How can I change a Django form field value before saving?
Question:
if request.method == 'POST':
userf = UsersModelForm(request.POST)
username = userf.data['username']
password = userf.data['password']
passwordrepeat = userf.data['passwordrepeat']
email = userf.data['email']
I tried this:
tempSalt = bcrypt.gensalt()
password = bcrypt.hashpw(password,tempSalt)
passwordrepeat = bcrypt.hashpw(passwordrepeat,tempSalt)
userf.data['password'] = password
userf.data['passwordrepeat'] = passwordrepeat
But i got error. How can i change the value of userf.data['password']
and userf.data['passwordrepeat']
before saving?
Error:
AttributeError at /register
This QueryDict instance is immutable
Request Method: POST
Request URL: http://127.0.0.1:8000/register
Django Version: 1.3.1
Exception Type: AttributeError
Exception Value:
This QueryDict instance is immutable
Exception Location: /usr/local/lib/python2.6/dist-packages/django/http/__init__.py in _assert_mutable, line 359
Python Executable: /usr/bin/python
Python Version: 2.6.6
Python Path:
['/home/user1/djangoblog',
'/usr/lib/python2.6',
'/usr/lib/python2.6/plat-linux2',
'/usr/lib/python2.6/lib-tk',
'/usr/lib/python2.6/lib-old',
'/usr/lib/python2.6/lib-dynload',
'/usr/local/lib/python2.6/dist-packages',
'/usr/lib/python2.6/dist-packages',
'/usr/lib/python2.6/dist-packages/gst-0.10',
'/usr/lib/pymodules/python2.6',
'/usr/lib/pymodules/python2.6/gtk-2.0']
Answers:
Override _clean
methods and put your checks in them. You can modify cleaned_data
from there.
E.g:
def clean_password(self):
new1 = self.cleaned_data['password']
return new1
Every fields in the form will have a field_name_clean()
method created automatically by Django. This method is called when you do form.is_valid()
.
See the documentation for the save()
method
if request.method == 'POST':
userf = UsersModelForm(request.POST)
new_user = userf.save(commit=False)
username = userf.cleaned_data['username']
password = userf.cleaned_data['password']
passwordrepeat = userf.cleaned_data['passwordrepeat']
email = userf.cleaned_data['email']
new_user.password = new1
new_user.passwordrepeat = new2
new_user.save()
If you need to do something to the data before saving, just create a function like:
def clean_nameofdata(self):
data = self.cleaned_data['nameofdata']
# do some stuff
return data
All you need is to create a function with the name **clean_***nameofdata* where nameofdata is the name of the field, so if you want to modify password field, you need:
def clean_password(self):
if you need to modify passwordrepeat
def clean_passwordrepeat(self):
So inside there, just encrypt your password and return the encrypted one.
I mean:
def clean_password(self):
data = self.cleaned_data['password']
# encrypt stuff
return data
so when you valid the form, the password would be encrypted.
You will have problems if you need to fill form from POST, change any form field value and render form again.
Here is solution for it:
class StudentSignUpForm(forms.Form):
step = forms.IntegerField()
def set_step(self, step):
data = self.data.copy()
data['step'] = step
self.data = data
And then:
form = StudentSignUpForm(request.POST)
if form.is_valid() and something():
form.set_step(2)
return render_to_string('form.html', {'form': form})
In Views:
def post(self, request, *args, **kwargs):
form = self.form_class(request.POST)
if form.is_valid():
obj = form.save(commit=False)
obj.my_field = 'value'
obj.save()
In Forms:
instance = form.instance
instance.user = request.user
instance.save()
But be careful, this does not check is_valid()
. If you want to do that, you can instantiate the form with the new values:
# NOT TESTED, NOT SURE IF THIS WORKS...
form = MyForm(instance=instance)
if form.is_valid():
form.save()
if request.method == 'POST':
userf = UsersModelForm(request.POST)
username = userf.data['username']
password = userf.data['password']
passwordrepeat = userf.data['passwordrepeat']
email = userf.data['email']
I tried this:
tempSalt = bcrypt.gensalt()
password = bcrypt.hashpw(password,tempSalt)
passwordrepeat = bcrypt.hashpw(passwordrepeat,tempSalt)
userf.data['password'] = password
userf.data['passwordrepeat'] = passwordrepeat
But i got error. How can i change the value of userf.data['password']
and userf.data['passwordrepeat']
before saving?
Error:
AttributeError at /register
This QueryDict instance is immutable
Request Method: POST
Request URL: http://127.0.0.1:8000/register
Django Version: 1.3.1
Exception Type: AttributeError
Exception Value:
This QueryDict instance is immutable
Exception Location: /usr/local/lib/python2.6/dist-packages/django/http/__init__.py in _assert_mutable, line 359
Python Executable: /usr/bin/python
Python Version: 2.6.6
Python Path:
['/home/user1/djangoblog',
'/usr/lib/python2.6',
'/usr/lib/python2.6/plat-linux2',
'/usr/lib/python2.6/lib-tk',
'/usr/lib/python2.6/lib-old',
'/usr/lib/python2.6/lib-dynload',
'/usr/local/lib/python2.6/dist-packages',
'/usr/lib/python2.6/dist-packages',
'/usr/lib/python2.6/dist-packages/gst-0.10',
'/usr/lib/pymodules/python2.6',
'/usr/lib/pymodules/python2.6/gtk-2.0']
Override _clean
methods and put your checks in them. You can modify cleaned_data
from there.
E.g:
def clean_password(self):
new1 = self.cleaned_data['password']
return new1
Every fields in the form will have a field_name_clean()
method created automatically by Django. This method is called when you do form.is_valid()
.
See the documentation for the save()
method
if request.method == 'POST':
userf = UsersModelForm(request.POST)
new_user = userf.save(commit=False)
username = userf.cleaned_data['username']
password = userf.cleaned_data['password']
passwordrepeat = userf.cleaned_data['passwordrepeat']
email = userf.cleaned_data['email']
new_user.password = new1
new_user.passwordrepeat = new2
new_user.save()
If you need to do something to the data before saving, just create a function like:
def clean_nameofdata(self):
data = self.cleaned_data['nameofdata']
# do some stuff
return data
All you need is to create a function with the name **clean_***nameofdata* where nameofdata is the name of the field, so if you want to modify password field, you need:
def clean_password(self):
if you need to modify passwordrepeat
def clean_passwordrepeat(self):
So inside there, just encrypt your password and return the encrypted one.
I mean:
def clean_password(self):
data = self.cleaned_data['password']
# encrypt stuff
return data
so when you valid the form, the password would be encrypted.
You will have problems if you need to fill form from POST, change any form field value and render form again.
Here is solution for it:
class StudentSignUpForm(forms.Form):
step = forms.IntegerField()
def set_step(self, step):
data = self.data.copy()
data['step'] = step
self.data = data
And then:
form = StudentSignUpForm(request.POST)
if form.is_valid() and something():
form.set_step(2)
return render_to_string('form.html', {'form': form})
In Views:
def post(self, request, *args, **kwargs):
form = self.form_class(request.POST)
if form.is_valid():
obj = form.save(commit=False)
obj.my_field = 'value'
obj.save()
In Forms:
instance = form.instance
instance.user = request.user
instance.save()
But be careful, this does not check is_valid()
. If you want to do that, you can instantiate the form with the new values:
# NOT TESTED, NOT SURE IF THIS WORKS...
form = MyForm(instance=instance)
if form.is_valid():
form.save()