I'm using Django forms in my website and would like to control the order of the fields.
Here's how I define my forms:
class edit_form(forms.Form):
summary = forms.CharField()
description = forms.CharField(widget=forms.TextArea)
class create_form(edit_form):
name = forms.CharField()
The name is immutable and should only be listed when the entity is created. I use inheritance to add consistency and DRY principles. What happens which is not erroneous, in fact totally expected, is that the name field is listed last in the view/html but I'd like the name field to be on top of summary and description. I do realize that I could easily fix it by copying summary and description into create_form and loose the inheritance but I'd like to know if this is possible.
Why? Imagine you've got 100 fields in edit_form and have to add 10 fields on the top in create_form - copying and maintaining the two forms wouldn't look so sexy then. (This is not my case, I'm just making up an example)
So, how can I override this behavior?
Edit:
Apparently there's no proper way to do this without going through nasty hacks (fiddling with .field attribute). The .field attribute is a SortedDict (one of Django's internal datastructures) which doesn't provide any way to reorder key:value pairs. It does how-ever provide a way to insert items at a given index but that would move the items from the class members and into the constructor. This method would work, but make the code less readable. The only other way I see fit is to modify the framework itself which is less-than-optimal in most situations.
In short the code would become something like this:
class edit_form(forms.Form):
summary = forms.CharField()
description = forms.CharField(widget=forms.TextArea)
class create_form(edit_form):
def __init__(self,*args,**kwargs):
forms.Form.__init__(self,*args,**kwargs)
self.fields.insert(0,'name',forms.CharField())
That shut me up :)
From Django 1.9+
Django 1.9 adds a new Form attribute, field_order, allowing to order the field regardless their order of declaration in the class.
class MyForm(forms.Form):
summary = forms.CharField()
description = forms.CharField(widget=forms.TextArea)
author = forms.CharField()
notes = form.CharField()
field_order = ['author', 'summary']
Missing fields in field_order keep their order in the class and are appended after the ones specified in the list. The example above will produce the fields in this order: ['author', 'summary', 'description', 'notes']
See the documentation: https://docs.djangoproject.com/en/stable/ref/forms/api/#notes-on-field-ordering
Up to Django 1.6
I had this same problem and I found another technique for reordering fields in the Django CookBook:
class EditForm(forms.Form):
summary = forms.CharField()
description = forms.CharField(widget=forms.TextArea)
class CreateForm(EditForm):
name = forms.CharField()
def __init__(self, *args, **kwargs):
super(CreateForm, self).__init__(*args, **kwargs)
self.fields.keyOrder = ['name', 'summary', 'description']
From Django 1.9: https://docs.djangoproject.com/en/1.10/ref/forms/api/#notes-on-field-ordering
Original answer: Django 1.9 will support this by default on the form with field_order:
class MyForm(forms.Form):
...
field_order = ['field_1', 'field_2']
...
https://github.com/django/django/commit/28986da4ca167ae257abcaf7caea230eca2bcd80
I used the solution posted by Selene but found that it removed all fields which weren't assigned to keyOrder. The form that I'm subclassing has a lot of fields so this didn't work very well for me. I coded up this function to solve the problem using akaihola's answer, but if you want it to work like Selene's all you need to do is set throw_away to True.
def order_fields(form, field_list, throw_away=False):
"""
Accepts a form and a list of dictionary keys which map to the
form's fields. After running the form's fields list will begin
with the fields in field_list. If throw_away is set to true only
the fields in the field_list will remain in the form.
example use:
field_list = ['first_name', 'last_name']
order_fields(self, field_list)
"""
if throw_away:
form.fields.keyOrder = field_list
else:
for field in field_list[::-1]:
form.fields.insert(0, field, form.fields.pop(field))
This is how I'm using it in my own code:
class NestableCommentForm(ExtendedCommentSecurityForm):
# TODO: Have min and max length be determined through settings.
comment = forms.CharField(widget=forms.Textarea, max_length=100)
parent_id = forms.IntegerField(widget=forms.HiddenInput, required=False)
def __init__(self, *args, **kwargs):
super(NestableCommentForm, self).__init__(*args, **kwargs)
order_fields(self, ['comment', 'captcha'])
It appears that at some point the underlying structure of field order was changed from a django specific SordedDict to a python standard OrderedDict
Thus, in 1.7 I had to do the following:
from collections import OrderedDict
class MyForm(forms.Form):
def __init__(self, *args, **kwargs):
super(MyForm, self).__init__(*args, **kwargs)
original_fields = self.fields
new_order = OrderedDict()
for key in ['first', 'second', ... 'last']:
new_order[key] = original_fields[key]
self.fields = new_order
I'm sure someone could golf that into two or three lines, but for S.O. purposes I think clearly showing how it works is better than cleaver.
You could also create a decorator to order fields (inspired by Joshua's solution):
def order_fields(*field_list):
def decorator(form):
original_init = form.__init__
def init(self, *args, **kwargs):
original_init(self, *args, **kwargs)
for field in field_list[::-1]:
self.fields.insert(0, field, self.fields.pop(field))
form.__init__ = init
return form
return decorator
This will ensure that all the fields passed to the decorator come first.
You can use it like this:
#order_fields('name')
class CreateForm(EditForm):
name = forms.CharField()
The accepted answer's approach makes use of an internal Django forms API that was changed in Django 1.7. The project team's opinion is that it should never have been used in the first place. I now use this function to reorder my forms. This code makes use of an OrderedDict:
def reorder_fields(fields, order):
"""Reorder form fields by order, removing items not in order.
>>> reorder_fields(
... OrderedDict([('a', 1), ('b', 2), ('c', 3)]),
... ['b', 'c', 'a'])
OrderedDict([('b', 2), ('c', 3), ('a', 1)])
"""
for key, v in fields.items():
if key not in order:
del fields[key]
return OrderedDict(sorted(fields.items(), key=lambda k: order.index(k[0])))
Which I use in classes like this:
class ChangeOpenQuestionForm(ChangeMultipleChoiceForm):
def __init__(self, *args, **kwargs):
super().__init__(*args, **kwargs)
key_order = ['title',
'question',
'answer',
'correct_answer',
'incorrect_answer']
self.fields = reorder_fields(self.fields, key_order)
For recent versions of Django (>=1.9), see the other answers' Form.field_order
See the notes in this SO question on the way Django's internals keep track of field order; the answers include suggestions on how to "reorder" fields to your liking (in the end it boils down to messing with the .fields attribute).
Alternate methods for changing the field order:
Pop-and-insert:
self.fields.insert(0, 'name', self.fields.pop('name'))
Pop-and-append:
self.fields['summary'] = self.fields.pop('summary')
self.fields['description'] = self.fields.pop('description')
Pop-and-append-all:
for key in ('name', 'summary', 'description'):
self.fields[key] = self.fields.pop(key)
Ordered-copy:
self.fields = SortedDict( [ (key, self.fields[key])
for key in ('name', 'summary' ,'description') ] )
But Selene's approach from the Django CookBook still feels clearest of all.
Based on an answer by #akaihola and updated to work with latest Django 1.5 as self.fields.insert is being depreciated.
from easycontactus.forms import *
from django import forms
class CustomEasyContactUsForm(EasyContactUsForm):
### form settings and configuration
CAPTHCA_PHRASE = 'igolf'
### native methods
def __init__(self, *args, **kwargs):
super(CustomEasyContactUsForm, self).__init__(*args, **kwargs)
# re-order placement of added attachment field
self.fields.keyOrder.insert(self.fields.keyOrder.index('captcha'),
self.fields.keyOrder.pop(self.fields.keyOrder.index('attachment'))
)
### field defintitions
attachment = forms.FileField()
In the above we are extending an EasyContactUsForm base class as it is defined in django-easycontactus package.
I built a form 'ExRegistrationForm' inherited from the 'RegistrationForm' from Django-Registration-Redux. I faced two issues, one of which was reordering the fields on the html output page once the new form had been created.
I solved them as follows:
1. ISSUE 1: Remove Username from the Registration Form: In my_app.forms.py
class ExRegistrationForm(RegistrationForm):
#Below 2 lines extend the RegistrationForm with 2 new fields firstname & lastname
first_name = forms.CharField(label=(u'First Name'))
last_name = forms.CharField(label=(u'Last Name'))
#Below 3 lines removes the username from the fields shown in the output of the this form
def __init__(self, *args, **kwargs):
super(ExRegistrationForm, self).__init__(*args, **kwargs)
self.fields.pop('username')
2. ISSUE 2: Make FirstName and LastName appear on top: In templates/registration/registration_form.html
You can individually display the fields in the order that you want. This would help in case the number of fields are less, but not if you have a large number of fields where it becomes practically impossible to actually write them in the form.
{% extends "base.html" %}
{% load i18n %}
{% block content %}
<form method="post" action=".">
{% csrf_token %}
#The Default html is: {{ form.as_p }} , which can be broken down into individual elements as below for re-ordering.
<p>First Name: {{ form.first_name }}</p>
<p>Last Name: {{ form.last_name }}</p>
<p>Email: {{ form.email }}</p>
<p>Password: {{ form.password1 }}</p>
<p>Confirm Password: {{ form.password2 }}</p>
<input type="submit" value="{% trans 'Submit' %}" />
</form>
{% endblock %}
The above answers are right but incomplete. They only work if all the fields are defined as class variables. What about dynamic form fields which have to be defined in the intitialiser (__init__)?
from django import forms
class MyForm(forms.Form):
field1 = ...
field2 = ...
field_order = ['val', 'field1', 'field2']
def __init__(self, val_list, *args, **kwargs):
super(MyForm, self).__init__(*args, **kwargs)
vals = zip(val_list, val_list)
self.fields['val'] = forms.CharField(choices=vals)
The above will never work for val but will work for field1 and field2 (if we reorder them). You might want to try defining field_order in the initialiser:
class MyForm(forms.Form):
# other fields
def __init__(self, val_list, *args, **kwargs):
super(MyForm, self).__init__(*args, **kwargs)
vals = zip(val_list, val_list)
self.fields['val'] = forms.CharField(choices=vals)
self.field_order = ['val', 'field1', 'field2']
but this will also fail because the field order is fixed before the call to super().
Therefore the only solution is the constructor (__new__) and set field_order to a class variable.
class MyForm(forms.Form):
# other fields
field_order = ['val', 'field1', 'field2']
def __new__(cls, val_list, *args, **kwargs):
form = super(MyForm, cls).__new__(cls)
vals = zip(val_list, val_list)
form.base_fields['val'] = forms.CharField(choices=vals)
return form
Related
I'm looking for some advice where to go from here. I've been working on making a Form, which dynamically generates its fields.
The form is working and generating everything correctly. However, I am having issues with how to save the actual form data. I'm looking for each field to save as a new item in a model.
The View Class from view.py
class MaintenanceCheckListForm(LoginRequiredMixin, FormView):
login_url = '/accounts/login'
template_name = 'maintenance/checklist.html'
form_class = MaintenanceCheckListForm
success_url = reverse_lazy('m-checklist')
def form_valid(self, form):
form.cleaned_data
for key, values in form:
MaintenanceCheckList.objects.create(
item = key,
is_compliant = values
)
return super().form_valid(form)
The Form from forms.py
class MaintenanceCheckListForm(forms.Form):
def __init__(self, *args, **kwargs):
super(MaintenanceCheckListForm, self).__init__(*args, **kwargs)
items = Maintenance_Item.objects.all()
CHOICES = (
('P','Compliant'),
('F','Non-Compliant'),
)
for item in items:
self.fields[str(item.name)] = forms.ChoiceField(
label=item.name,
choices=CHOICES,
widget=forms.RadioSelect,
initial='F',
)
The Model, from models.py
class MaintenanceCheckList(CommonInfo):
CHOICES = (
('P','Compliant'),
('F','Non-Compliant'),
)
id = models.AutoField(primary_key=True)
item = models.CharField(max_length=100)
is_compliant = models.CharField(max_length=20, choices= CHOICES)
I am having trouble accessing the data from the Form when it POST's. I've done some troubleshooting where I have set the values statically in the '''form_valid''' and it appears to generate the correct amounts of entires in the model. However the trouble begins when I attempt to insert the values from the POST.
I receieve the below error, which I believe it is trying to dump all the keys and values into a single item instead of looping over each key, value and creating the item.
DataError at /maintenance/checklist
value too long for type character varying(100)
Request Method: POST
Request URL: http://t1.localhost:8000/maintenance/checklist
Django Version: 3.1.6
Exception Type: DataError
Exception Value:
value too long for type character varying(100)
I'm fairly new to the world of Django (4 weeks and counting so far, and maybe 12 weeks into python). So any assistance would be amazing!
I believe you have somewhat gone on a tangent. There's a simpler solution of using Model formsets for what you want.
First if you want a custom form make that:
from django import forms
class MaintenanceCheckListComplianceForm(forms.ModelForm):
item = forms.CharField(widget = forms.HiddenInput())
is_compliant = forms.ChoiceField(
choices=MaintenanceCheckList.CHOICES,
widget=forms.RadioSelect,
initial='F',
)
class Meta:
model = MaintenanceCheckList
fields = ('item', 'is_compliant')
Next use it along with modelformset_factory in your views:
from django.forms import modelformset_factory
class MaintenanceCheckListFormView(LoginRequiredMixin, FormView): # Changed view name was a bit misleading
login_url = '/accounts/login'
template_name = 'maintenance/checklist.html'
success_url = reverse_lazy('m-checklist')
def form_valid(self, form):
instances = form.save()
return super().form_valid(form)
def get_form_kwargs(self):
kwargs = super().get_form_kwargs()
kwargs['queryset'] = MaintenanceCheckList.objects.none()
kwargs['initial'] = [{'item': obj['name'], 'is_compliant': 'F'} for obj in Maintenance_Item.objects.all().values('name')]
return kwargs
def get_form(self, form_class=None):
kwargs = self.get_form_kwargs()
extra = len(kwargs['initial'])
form_class = modelformset_factory(MaintenanceCheckList, form=MaintenanceCheckListComplianceForm, extra=extra)
return form_class(**kwargs)
Now in your template:
<form method="post">
{{ form }}
</form>
Or manually render it:
<form method="post">
{{ form.management_form }}
{% for sub_form in form %}
Item: {{ sub_form.item.value }}
{{ sub_form }}
{% endfor %}
</form>
Note: The above usage is a bit weird due to the naming of the formset variable as form by the FormView you should look into improving that a bit.
Note: Looking at the implementation it feels a bit weird to do this. I would advice you to redesign your models a bit. Perhaps a foreign key between your models? It basically feels like you have duplicate data with this implementation.
i'm taking values from database table in views file and has to render those values to a form in template file which is created by using the forms class and i have to show those values for some fields and make them immutable.
class OrderForm(forms.Form):
pid=forms.IntegerField()
pname=forms.CharField()
pprice=forms.FloatField()
person_name=forms.CharField(max_length=40)
emailid=forms.EmailField()
address=forms.CharField(max_length=40)
city=forms.CharField(max_length=20)
state=forms.CharField(max_length=20)
zip=forms.IntegerField()
card=forms.IntegerField()
exp= forms.DateField()
cvv=forms.IntegerField()
def order(request,pk):
pid=pk
user_name=request.user.username
qs=Product.objects.get(pid=pid)
pname=qs.pname.format()
list={'username':user_name,'pid':pid,'pname':pname}
form=OrderForm
return render(request,'order.html',{'data':list,'form':form})
i expect input filed with value that i passed by default which is immutable and when i submit i have to get same value i passed
Looks to me like you're better off using a ModelForm. It would be something like:
class OrderForm(forms.ModelForm)
class Meta:
model = Order
widgets = {
`immutable_field` : forms.TextInput(attrs={'readonly':True})
}
def order(request,pk):
pid=pk
user_name=request.user.username
qs=Product.objects.get(pid=pid)
pname=qs.pname.format()
list={'username':user_name,'pid':pid,'pname':pname}
form=OrderForm()
form.fields['immutable_field'] = "Some Value"
return render(request,'order.html',{'data':list,'form':form})
If you already have an order then you can prepopulate the fields with form=OrderForm(instance=order)
Make field as disable from Form init method and pass initial value from view section
class OrderForm(forms.Form):
pid=forms.IntegerField()
pname=forms.CharField()
pprice=forms.FloatField()
person_name=forms.CharField(max_length=40)
emailid=forms.EmailField()
address=forms.CharField(max_length=40)
city=forms.CharField(max_length=20)
state=forms.CharField(max_length=20)
zip=forms.IntegerField()
card=forms.IntegerField()
exp= forms.DateField()
cvv=forms.IntegerField()
def __init__(self, *args, **kwargs):
super().__init__(*args, **kwargs)
self.fields['username'].disabled = True
self.fields['pid'].disabled = True
self.fields['pname'].disabled = True
Here in view you can pass dictionary to form as initial value of fields.
def order(request,pk):
pid=pk
user_name=request.user.username
qs=Product.objects.get(pid=pid)
pname=qs.pname.format()
initial={'username':user_name,'pid':pid,'pname':pname}
form=OrderForm(initial=initial)
return render(request,'order.html',{'data':initla,'form':form})
I'm trying to generate an object that allows values to be stored in a standard unit, but displayed in different units based on the settings for the project. Below is an example where I need to be able to store the temperature of a room. I want the database value to be in Kelvin for ease of calulations, but want the users to be able to view/enter in F or C as the project requires.
The model can take the values from a form and convert them to Kelvin on save. I know this can be done in the form, but I have it here for other data entry methods. A striped down version of the model is as follows:
class Room(models.Model):
name = models.CharField(max_length=255)
temperature = models.FloatField(default=293.15)
def save(self, *args, **kwargs):
self.temperature = convert.temperature(self.temperature,
from_unit=self.plant.temperature_scale)
super(Room, self).save(*args, **kwargs)
I created a ModelForm to use in CreateView and UpdateView. I needed the ModelForm to limit the queryset for other fields (which works fine). Here I was able to convert the temperature field to the desired units for a new object in CreateView, but I can not seem to find the way to pull this off for an existing record
class RoomForm(ModelForm):
def __init__(self, plant, *args, **kwargs):
super (RoomForm,self ).__init__(*args,**kwargs)
self.fields['temperature'].initial = convert.temperature(
value=self.fields['temperature'].initial,
from_unit='K',
to_unit=self.fields['unit'].queryset[0].plant.temperature_scale)
self.instance.temperature = convert.temperature(
value=self.instance.temperature,
from_unit='K',
to_unit=self.fields['unit'].queryset[0].plant.temperature_scale)
class Meta:
model = Room
fields = ['name', 'temperature']
For good measure, here are the views that call this form.
class NewRoom(CreateView):
model = Room
form_class = RoomForm
def get_form_kwargs(self, **kwargs):
form_kwargs = super(NewRoom, self).get_form_kwargs(**kwargs)
form_kwargs["plant"] = Plant.objects.get(slug=self.kwargs['plant'])
return form_kwargs
class EditRoom(UpdateView):
model = Room
form_class = RoomForm
template_name_suffix = "_update_form"
def get_form_kwargs(self, **kwargs):
form_kwargs = super(EditRoom, self).get_form_kwargs(**kwargs)
form_kwargs["plant"] = Plant.objects.filter(slug=self.kwargs['plant'])
return form_kwargs
In the templates (not forms) I use this to display the temperature correctly.
{{ room.temperature|convert_temperature:room.plant.temperature_scale }}
I assume I need to supplement the part where the ModelForm imports the data from the database record, but I could not identify where this happens in the django.forms source code.
I tried calling this manually in the shell
>>> from rooms.models import *
>>> from rooms.forms import *
>>> room = Room.objects.first()
>>> form = RoomForm(room.plant, instance=room)
>>> form.instance.temperature
20.0
>>> form.as_p()
and the rendered form is as follows with the incorrect value for temperature
<p>
<label for="id_name">Name:
</label>
<input id="id_name" maxlength="255" name="name" type="text" value="Testing"
required />
</p>\n
<p>
<label for="id_temperature">Temperature:
</label>
<input id="id_temperature" name="temperature"
step="any" type="number" value="293.15" required />
</p>\n
I'm using Django version 1.10.3 if it's possible this is a bug.
While lucasnadalutti let me in the right spot, it did not manage to do the trick. Overriding the instance passed to the ModelForm.__init__ and calling it again after altering.
class RoomForm(ModelForm):
def __init__(self, plant, *args, **kwargs):
super(RoomForm, self).__init__(*args,**kwargs)
self.instance.temperature = convert.temperature(
value=self.instance.temperature,
from_unit='K', to_unit=self.fields['unit'].queryset[0].plant.temperature_scale)
# Override instance passed to __init__ and call super again
kwargs['instance'] = self.instance
super(RoomForm, self).__init__(*args, **kwargs)
class Meta:
model = Room
fields = ['name', 'temperature']
To modify data in your existing record before rendering, just do it in self.instance after calling the parent's __init__.
def __init__(self, plant, *args, **kwargs):
super(RoomForm,self ).__init__(*args,**kwargs)
self.instance.temperature = # ...
I have a form that I need to show my project outside the area of administration, some fields can not be edited but can see them.
To do this would be great "AdminReadonlyField" found in "django.contrib.admin.helpers" The problem is that you can not do.
I have tried to create some widget that can replace this complex class, but I can not get it to work properly with DateTiemField fields.
class UserUpdateForm(forms.ModelForm):
"""
We need field "date_joined" can not be edited but can see them
"""
class Meta:
model = User
fields = ('first_name', 'last_name',
'email', 'date_joined', 'slug')
def __init__(self, user, *args, **kwargs):
kwargs['instance'] = user
super(UserUpdateForm, self).__init__(*args, **kwargs)
self.fields['date_joined'].widget = widgets.CMDateTimeText()
def clean_date_joined(self):
instance = getattr(self, 'instance', None)
if instance and instance.pk:
return instance.date_joined
else:
return self.cleaned_data['date_joined']
My code, something is not right.
class CMDateTimeText(DateTimeBaseInput):
"""
A SplitDateTime Widget that has some admin-specific styling.
Hereda Field and Widget.
"""
format_key = 'DATETIME_FORMAT'
def __init__(self, attrs=None, format=None):
# Use slightly better defaults than HTML's 20x2 box
default_attrs = {'class': 'date_id'}
if attrs:
default_attrs.update(attrs)
super(CMDateTimeText, self).__init__(attrs=default_attrs, format=format)
def render(self, name, value, attrs=None):
if value is None:
value = ''
value = self._format_value(value)
final_attrs = self.build_attrs(attrs, name=name)
return format_html('<p{}>{}</p>', flatatt(final_attrs), conditional_escape(value))
Result image:
any idea how to do "AdminReadonlyField"" any view or form?
So after hours of looking for various solutions, I found out how to do it the Django way.
Simply add the attribute disabled to the field in the form (not the widget!):
# in __init__() with crispy-forms for instance
self.fields['field'].disabled = True
# as form field
field = forms.CharField(disabled=True)
And it works... Django is taking care of not saving the field, if some hacker tampered with it although it's disabled. Only works with Django 1.9+.
I'm using wtforms-alchemy in my Tornado application to render SQLAlchemy models to HTML forms like this:
class UserProfileForm(ModelForm):
class Meta:
model = models.User
only = ['username', 'first_name', 'last_name']
It works just fine, but the fields on the form are in order last_name, username, first_name, which could be kinda confusing to user. Is there a way to set specific order of generated form's fields?
I did what this post suggested, and its been working flawlessly for me.
Briefly, add a class keyword that specifies the correct ordering, then update _unbound_fields from iter with fields in correct order.
You should put rendering of form in template.
like
{{ form.username }}
{{ form.first_name }}
{{ form.last_name }}
Solution https://stackoverflow.com/a/18475322/892040 did not work for me when inheriting from ModelForm. However, this did work:
class ItemReview(ModelForm):
class Meta:
model = Item
_field_order = ['field1', 'field2']
def __init__(self, *args, **kwargs):
super(ItemReview, self).__init__(*args, **kwargs)
field_order = getattr(ItemReview, '_field_order')
visited = []
if field_order:
new_fields = OrderedDict()
for field_name in field_order:
if field_name in self._fields:
new_fields[field_name] = self._fields[field_name]
visited.append(field_name)
for field_name in self._fields:
if field_name in visited:
continue
new_fields[field_name] = self._fields[field_name]
self._fields = new_fields