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If I have a Django form such as:
class ContactForm(forms.Form): subject = forms.CharField(max_length=100) message = forms.CharField() sender = forms.EmailField()
And I call the as_table() method of an instance of this form, Django will render the fields as the same order as specified above.
My question is how does Django know the order that class variables where defined?
(Also how do I override this order, for example when I want to add a field from the classe’s init method?)
# forms.Form example class SignupForm(forms.Form): password = ... email = ... username = ... field_order = ['username', 'email', 'password'] # forms.ModelForm example class UserAccount(forms.ModelForm): custom_field = models.CharField(max_length=254) def Meta: model = User fields = ('username', 'email') field_order = ['username', 'custom_field', 'password']
[NOTE: this answer is now pretty completely outdated – please see the discussion below it, and more recent answers].
f is a form, its fields are
f.fields, which is a
django.utils.datastructures.SortedDict (it presents the items in the order they are added). After form construction f.fields has a keyOrder attribute, which is a list containing the field names in the order they should be presented. You can set this to the correct ordering (though you need to exercise care to ensure you don’t omit items or add extras).
Here’s an example I just created in my current project:
class PrivEdit(ModelForm): def __init__(self, *args, **kw): super(ModelForm, self).__init__(*args, **kw) self.fields.keyOrder = [ 'super_user', 'all_districts', 'multi_district', 'all_schools', 'manage_users', 'direct_login', 'student_detail', 'license'] class Meta: model = Privilege
I went ahead and answered my own question. Here’s the answer for future reference:
form.py does some dark magic using the
__new__ method to load your class variables ultimately into
self.fields in the order defined in the class.
self.fields is a Django
SortedDict instance (defined in
So to override this, say in my example you wanted sender to come first but needed to add it in an init method, you would do:
class ContactForm(forms.Form): subject = forms.CharField(max_length=100) message = forms.CharField() def __init__(self,*args,**kwargs): forms.Form.__init__(self,*args,**kwargs) #first argument, index is the position of the field you want it to come before self.fields.insert(0,'sender',forms.EmailField(initial=str(time.time())))
Fields are listed in the order they are defined in ModelClass._meta.fields. But if you want to change order in Form, you can do by using keyOrder function.
For example :
class ContestForm(ModelForm): class Meta: model = Contest exclude=('create_date', 'company') def __init__(self, *args, **kwargs): super(ContestForm, self).__init__(*args, **kwargs) self.fields.keyOrder = [ 'name', 'description', 'image', 'video_link', 'category']
With Django >= 1.7 your must modify
ContactForm.base_fields as below:
from collections import OrderedDict ... class ContactForm(forms.Form): ... ContactForm.base_fields = OrderedDict( (k, ContactForm.base_fields[k]) for k in ['your', 'field', 'in', 'order'] )
This trick is used in Django Admin
PasswordChangeForm: Source on Github
Form fields have an attribute for creation order, called
.fields attribute is a dictionary, so simple adding to dictionary and changing
creation_counter attributes in all fields to reflect new ordering should suffice (never tried this, though).
Use a counter in the Field class. Sort by that counter:
import operator import itertools class Field(object): _counter = itertools.count() def __init__(self): self.count = Field._counter.next() self.name="" def __repr__(self): return "Field(%r)" % self.name class MyForm(object): b = Field() a = Field() c = Field() def __init__(self): self.fields =  for field_name in dir(self): field = getattr(self, field_name) if isinstance(field, Field): field.name = field_name self.fields.append(field) self.fields.sort(key=operator.attrgetter('count')) m = MyForm() print m.fields # in defined order
[Field('b'), Field('a'), Field('c')]
class AuthorForm(ModelForm): class Meta: model = Author fields="__all__"
exclude are used:
class PartialAuthorForm(ModelForm): class Meta: model = Author exclude = ['title']
Then Django references the order of fields as defined in the model. This just caught me out, so I thought I’d mention it. It’s referenced in the ModelForm docs:
If either of these are used, the order the fields appear in the form will be the order the fields are defined in the model, with ManyToManyField instances appearing last.
As of Django 1.7 forms use OrderedDict which does not support the append operator. So you have to rebuild the dictionary from scratch…
class ChecklistForm(forms.ModelForm): class Meta: model = Checklist fields = ['name', 'email', 'website'] def __init__(self, guide, *args, **kwargs): self.guide = guide super(ChecklistForm, self).__init__(*args, **kwargs) new_fields = OrderedDict() for tier, tasks in guide.tiers().items(): questions = [(t['task'], t['question']) for t in tasks if 'question' in t] new_fields[tier.lower()] = forms.MultipleChoiceField( label=tier, widget=forms.CheckboxSelectMultiple(), choices=questions, help_text="desired set of site features" ) new_fields['name'] = self.fields['name'] new_fields['email'] = self.fields['email'] new_fields['website'] = self.fields['website'] self.fields = new_fields
For future reference: things have changed a bit since newforms. This is one way of reordering fields from base formclasses you have no control over:
def move_field_before(form, field, before_field): content = form.base_fields[field] del(form.base_fields[field]) insert_at = list(form.base_fields).index(before_field) form.base_fields.insert(insert_at, field, content) return form
Also, there’s a little bit of documentation about the SortedDict that
base_fields uses here: http://code.djangoproject.com/wiki/SortedDict
The easiest way to order fields in django 1.9 forms is to use
field_order in your form Form.field_order
Here is a small example
class ContactForm(forms.Form): subject = forms.CharField(max_length=100) message = forms.CharField() sender = forms.EmailField() field_order = ['sender','message','subject']
This will show everything in the order you specified in
fields in inner
Meta class is what worked for me on
#!/usr/bin/env python # -*- coding: utf-8 -*- """ Example form declaration with custom field order. """ from django import forms from app.models import AppModel class ExampleModelForm(forms.ModelForm): """ An example model form for ``AppModel``. """ field1 = forms.CharField() field2 = forms.CharField() class Meta: model = AppModel fields = ['field2', 'field1']
As simple as that.
I’ve used this to move fields about:
def move_field_before(frm, field_name, before_name): fld = frm.fields.pop(field_name) pos = frm.fields.keys().index(before_name) frm.fields.insert(pos, field_name, fld)
This works in 1.5 and I’m reasonably sure it still works in more recent versions.
It has to do with the meta class that is used in defining the form class. I think it keeps an internal list of the fields and if you insert into the middle of the list it might work. It has been a while since I looked at that code.
None of these answers worked for me, Actually, you do not have to do anything custom, you can just order the fields in the order you want in your Model class. For eg … the below code
from django.db import models class Student(models.Model): class Meta: verbose_name_plural = "categories" id = models.AutoField(primary_key=True) name = models.CharField(max_length=300) nick_name = models.CharField(max_length=300) created_at = models.DateTimeField(auto_now_add=True) updated_at = models.DateTimeField(auto_now=True) def __str__(self): return self.name
Your admin interface for model Will display the fields exactly in the same order in which you have declared in this case it will be
(id, name, nick_name )
To add something, you can use this (Django 3+):
class ...(forms.ModelForm): field = ... class Meta: model = Xxxxxx fields="__all__" field_order = ['field', '__all__']