User registration

users/forms.py

@@ -0,0 +1,53 @@
+from django.contrib.auth.forms import UserCreationForm as BaseUserCreationForm
+from django.core.validators import EmailValidator
+from django.contrib.auth import get_user_model
+from django.core.exceptions import ValidationError
+from django.contrib.auth import password_validation
+from django.forms import ModelForm
+
+
+UserModel = get_user_model()
+
+
+class UserCreationForm(BaseUserCreationForm):
+
+    def __init__(self, *args, **kwargs):
+        super().__init__(*args, **kwargs)
+        self.fields['username'].validators = [EmailValidator()]
+        self.fields['username'].label = "Email"
+
+        self.fields['username'].help_text = None  # "Email" is descriptive enough
+
+        # the other conditions will be "revealed" when you trip'em up. Arguably that's an UX anti-pattern, but so is
+        # having too many instructions. I'm erring on assuming my users are smart enough to pick a good password
+        # initially, and if they don't, at least they'll have only a single instruction to read. (bad password-pickers
+        # are probably bad readers too)
+        self.fields['password1'].help_text = "At least 8 characters"
+
+        self.fields['password2'].help_text = None  # "Confirm password" is descriptive enough
+
+    class Meta:
+        model = UserModel
+        fields = ("username",)
+
+    def _post_clean(self):
+        # copy of django.contrib.auth.forms.UserCreationForm._post_clean; but with password1 instead of password2; I'd
+        # say it's better UX to complain where the original error is made
+
+        ModelForm._post_clean(self)  # commented out because we want to skip the direct superclass
+        # Validate the password after self.instance is updated with form data
+        # by super().
+        password = self.cleaned_data.get("password1")
+        if password:
+            try:
+                password_validation.validate_password(password, self.instance)
+            except ValidationError as error:
+                self.add_error("password1", error)
+
+    def save(self, **kwargs):
+        commit = kwargs.pop("commit", True)
+        user = super().save(commit=False)
+        user.email = user.username
+        if commit:
+            user.save()
+        return user