验证并显示自定义Django表单中的错误

Question

当我使用 form.as_p 来显示我的表单时，比如说我点击提交按钮却没有填写任何字段，它会显示错误信息，提醒我填写必填项。不过，当我自定义我的 HTML 模板时，它就不会验证字段，也不会显示任何错误信息。我的 forms.py 文件是这样的：

# forms.py
    class SignUpForm(forms.ModelForm):
    username = forms.CharField(label='Username', max_length=75, widget=forms.TextInput(attrs={'placeholder' : 'Username'}))
    email = forms.EmailField(label='Email', max_length=255)
    first_name = forms.CharField(label='First Name', max_length=75)
    last_name = forms.CharField(label='Last Name', max_length=75)
    birthday = forms.DateField(label='Birthday')
    gender = forms.ChoiceField(choices = User.GENDER_CHOICES)

    class Meta:
        model = User
        fields = ['username', 'password', 'email', 'first_name', 'last_name', 'birthday', 'gender']
        widgets = {
            'password': forms.PasswordInput(attrs={'class': 'form-control'}),
            'email': forms.EmailInput(attrs={'class': 'form-control'}),
            'birthday': forms.DateInput(attrs={'class': 'form-control'}),
        }

    def save(self, commit=True):
        user = super(SignUpForm, self).save(commit=False)
        user.username = self.cleaned_data['username']
        user.set_password(self.cleaned_data['password'])
        user.email = self.cleaned_data['email']
        user.first_name = self.cleaned_data['first_name']
        user.last_name = self.cleaned_data['last_name']
        user.birthday = self.cleaned_data['birthday']
        user.gender = self.cleaned_data['gender']
        if commit:
            user.save()
        return user

我的 HTML 模板是这样的：

# registration.html
<form class="form-signin" action="/register/" method="post">
    <h2 class="form-signin-heading">registration now</h2>
    <div class="login-wrap">
        <p>Enter your personal details below</p>
        <input type="text" class="form-control" placeholder="{{ form.first_name.label }}" name="{{ form.first_name.name }}" id="id_{{ form.first_name.name }}" maxlength="75" autofocus>
        <input type="text" class="form-control" placeholder="{{ form.last_name.label }}" name="{{ form.last_name.name }}" id="id_{{ form.last_name.name }}" maxlength="75" autofocus>
        <input type="text" class="form-control" placeholder="{{ form.email.label }}" name="{{ form.email.name }}" id="id_{{ form.email.name }}" maxlength="255" autofocus>

        <div class="radios">
            {% for choice in form.gender.field.choices %}
                <label class="label_radio col-lg-4 col-sm-4" for="">
                    <input name="{{ form.gender.name }}" id="radio-01" value="{{choice.0}}" type="radio" checked /> {{ choice.1 }}
                </label>
            {% endfor %}
        </div>

        <p> Enter your account details below</p>
        <input type="text" class="form-control" placeholder="{{ form.username.label }}" name="{{ form.username.name }}" id="id_{{ form.username.name }}" autofocus>
        <input type="password" class="form-control" placeholder="{{ form.password.label }}" name="{{ form.password.name }}" id="id_{{ form.password.name }}">
        <label class="checkbox">
            <input type="checkbox" value="agree this condition"> I agree to the Terms of Service and Privacy Policy
        </label>
        <input class="btn btn-lg btn-login btn-block" type="submit" value="Submit"/>

        <div class="registration">
            Already Registered.
            <a class="" href="login.html">
                Login
            </a>
        </div>
    </div>
  </form>

我现在刚开始学习 Django，我看过关于自定义表单的文档，但没有找到关于如何像 forms.as_p 那样验证字段的信息。

Answer 1

你现在的做法是不对的，生成自定义的HTML表单应该用Django提供的表单字段，比如{{ form.first_name }}这些，而不是自己手动写HTML代码。

不过，问题其实更简单：你忘了在每个字段后面加上{{ form.myfield.errors }}来显示错误信息，还有在表单顶部加上{{ form.non_field_errors }}来显示整体的错误信息。

另外，没必要在save里做那么多额外的工作。那些字段已经由父类处理好了，你只需要手动处理user.set_password这一部分就可以了。