Validate nested form in Django -

i have userprofile model linked onetoone django user model. while adding user through form, wanted have 1 form both of those. found snippet that, , didn't have problem it, until wanted validate username. form isn't throwing validationerror, like to, returns error page valueerror: user not created because data didn't validate..

from understand (which wrong), current setup doesn't handle validationerrors nested form.

is there way add functionality? if not, how should tackle issue of having 1 form handle models?

code:

class cmuserform(forms.modelform):    password = forms.charfield(widget=forms.passwordinput(),                               required=false,                               help_text=_("leave empty if don't want "                                           "to change it"))     def clean_password(self):        data = self.cleaned_data['password']        if data.strip():            return make_password(data)        else:            # if password field empty, don't change            return self.instance.password      def clean_username(self):        username = self.cleaned_data['username']         if get_user_model().objects.filter(username=username).exists():            raise forms.validationerror(_('this username in use.'))        return username      class meta:         model = get_user_model()         fields = ('first_name', 'last_name', 'email', 'username', 'password', 'is_staff', 'is_active')   class cmuserprofileform(forms.modelform):     def __init__(self, *args, **kwargs):         # take user if updating, none if creating         try:             self.user = kwargs['instance'].user         except attributeerror:             self.user = none          user_kwargs = kwargs.copy()         user_kwargs['instance'] = self.user         self.uf = cmuserform(*args, **user_kwargs)          super(cmuserprofileform, self).__init__(*args, **kwargs)          self.fields.update(self.uf.fields)         self.initial.update(self.uf.initial)      class meta:         model = userprofile         exclude = ['user']      def save(self, *args, **kwargs):         # save user , pass userprofile         user = self.uf.save(*args, **kwargs)         self.instance.user = user         return super().save(*args, **kwargs) 

i implemented same today. learnt website tango django. http://www.tangowithdjango.com/book/chapters/login.html. provided code how achieved this. inbuilt user model checks if username exists or not. hope helpful.

class sam(models.model):       user = model.onetoonefield(user)       #custom fields apart inbuilt user model       region = models.charfield(max_length=10)       designation = models.charfield(max_length=10) #forms.py form models. created samprofileform  capture custom fields specific one's profile , samform capture password , hash later in view.  #please note didnt add username check here. inbuilt user us. verified it. class samform(forms.modelform):       #form model capture inbuilt fields of "user" model       password = forms.charfield(widget=passwordinput())       class meta:             model = user             fields = ('username', 'email', 'password', 'firstname', 'lastname') class samprofileform(forms.modelform):        #form model built custom fields in case region , designation        class meta:              model = sam              fields = ('desgination', 'mgr') def register(request):     registered = false     if request.method == 'post':          user_form = samform(data=request.post)          profile_form = samprofileform(request.post)          if user_form.is_valid() , profile_form.is_valid():             user = user_form.save()             user.set_password(user.password)             user.save()             profile = profile_form.save(commit=false)             profile.user = user             profile.save()             registered = true          else:             print user_form.errors, profile_form.errors    else:        user_form = samform()        profile_form = samprofileform()    template = loader.get_template('sam/register.html')    context = requestcontext(request, {             'user_form' : user_form, 'profile_form' : profile_form, 'registered' : registered,     })    return httpresponse(template.render(context))