Django 1.9 检查电子邮件是否已经存在

Question

我的站点设置为没有用户名（或者更确切地说是 user.username = user.email）。如果用户尝试输入数据库中已经存在的用户名，Django 会出现错误消息，但是由于我没有使用用户名进行注册，所以我无法弄清楚如何执行此操作。

就像默认设置一样，我不想重新加载页面来查看是否有一个电子邮件地址已经与用户关联。我的猜测是使用 Ajax，但我不知道该怎么做。我看过其他帖子，但最近似乎没有任何内容。

我如何检查一个电子邮件地址是否已经存在，如果存在，给一个错误信息让用户输入一个新的电子邮件地址？

models.py：

class MyUsers(models.Model):
    user = models.OneToOneField(User)
    first_name = models.CharField(max_length=100, blank=True)
    last_name = models.CharField(max_length=100, blank=True)
    email = models.EmailField(max_length=100, blank=True, unique=True)
    company = models.CharField(max_length=100, blank=True, null=True)
    website = models.URLField(max_length=100, blank=True, null=True)
    phone_number = models.CharField(max_length=100, blank=True, null=True)

    def __str__(self):
        return self.user.username

forms.py：

class UserForm(forms.ModelForm):
    class Meta:
        model = User
        fields = ('email',)


class UserProfileForm(forms.ModelForm):
    class Meta:
        model = UserProfile
        fields = ('first_name', 'last_name', 'company', 'website', 'phone_number')

views.py：

def index(request):
    registered = False

    if request.method == 'POST':
        user_form = UserForm(data=request.POST)
        profile_form = UserProfileForm(data=request.POST)

        if user_form.is_valid() and profile_form.is_valid():
            user = user_form.save()
            user.set_password(user.password)
            user.password = ""
            user.username = user.email
            user.save()

            profile = profile_form.save(commit=False)
            profile.user = user
            profile.email = user.email
            profile.save()

            user.first_name = profile.first_name
            user.last_name = profile.last_name
            user.save()

            registered = True
            return HttpResponseRedirect(reverse('registration'))
        else:
            print user_form.errors, profile_form.errors
    else:
        user_form = UserForm()
        profile_form = UserProfileForm1()

    context = {'user_form': user_form, 'profile_form': profile_form, 'registered': registered}
    return render(request, 'mysite/register.html', context)

register.html:

{% extends 'mysite/base.html' %}
{% load staticfiles %}

{% block title_block %}
    Register
{% endblock %}

{% block head_block %}
{% endblock %}

{% block body_block %}    
    <form id="user_form" method="post" action="/mysite/" enctype="multipart/form-data">
        {% csrf_token %}
        {{ user_form.as_p }}
        {{ profile_form.as_p }}

        <input type="submit" name="submit" value="Register" />
    </form>
{% endblock %}

Answer 1

您可以覆盖UserForm 上的clean_<INSERT_FIELD_HERE>() 方法来检查这种特殊情况。它看起来像这样：

forms.py:

class UserForm(forms.ModelForm):
    class Meta:
        model = User
        fields = ('email',)

    def clean_email(self):
        # Get the email
        email = self.cleaned_data.get('email')

        # Check to see if any users already exist with this email as a username.
        try:
            match = User.objects.get(email=email)
        except User.DoesNotExist:
            # Unable to find a user, this is fine
            return email

        # A user was found with this as a username, raise an error.
        raise forms.ValidationError('This email address is already in use.')

class UserProfileForm(forms.ModelForm):
    class Meta:
        model = UserProfile
        fields = ('first_name', 'last_name', 'company', 'website', 'phone_number')

您可以在Django documentation 关于表单中阅读有关清理表单中特定字段的更多信息。

也就是说，我认为您应该考虑创建一个 custom user model 而不是将您的 User Profile 类视为 User 的包装器。