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?)
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())))
[NOTE: this answer is now pretty completely outdated - please see the discussion below it, and more recent answers].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