Weird behaviour of form and widget in Django - django

I have following simple form field
class PhoneField(CharField):
widget = PhoneWidget
def clean(self, value):
value = re.sub('\D', '', super(PhoneField, self).clean(value))
if len(value) < 7:
raise ValidationError(_("Phone number is too short"), code='too_short')
return value
However, widget is still text input.
However, if I write
def __init__(self, *args, **kwargs):
kwargs['widget'] = PhoneWidget
super(PhoneField, self).__init__(*args, **kwargs)
Then it works perfectly. Digging in the code I noticed, that if widget is not specified in kwargs, then self.widget is used, but it is not a case. Why is that?
Note, that I don't pass widget in code.
field = PhoneField(label='Phone')

Found the problem.
The problem was in admin. Admin passed in kwargs default widget for CharField - widgets.AdminTextInputWidget.

Related

Django-Admin : Override add-URL of the Foreign Key Auto-Complete "add" button / + green cross

Is there a simple way of overriding/pass a parameter to the popup url automatically created by django-admin built-in autocomplete/select2 widget to create a new foreign key object? This url is embedded in the green cross (see picture).
I didn't come across any well described solutions.
So the default url is pointing towards admin/app/model/add/?_to_field=id&_popup=1 but I would like to add a parameter admin/app/model/add/?_to_field=id&_popup=1&field_1=100 in order to pre-populate some fieds on the popup add_view.
Any leads?
As per Maxim's answer :
def formfield_for_dbfield(self, db_field, request, **kwargs):
if db_field.name == "clinical_exam":
widget = super(ConsultationAdmin, self).formfield_for_dbfield(db_field, request, **kwargs).widget
widget.template_name = 'admin/related_widget_wrapper_with_id.html'
widget.attrs.update({'your_parameter': 'you can use it after in template'})
print(db_field)
return db_field.formfield(widget=widget)
return super(ConsultationAdmin, self).formfield_for_dbfield(db_field, request, **kwargs)
'change + -' this is a result of render RelatedFieldWidgetWrapper
from django.contrib.admin.widgets
You can change attributes of this widget, but it is a little bit complicated.
in ModelAdmin.formfield_for_dbfield:
def formfield_for_dbfield(self, *args, **kwargs):
widget = super.formfield_for_dbfield(self, *args, **kwargs).widget
if isinstance(widget, RelatedFieldWidgetWrapper):
old_context = widget.get_context
widget.get_context = my_function(widget.get_context, *args, **kwargs)
my function is a decorator for old function:
def my_function(func, *initargs, **initkwargs):
def wrapped(*args, **kwargs):
context = func(*args, **kwargs)
your_keys_vals_to_add_in_url = 'something in form key=val&'
context['url_params'] = f'{context['url_params']}&{your_keys_vals_to_add_in_url}'
return context
return wrapped
Other possibility is - to change template related_widget_wrapper.html
from django.admin.contrib.templates.admin.widgets
You can hardcoded your values there.
in ModelAdmin.formfield_for_dbfield:
def formfield_for_dbfield(self, *args, **kwargs):
widget = super.formfield_for_dbfield(self, *args, **kwargs).widget
if isinstance(widget, RelatedFieldWidgetWrapper):
widget.template_name = 'path/to/your_overriden_related_widget_wrapper.html'
widget.attrs.update('your_parameter' : 'you can use it after in template') # this is not work right now in django
and after it in own template:
# example for change link
# this is not work right now in django
<a ... data-href-template="{{ change_related_template_url }}?{{ url_params }}&{{ attr.your_parameter|dafault:'' }}" .. >
The last part not works in Django right now. I made an issue in Django project about this possibility.

Django dynamic forms - validating Select field

I am using Django 2.2
I am creating a form dynamically, by reading a JSON definition file; the configuration file specifies the types of widgets, permitted values etc.
I have come a bit unstuck with the Select widget however, because I prepend a '--' to the list of permitted values in the list (so that I will know when a user has not selected an item).
This is the code snippet where the Select widget is created:
class myForm(forms.Form):
def __init__(self, *args, **kwargs):
super().__init__(*args, **kwargs)
# ...
elif widget_type_id == WIDGET_TYPE_DROPDOWN:
CHOICES.insert(0,('-', INVALID_SELECTION))
form_field = CharField(label=the_label, widget=Select(choices=CHOICES),required=is_required)
My problem is that when the is_valid() method is invoked on my form, any rendered Select widgets are are accepted as valid regardless of the selection.
I want to implement code that has this logic (pseudocode below):
def is_valid(self):
for field_name, field in self.fields.items():
if isinstance(field.type, Select):
if field.required and field.selected_value == INVALID_SELECTION:
return False
return super().is_valid()
What would be the correct way to implement this functionality? For instance, how would I even get the selected values for the field (in the form code)?
Validate a form data: docs
by creating a custom Field with validation
a specific field by using fieldname_clean()
by overriding clean()
by using validators
? What would be the correct way to implement this functionality?
I've deviated a bit from the pseudocode in what you've asked
Validators docs
There are already many buitin validators. For this purpose, create a custom validator which checks the value in the field and raise ValidationError.
Create validator.py in your app
# validator.py
from django.core.exceptions import ValidationError
def validate_select_option(value):
if value == '-':
raise ValidationError('Invalid selection')
In forms.py import validate_select_option and add validator to the field
# forms.py
from .validator import validate_select_option
# other parts of code
form_field = CharField(label=the_label, widget=Select(choices=CHOICES), required=is_required, validator=[validate_select_option])
This validator validate_select_option can now be used not only to the field which has choices but also to any other field to validate. Anyhow, that's not its intend. So can be used to any fields with choices :)
Since you said that you are creating the form dynamically and I'm assuming that you can add additional options to Field using JSON definition file. For fieldname_clean() and clean() you will need to add these methods in your Form class. Custom field can be created and imported into. But, I think simple validators can do this easily.
? how would I even get the selected values for the field (in the form code)
If Form class method clean(self, *args, **kwargs) and fieldname_clean(self, *args, **kwargs) are used : you can access the form data by self.cleaned_data dictionary. cleaned_data is created only after is_valid().
While overriding is_valid , in-order to access the form data, we need to call the parent validation first and then work on it.
def is_valid(self, *args, **kwargs):
# cannot access self.cleaned_data since it is not created yet
valid = super(myForm, self).is_valid()
# can access self.cleaned_data since it has been created when parent is_valid() has been called
for fieldname, field in self.fields.items():
if isinstance(field, forms.CharField): # the type of widget is not considered.
if fieldname in self.cleaned_data and field.required and self.cleaned_data[fieldname] == '-':
valid = False
return valid
It's kind of hidden because you're using a CharField with a Select widget but if you look at the ChoiceField documentation it says that the empty value should be an empty string.
Assuming the form field is required=True, you should just be able to change your empty value tuple to ('', INVALID_SELECTION).
CHOICES having already values. I insert ('INVALID_SELECTION', 'INVALID_SELECTION') this. And check if the value of form_field field is INVALID_SELECTION then add error in same field. Else form is submited.
views.py
class DynamicFormView(View):
template_name = 'test.html'
def get(self, request, *args, **kwargs):
form = myForm( request.POST or None)
context = {
'form' : form,
}
return render(request, self.template_name, context)
def post(self, request,id = None, *args, **kwargs):
context = {}
form = myForm(request.POST or None,)
if form.is_valid():
if request.POST['form_field'] == 'INVALID_SELECTION':
form.add_error("form_field",_("This field is required."))
else:
form.save()
context = {
'form' : form,
}
return render(request, self.template_name, context)
forms.py
class myForm(forms.Form):
CHOICES = [
('FR', 'Freshman'),
('SO', 'Sophomore'),
('JR', 'Junior'),
('SR', 'Senior'),
('GR', 'Graduate'),
]
CHOICES.insert(0,('INVALID_SELECTION', 'INVALID_SELECTION'))
form_field = forms.ChoiceField(label='the_label',choices=CHOICES,widget=forms.Select(attrs={'class':' form-control'}),required = False)
def __init__(self, *args, **kwargs):
super().__init__(*args, **kwargs)
def save(self):
# form is success
pass
class Meta:
model = Student
urls.py
path('dyanmic-form/create/', views.DynamicFormView.as_view(), name='dyanamic_form_create'),
Sorry my bad english language.

How to set initial data for Django admin model add instance form?

How can I set an initial value of a field in the automatically generated form for adding a Django model instance, before the form is displayed? I am using Django 1.3.1.
My model is the following:
class Foo(models.Model):
title = models.CharField(max_length=50)
description = models.TextField()
and the current admin form is really nothing special
class FooAdmin(admin.ModelAdmin):
ordering = ('title',)
When I use the admin page to add a new instance of Foo, I get a nice form with empty fields for title and description. What I would like is that the description field is set with a template that I obtain by calling a function.
My current best attempt at getting there is this:
def get_default_content():
return 'this is a template for a Foo description'
class FooAdminForm(django.forms.ModelForm):
class Meta:
model = Foo
def __init__(self, *args, **kwargs):
kwargs['initial'].update({'description': get_default_content()})
super(FooAdminForm, self).__init__(self, *args, **kwargs)
class FooAdmin(admin.ModelAdmin):
ordering = ('title',)
form = FooAdminForm
but if I try this I get this Django error:
AttributeError at /admin/bar/foo/add/
'FooForm' object has no attribute 'get'
Request Method: GET
Request URL: http://localhost:8000/admin/bar/foo/add/
Django Version: 1.3.1
Exception Type: AttributeError
Exception Value: 'FooForm' object has no attribute 'get'
Exception Location: /www/django-site/venv/lib/python2.6/site-packages/django/forms/widgets.py in value_from_datadict, line 178
I don't know what is wrong here, and what I should do to make it work. What I also find strange about this error (apart from the fact that I see it at all) is that there is no FooForm in my code at all?
Alasdair's approach is nice but outdated. Radev's approach looks quite nice and as mentioned in the comment, it strikes me that there is nothing about this in the documentation.
Apart from those, 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'}
You need to include self as the first argument in your __init__ method definition, but should not include it when you call the superclass' method.
def __init__(self, *args, **kwargs):
# We can't assume that kwargs['initial'] exists!
if 'initial' not in kwargs:
kwargs['initial'] = {}
kwargs['initial'].update({'description': get_default_content()})
super(FooAdminForm, self).__init__(*args, **kwargs)
Having said that, a model field can take a callable for its default, so you may not have to define a custom admin form at all.
class Foo(models.Model):
title = models.CharField(max_length=50)
description = models.TextField(default=get_default_content)
More then 3 years later,
But actually what you should do is override admin.ModelAdmin formfield_for_dbfield .. like this:
class FooAdmin(admin.ModelAdmin):
def formfield_for_dbfield(self, db_field, **kwargs):
field = super(FooAdmin, self).formfield_for_dbfield(db_field, **kwargs)
if db_field.name == 'description':
field.initial = 'My initial description'
elif db_field.name == 'counter':
field.initial = get_counter() + 1
return field
Cheers;
When adding new objects, it is convenient to use get_changeform_initial_data() as suggested by Wtower.
However, when changing existing objects, that does not work (see source).
In that case, you could extend ModelAdmin.get_form() as follows (using the OP's example):
def get_form(self, request, obj=None, change=False, **kwargs):
if obj and not obj.description:
obj.description = get_default_content()
return super().get_form(request, obj, change, **kwargs)

Django send key or value from the view to the form class

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 :)

Django AdminForm field default value

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'