I have an object change form like so:
class SurveyChoiceField(forms.ModelChoiceField):
def label_from_instance(self, obj):
return u'{0} - {1}'.format(obj.id, obj.name)
class BlahAdminForm(forms.ModelForm):
def __init__(self, *args, **kwargs):
super(BlahAdminForm, self).__init__(*args, **kwargs)
surveys = Survey.objects.filter(deleted=False).order_by('-id')
self.fields['survey'] = SurveyChoiceField(queryset=surveys)
class BlahAdmin(admin.ModelAdmin):
form = BlahAdminForm
and I would like to limit the dropdown to surveys of a certain type based on the blah. Something like
blah_id = self.blah.id
blah_survey_type = Blah.objects.filter(id=blah_id).get('survey_type')
surveys = Survey.objects.filter(deleted=False, type=blah_survey_type).order_by('-id')
but I'm not sure how to get the id of the Blah in the BlahAdminForm class.
A Django ModelForm has an instance which is the Blah instance it will create or edit. In case you edit an instance, the instance is passed through the instance parameter when creating the form. In case you create a new instance, then the instance is typically constructed in the super(BlahAdminForm, self).__init__(..) call (but has an id equal to None, since it is not yet saved).
You thus can obtain a reference to the instance that the form is editing, or a its id with:
class BlahAdminForm(forms.ModelForm):
def __init__(self, *args, **kwargs):
super(BlahAdminForm, self).__init__(*args, **kwargs)
blah_id = self.instance.id
# ...
You can thus use this self.instance in the constructor, or in other methods to inspect (and alter) the instance the form is handling.
Related
It seems like if a ModelForm is given an instance, it ignores any values you provide for initial and instead sets it to the value of the instance -- even if that instance is an empty model record.
Is there any way to create a form with an instance and have it set initial data?
I need it because I'm saving related records and they don't appear to save correctly unless the ModelForm is given an instance when created.
I'm sure the answer to this is straightforward and I'm just missing something obvious.
Here is the relevant code:
in the view:
form = form_class(person=person, conference=conference, initial=initial, instance=registration)
where form_class is RegistrationForm and then in the registration form:
class RegisterForm(forms.ModelForm):
... fields here ...
def __init__(self, *args, **kwargs):
... other code ...
self.person = kwargs.pop('person')
super(RegisterForm, self).__init__(*args, **kwargs)
for key, in self.fields.keys():
if hasattr(self.person, key):
self.fields[k].initial = getattr(self.person, key)
Then when I call the field, the related fields are empty.
Figured this out after a little bit of googling.
You have to set the initial value before calling super.
So instead of looping through self.fields.keys(), I had to type out the list of fields that I wanted and looped through that instead:
class RegisterForm(forms.ModelForm):
... fields here ...
initial_fields = ['first_name', 'last_name', ... ]
def __init__(self, *args, **kwargs):
... other code ...
self.person = kwargs.pop('person')
for key in self.initial_fields:
if hasattr(self.person, key):
self.fields[k].initial = getattr(self.person, key)
super(RegisterForm, self).__init__(*args, **kwargs)
#Daria rightly points out that you don't have self.fields before calling super. I'm pretty sure this will work:
class RegisterForm(forms.ModelForm):
... fields here ...
initial_fields = ['first_name', 'last_name', ... ]
def __init__(self, *args, **kwargs):
... other code ...
initial = kwargs.pop('initial', {})
self.person = kwargs.pop('person')
for key in self.initial_fields:
if hasattr(self.person, key):
initial[key] = initial.get(key) or getattr(self.person, key)
kwargs['initial'] = initial
super(RegisterForm, self).__init__(*args, **kwargs)
In this version, we use the initial argument to pass the values in. It's also written so that if we already have a value in initial for that field, we don't overwrite it.
Sounds to me that you may be looking for a bound form. Not entirely sure, I'm trying to unpick a similar issue:
Django forms can be instantiated with two arguments which control this kind of thing. As I understand it:
form = MyForm(initial={...}, data={...}, ...)
initial will set the possible values for the fields—like setting a queryset—data will set the actual (or selected) values of a form and create a bound form. Maybe that is what you want. Another, tangental, point you might find interesting is to consider a factory method rather than a constructor, I think the syntax is more natural:
class MyForm(forms.ModelForm):
...
#staticmethod
def makeBoundForm(user):
myObjSet = MyObject.objects.filter(some_attr__user=user)
if len(myObjSet) is not 0:
data = {'myObject': myObjSet[0]}
else:
raise ValueError()
initial = {'myObject': myObjSet}
return MyForm(initial=initial, data=data)
You can also pass extra variables to the class when initializing it. The values you pass can then override initial or POST data.
class RegisterForm(forms.ModelForm):
... fields here ...
def __init__(self, person, conference, *args, **kwargs):
... other code ...
super(RegisterForm, self).__init__(*args, **kwargs)
self.fields['person'] = person
self.fields['conference'] = conference
form = RegisterForm(person, conference, initial=initial, instance=registration)
Use ModelAdmin.get_changeform_initial_data. For example, if you add initial data for form field "report_datetime"
def get_changeform_initial_data(self, request):
initial_data = super().get_changeform_initial_data(request)
initial_data.update(report_datetime=<my_initial_datetime>)
return initial_data
Works for 3.2+. I'm not sure about older versions.
See django docs
I have a form which contains a choicefield called level allowing the selection of value between 0-3 who's options I want to "limit" dynamically. Is this possible?
pseudo-code for the view would contain something like this:
form = new instance of myform
allowed_level = 2
form.level maximum value =< allowed_level
Sure, you can dynamically set the validation criteria when creating the form: (beware: this isn't a complete example as I'm not sure of your setup)
class MyForm(forms.Form):
level = ...
def __init__(self, *args, **kwargs, allowed_level=None):
self.allowed_level = allowed_level
super(MyForm, self).__init__(*args, **kwargs)
def clean_level(self):
data = self.cleaned_data['level']
# Here you can play with what you want to allow
if level > self.allowed_level:
raise forms.ValidationError("A problem with level value")
return data
and just use your view normally
def my_view(request, ...):
form = MyForm(allowed_level=2)
if form.is_valid():
...
I've just created a forms.models.BaseInlineFormSet to override the default formset for a TabularInline model. I need to evaluate the user's group in formset validation (clean) because some groups must write a number inside a range (0,20).
I'm using django admin to autogenerate the interface.
I've tried getting the request and the user from the kwargs in the init method, but I couldn't get the reference.
This is what I have now:
class OrderInlineFormset(forms.models.BaseInlineFormSet):
def __init__(self, *args, **kwargs):
self.user = kwargs.pop('user')
super(OrderInlineFormset, self).__init__(*args, **kwargs)
def clean(self):
# get forms that actually have valid data
count = 0
for form in self.forms:
try:
if form.cleaned_data:
count += 1
if self.user.groups.filter(name='Seller').count() == 1:
if form.cleaned_data['discount'] > 20:
raise forms.ValidationError('Not authorized to specify a discount greater than 20%')
except AttributeError:
# annoyingly, if a subform is invalid Django explicity raises
# an AttributeError for cleaned_data
pass
if count < 1:
raise forms.ValidationError('You need to specify at least one item')
class OrderItemInline(admin.TabularInline):
model = OrderItem
formset = OrderInlineFormset
Then I use it as inlines = [OrderItemInline,] in my ModelAdmin.
Unfortunatly self.user is always None so I cannot compare the user group and the filter is not applied. I need to filter it because other groups should be able to specify any discount percent.
How can I do? If you also need the ModelAdmin code I'll publish it (I just avoided to copy the whole code to avoid confusions).
Well, I recognise my code there in your question, so I guess I'd better try and answer it. But I would say first of all that that snippet is really only for validating a minimum number of forms within the formset. Your use case is different - you want to check something within each form. That should be done with validation at the level of the form, not the formset.
That said, the trouble is not actually with the code you've posted, but with the fact that that's only part of it. Obviously, if you want to get the user from the kwargs when the form or formset is initialized, you need to ensure that the user is actually passed into that initialization - which it isn't, by default.
Unfortunately, Django's admin doesn't really give you a proper hook to intercept the initialization itself. But you can cheat by overriding the get_form function and using functools.partial to wrap the form class with the request argument (this code is reasonably untested, but should work):
from functools import partial
class OrderForm(forms.ModelForm):
def __init__(self, *args, **kwargs):
self.user = kwargs.pop('user')
super(OrderForm, self).__init__(*args, **kwargs)
def clean(self)
if self.user.groups.filter(name='Seller').count() == 1:
if self.cleaned_data['discount'] > 20:
raise forms.ValidationError('Not authorized to specify a discount greater than 20%')
return self.cleaned_data
class MyAdmin(admin.ModelAdmin):
form = OrderForm
def get_form(self, request, obj=None, **kwargs):
form_class = super(MyAdmin, self).get_form(request, obj, **kwargs)
return functools.partial(form_class, user=request.user)
Here's another option without using partials. First override the get_formset method in your TabularInline class.
Assign request.user or what ever extra varaibles you need to be available in the formset as in example below:
class OrderItemInline(admin.TabularInline):
model = OrderItem
formset = OrderInlineFormset
def get_formset(self, request, obj=None, **kwargs):
formset = super(OrderProductsInline, self).get_formset(request, obj, **kwargs)
formset.user = request.user
return formset
Now the user is available in the formset as self.user
class OrderInlineFormset(forms.models.BaseInlineFormSet):
def clean(self):
print(self.user) # is available here
I am writing an Edit form, where some fields already contain data. Example:
class EditForm(forms.Form):
name = forms.CharField(label='Name',
widget=forms.TextInput(),
initial=Client.objects.get(pk=??????)) #how to get the id?
What I did for another form was the following (which does not work for the case of the previous EditForm):
class AddressForm(forms.Form):
address = forms.CharField(...)
def set_id(self, c_id):
self.c_id = c_id
def clean_address(self):
# i am able to use self.c_id here
views.py
form = AddressForm()
form.set_id(request.user.get_profile().id) # which works in the case of AddressForm
So what is the best way to pass an id or a value to the form, and that could be used in all forms for that session/user?
Second: is it right to use initial to fill in the form field the way I am trying to do it?
You need to override the __init__ method for your form, like so:
def __init__(self, *args, **kwargs):
try:
profile = kwargs.pop('profile')
except KeyError:
super(SelectForm, self).__init__(*args, **kwargs)
return
super(SelectForm, self).__init__(*args, **kwargs)
self.fields['people'].queryset = profile.people().order_by('name')
and, obviously, build your form passing the right parameter when needed :)
I have a Django admin form.
And now I want to fill it's initial field with data based on my model. So I tried this:
class OrderForm(forms.ModelForm):
class Meta:
model = Order
email = CharField(initial="null", widget=Textarea(attrs={'rows': 30, 'cols': 100}))
def __init__(self, *args, **kwargs):
self.request = kwargs.pop('request', None)
products = kwargs['instance'].products.all()
self.message = purchase_message % (
"".join(["<li>" + p.name + ": " + str(p.price) + "</li>" for p in products]),
reduce(lambda x, y:x + y.price, products, 0)
)
# and here I have a message in self.message variable
super(OrderForm, self).__init__(*args, **kwargs)
At this point i don't know how to access email field to set it's initial value before widget is rendered. How can i do this?
Assuming the value is based on 'request' you should use this:
class MyModelAdmin(admin.ModelAdmin):
def get_form(self, request, obj=None, **kwargs):
form = super(MyModelAdmin, self).get_form(request, obj, **kwargs)
form.base_fields['my_field_name'].initial = 'abcd'
return form
Since Django 1.7 there is a function get_changeform_initial_data in ModelAdmin that sets initial form values:
def get_changeform_initial_data(self, request):
return {'name': 'custom_initial_value'}
EDIT: Apart from that, #Paul Kenjora's answer applies anyway, which might be useful if you already override get_form.
In case of inline (InlineModelAdmin) there is no get_changeform_initial_data. You can override get_formset and set formset.form.base_fields['my_field_name'].initial.
I'm not too sure what you need to set email to, but You can set the initial values in lots of different places.
Your function def init() isn't indented correctly which i guess is a typo? Also, why are you specifically giving the email form field a TextInput? It already renders this widget by default
You can set the email's initial value in your form's initialized (def __ init __(self))
(self.fields['email'].widget).initial_value = "something"
or in the model.py
email = models.CharField(default="something")
or as you have in forms.py
email = models.CharField(initial="something")
I needed the first solution of pastylegs since the other ones overwrite the whole Widget including, for example, the help text. However, it didn't work for me as he posted it. Instead, I had to do this:
self.fields['email'].initial = 'something'
In my case, I was trying to do a personalized auto-increment(based on current data and not a simple default) in a field of a django admin form.
This code is worked for me (Django 1.11):
from django import forms
class MyAdminForm(forms.ModelForm):
def __init__(self, *args, **kwargs):
super().__init__(*args, **kwargs)
self.initial['field_name'] = 'initial_value'