电子邮件表单编码验证器错误

Question

我想为我的一个项目创建一个支持国际化域名（IDN）的表单验证器。为此，我使用了Django项目中的一部分代码（http://code.djangoproject.com/svn/django/trunk/django/core/validators.py），但是我的代码里似乎有个小错误，我找不到。

class Email(formencode.validators.Email):
    def _to_python(self, value, state):
        try:
            return super(Email, self)._to_python(value, state)
        except formencode.Invalid as e:
            # Trivial case failed. Try for possible IDN domain-part

            print 'heywo !'

            if value and u'@' in value:
                parts = value.split(u'@')
                try:
                    parts[-1] = parts[-1].encode('idna')
                except UnicodeError:
                    raise e

                try:
                    super(Email, self)._to_python(u'@'.join(parts), state)
                except formencode.Invalid as ex:
                    raise ex

                return value
            else:
                raise e

当我尝试验证一个带有国际化域名的邮箱（比如：test@wääl.de）时，第一次调用时抛出的无效异常会被触发，而在第一次捕获异常后的代码部分却从来没有执行过（'heywo !' 这句话从来没有被打印出来）。

这里有个例子：

>>> from test.lib.validators import Email
>>> Email().to_python(u'test@zääz.de')
Traceback (most recent call last):
  File "<console>", line 1, in <module>
  File "/usr/local/lib/python2.6/dist-packages/FormEncode-1.2.3dev-py2.6.egg/formencode    /api.py", line 416, in to_python
    vp(value, state)
  File "/usr/local/lib/python2.6/dist-packages/FormEncode-1.2.3dev-py2.6.egg/formencode    /validators.py", line 1352, in validate_python
    value, state)
Invalid: The domain portion of the email address is invalid (the portion after the @: z\xe4\xe4z.de)

我到底做错了什么呢？

谢谢。

Answer 1

好的，我找到了答案。我之前把 _to_python 这个方法搞错了，应该用 validate_python。现在这个类看起来是：

class Email(formencode.validators.Email):
    def validate_python(self, value, state):
        try:
            super(Email, self).validate_python(value, state)
        except formencode.Invalid as e:
            # Trivial case failed. Try for possible IDN domain-part
            if value and u'@' in value:
                parts = value.split(u'@')
                try:
                    parts[-1] = parts[-1].encode('idna')
                except UnicodeError:
                    raise e

                try:
                    super(Email, self).validate_python(u'@'.join(parts), state)
                except formencode.Invalid as ex:
                    raise ex
            else:
                raise e

现在运行得非常好 :)