如果提交的表单的值是某个单词，django 如何做某事

Question

好的，所以我有 django 模型并创建了该模型的一种形式。这是我的模板：

<form method="post" action="">{% csrf_token %}
    {{ form.first_name }} {{form.last_name }} <br>
    {{ form.username }} {{ form.password }} <br>
    {{ form.date_of_birth_month }} {{ form.date_of_birth_day }} {{ form.date_of_birth_year }}
    <input type="submit" value="Register"/>
</form>


{% for field, error in form.errors.items %}
    {% if forloop.counter == 1 %}
        {{ error | striptags }}
    {% endif %}
{% endfor %}

现在，这是我的那种形式的模型。

class Users(models.Model): 
    months = (
        ('Month','Month'), ('January', 'January'), ('February','February'), ('March','March'), ('April','April'), ('May','May'), ('June','June'), ('July','July'), ('August','August'), ('September','September'), ('October','October'), ('November','November'), ('December','December'),
)
    days = (
        ('Day', 'Day'), ('1','1'), ('2','2'), ('3','3'), ('4','4'), ('5','5'),)
    years = (
        ('Year','Year'), ('2013','2013'), ('2012','2012'), ('2011','2011'), ('2010','2010'), ('2009','2009'), ('2008','2008'),)

    user_id = models.AutoField(unique=True, primary_key=True)
    username = models.SlugField(max_length=50, unique=True)
    first_name = models.CharField(max_length=50)
    last_name = models.CharField(max_length=50)
    password = models.SlugField(max_length=50)

    date_of_birth_month = models.CharField(verbose_name='', max_length=9, choices=months, default='Month')
    date_of_birth_day = models.CharField(verbose_name='', max_length=3, choices=days, default='Day')
    date_of_birth_year = models.CharField(verbose_name='', max_length=4, choices=years, default='Year')

现在，月份选择框的默认值为“月份”，用户名单击下拉菜单并选择他出生的月份。日和年也是如此。然而，这使得月、日和年成为用户可以选择的选项。我怎样才能做到这一点，如果用户选择“月”作为月份，“日”作为日或“年”作为年，然后引发错误消息说“请选择有效的月/日/年”？

我的观点在这里：

def home_page(request):
    form = UsersForm()
    if request.method == "POST":
        form = UsersForm(request.POST)

        if form.is_valid():
            form.save()
    c = {}
    c.update(csrf(request))
    c.update({'form':form})
    return render_to_response('home_page.html', c)

Answer 1

为表单中的字段编写 clean 方法：

class UsersForm(form.Form):
    # form fields here

    def clean_month(self):
        month = self.cleaned_data.get('month')
        if month:
            try:
                month = int(month)
            except:
                raise forms.ValidationError('Invalid month')
            if month < 1 or month > 12:
                raise forms.ValidationError('Invalid month')

        return month

对您要验证的其余字段执行此操作。更多帮助在Documentation