使用Flas从WTForm发送电子邮件验证

Question

我正在学习http://code.tutsplus.com/tutorials/intro-to-flask-adding-a-contact-page--net-28982中的烧瓶教程，目前正在进行验证步骤：

旧版本有以下内容：

from flask.ext.wtf import Form, TextField, TextAreaField, SubmitField, validators, ValidationError

class ContactForm(Form):
name = TextField("Name",  [validators.Required("Please enter your name.")])
email = TextField("Email",  [validators.Required("Please enter your email address."), validators.Email("Please enter your email address.")])
submit = SubmitField("Send")

阅读注释时，我将其更新为：（用InputRequired替换了验证器。必需）

(same fields)  

class ContactForm(Form):  
name = TextField("Name", validators=[InputRequired('Please enter your name.')])
email = EmailField("Email",  validators=[InputRequired("Please enter your email address.")]), validators.Email("Please enter your email address.")])
submit = SubmitField("Send")

我唯一的问题是我不知道该怎么处理validators.Email。我得到的错误消息是：

NameError: name 'validators' is not defined

我看过文档，也许我没有深入研究，但似乎找不到电子邮件验证的示例。

Answer 1

此错误的原因是，您很可能使用from foo import barimport语句导入了不带命名空间的验证器。

要使其更具可读性并修复示例代码中的语法错误，请执行以下操作：

from flask.ext.wtf import Form
from wtforms import TextField, SubmitField
from wtforms.validators import InputRequired, Email
from wtforms.fields.html5 import EmailField  

class ContactForm(Form):  
    name = TextField("Name", validators=[InputRequired('Please enter your name.')])
    email = EmailField("Email",  validators=[InputRequired("Please enter your email address."), Email("Please enter your email address.")])
    submit = SubmitField("Send")

这只在字段TextField、SubmitField和Email中加载，并且只在InputRequired和Email验证器中加载。然后简单地在validators关键字参数中链接验证器，就可以了。或者，正如@Mehdi Sadeghi在代码中指出的，直接提供一个验证器列表作为字段的第二个参数，在这种情况下，您的电子邮件字段将如下所示：

email = EmailField("Email", [InputRequired("Please enter your email address."), Email("Please enter your email address.")])

注意，通过使用语法from foo import bar只导入所需内容，您将丢弃模块名称空间，正如您在删除validators.前缀时注意到的那样。有些人发现，最好离开这个名称空间，然后使用点表示法，这样做只是为了防止可能的名称冲突，并立即查看对象所属的模块（无需回顾import语句）。

一如既往，选择权在你！

Answer 2

试试这个：

from flask.ext.wtf import Form
from wtforms import validators
from wtforms.fields.html5 import EmailField

class ContactForm(Form):
    email = EmailField('Email address', [validators.DataRequired(), validators.Email()])

Answer 3

我复习了同样的教程（我已经好几年没看烧瓶了）。

问题是由于0.9版本的烧瓶WTF发生了变化。Here他们说：

Note: From version 0.9.0, Flask-WTF will not import anything from wtforms, you need to import fields from wtforms.

要直接导入，forms.py应为：

from flask.ext.wtf import Form
from wtforms import StringField, TextAreaField, SubmitField
from wtforms.validators import InputRequired, Email

class ContactForm(Form):
  name = StringField("Name",  [InputRequired("Please enter your name.")])
  email = StringField("Email",  [InputRequired("Please enter your email address."), Email("This field requires a valid email address")])
  subject = StringField("Subject",  [InputRequired("Please enter a subject.")])
  message = TextAreaField("Message",  [InputRequired("Not including a message would be stupid")])
  submit = SubmitField("Send")

注意StringField替换TextField，并且InputRequiredis preferred overDataRequired。直接导入验证器是个人偏好，而不是导入整个命名空间。这也适用于：from wtforms import *和表单类：name = StringField("Name", [validators.InputRequired("message")

在更新到最新版本的Flask WTF时，也可以在视图中使用validate_on_submit()（as recommended here）。

And the convenience validate_on_submit will check if it is a POST request and if it is valid.