1 from django.contrib.auth.models import User

     2 from django import forms

     3 

     4 from django.contrib.auth import authenticate

     5 

     6 class LoginForm(forms.ModelForm):

     7     """ a form to handle login.

     8     """

     9 

    10     class Meta:

    11         model = User

    12         fields = ['email', 'password']

    13 

    14     def clean_email(self):

    15         """ see if a user exists for this email.

    16         """

    17 

    18         email = self.cleaned_data['email']

    19         try:

    20             self.user = User.objects.get(email__iexact=email)

    21             return email

    22         except User.DoesNotExist:

    23             raise forms.ValidationError("Incorrect e-mail or password")

    24 

    25     def clean_password(self):

    26         """ now we know that the user exists.

    27         we see if he typed the password correctly.

    28         """

    29 

    30         password = self.cleaned_data['password']

    31         user = authenticate(self.user.username, password)

    32         if not user:

    33             raise forms.ValidationError("Incorrect e-mail or password")

    34         return password

    35