add new forms example

mattmakai · mattmakai · commit 345fc5dd57e9 · 2019-06-30T13:39:00.000-04:00
diff --git a/content/pages/examples/django/django-forms.markdown b/content/pages/examples/django/django-forms.markdown
@@ -734,3 +734,124 @@ def to_bool(value):
     else:
         raise ValidationError("Invalid Boolean Value.")
 ```
+
+
+## Example 5 from django-registration (redux)
+[django-registration (redux)](https://github.com/macropin/django-registration)
+([project documentation](https://django-registration-redux.readthedocs.io/en/latest/))
+is a [Django](/django.html) code library for one-phase, two-phase and 
+three-phase registration flows. The code is available 
+[open source](https://github.com/macropin/django-registration/blob/master/LICENSE). 
+
+[**django-registration / registration / forms.py**](https://github.com/macropin/django-registration/blob/master/registration/forms.py)
+
+```python
+"""
+Forms and validation code for user registration.
+Note that all of these forms assume Django's bundle default ``User``
+model; since it's not possible for a form to anticipate in advance the
+needs of custom user models, you will need to write your own forms if
+you're using a custom model.
+"""
+from __future__ import unicode_literals
+
+~~from django import forms
+~~from django.contrib.auth.forms import UserCreationForm
+from django.utils.translation import ugettext_lazy as _
+
+from .users import UserModel
+from .users import UsernameField
+
+User = UserModel()
+
+
+~~class RegistrationForm(UserCreationForm):
+    """
+    Form for registering a new user account.
+    Validates that the requested username is not already in use, and
+    requires the password to be entered twice to catch typos.
+    Subclasses should feel free to add any additional validation they
+    need, but should avoid defining a ``save()`` method -- the actual
+    saving of collected user data is delegated to the active
+    registration backend.
+    """
+    required_css_class = 'required'
+~~    email = forms.EmailField(label=_("E-mail"))
+
+    class Meta:
+        model = User
+        fields = (UsernameField(), "email")
+
+
+class RegistrationFormUsernameLowercase(RegistrationForm):
+    """
+    A subclass of :class:`RegistrationForm` which enforces unique 
+    case insensitive usernames, make all usernames to lower case.
+    """
+    def clean_username(self):
+        username = self.cleaned_data.get('username', '').lower()
+        if User.objects.filter(**{UsernameField(): username}).exists():
+~~            raise forms.ValidationError(_\
+~~              ('A user with that username already exists.'))
+
+        return username
+
+
+class RegistrationFormTermsOfService(RegistrationForm):
+    """
+    Subclass of ``RegistrationForm`` which adds a required checkbox
+    for agreeing to a site's Terms of Service.
+    """
+~~    tos = forms.BooleanField(widget=forms.CheckboxInput,
+~~             label=_('I have read and agree to the Terms of Service'),
+~~             error_messages={'required': _\
+~~             ("You must agree to the terms to register")})
+
+
+class RegistrationFormUniqueEmail(RegistrationForm):
+    """
+    Subclass of ``RegistrationForm`` which enforces uniqueness of
+    email addresses.
+    """
+    def clean_email(self):
+        """
+        Validate that the supplied email address is unique for the
+        site.
+        """
+        if User.objects.filter(email__iexact=self.cleaned_data['email']):
+~~            raise forms.ValidationError(_\
+~~                ("This email address is already in use. " + \
+~~                 "Please supply a different email address."))
+        return self.cleaned_data['email']
+
+
+class RegistrationFormNoFreeEmail(RegistrationForm):
+    """
+    Subclass of ``RegistrationForm`` which disallows registration with
+    email addresses from popular free webmail services; moderately
+    useful for preventing automated spam registrations.
+    To change the list of banned domains, subclass this form and
+    override the attribute ``bad_domains``.
+    """
+    bad_domains = ['aim.com', 'aol.com', 'email.com', 'gmail.com',
+                   'googlemail.com', 'hotmail.com', 'hushmail.com',
+                   'msn.com', 'mail.ru', 'mailinator.com', 'live.com',
+                   'yahoo.com', 'outlook.com']
+
+    def clean_email(self):
+        """
+        Check the supplied email address against a list of known free
+        webmail domains.
+        """
+        email_domain = self.cleaned_data['email'].split('@')[1]
+        if email_domain in self.bad_domains:
+            raise forms.ValidationError(_("Registration using free " + \
+                "email addresses is prohibited. Please supply a " + \
+                "different email address."))
+        return self.cleaned_data['email']
+
+
+~~class ResendActivationForm(forms.Form):
+~~    required_css_class = 'required'
+~~    email = forms.EmailField(label=_("E-mail"))
+```
