我编写了一个应用程序，它使用表单收集信息，然后通过电子邮件发送。其中许多表单都有一个文件字段，用于将文件附加到电子邮件。我想验证两件事，文件的大小(以确保我们的邮件服务器接受电子邮件。我还想检查文件扩展名，以阻止附加对我们的用户不可用的文件类型。
(这是我试图扩展的 python 类)
class FileField(Field):
widget = FileInput
default_error_messages = {
'invalid': _(u"No file was submitted. Check the encoding type on the form."),
'missing': _(u"No file was submitted."),
'empty': _(u"The submitted file is empty."),
'max_length': _(u'Ensure this filename has at most %(max)d characters (it has %(length)d).'),
}
def __init__(self, *args, **kwargs):
self.max_length = kwargs.pop('max_length', None)
super(FileField, self).__init__(*args, **kwargs)
def clean(self, data, initial=None):
super(FileField, self).clean(initial or data)
if not self.required and data in EMPTY_VALUES:
return None
elif not data and initial:
return initial
# UploadedFile objects should have name and size attributes.
try:
file_name = data.name
file_size = data.size
except AttributeError:
raise ValidationError(self.error_messages['invalid'])
if self.max_length is not None and len(file_name) > self.max_length:
error_values = {'max': self.max_length, 'length': len(file_name)}
raise ValidationError(self.error_messages['max_length'] % error_values)
if not file_name:
raise ValidationError(self.error_messages['invalid'])
if not file_size:
raise ValidationError(self.error_messages['empty'])
return data
最佳答案
只需重载“clean”方法即可:
def clean(self, data, initial=None):
try:
if data.size > somesize:
raise ValidationError('File is too big')
(junk, ext) = os.path.splitext(data.name)
if not ext in ('.jpg', '.gif', '.png'):
raise ValidationError('Invalid file type')
except AttributeError:
raise ValidationError(self.error_messages['invalid'])
return FileField.clean(self, data, initial)
关于python - 扩展表单字段以添加新的验证，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/2733740/