project / app / froms.py

Question

无法将WTForm字段的实例变量作为实例变量

这将具有多个（灵活的）字段，可以将其级联以增加字段的数量。

该程序对于一个简单的类，一个登录字段和一个密码字段（如果该字段是类变量）正常工作。

project / app / froms.py

class LoginForm(FlaskForm):
    username = StringField('Username')
    password = PasswordField('Password')

如果在构造函数中初始化了字段，则程序无法正常工作。程序错误是

project / app / forms.py

class TestLoginForm(FlaskForm):
    def __init__(self):
        username = StringField('Username')
        password = PasswordField('Password')

以下是该程序的其他部分

<!-- project/app/templates/test.html -->
<!DOCTYPE html>
<html>
<head>
<title>Login Page</title>
</head>
<body>

    <h1>Sign In</h1>
    <form method="post" novalidate>
        {{ form.hidden_tag() }}
    <p>
        {{ form.username.label }}<br>
        {{ form.username(size=32) }}
    </p>
    <p>
        {{ form.password.label }}<br>
        {{ form.password(size=32) }}
    </p>
    <p>{{ form.submit() }}</p>
</form>

</body>
</html>

project / app / routes.py

from app import app
from flask import render_template
from app.forms import TestLoginForm

@app.route('/', methods=['GET','POST'])
@app.route('/login', methods=['GET','POST'])
def index():

    form = TestLoginForm()
    return render_template('test.html', form=form)

project / app / init .py

from flask import Flask

app = Flask(__name__)
app.config['SECRET_KEY'] = 'you-will-never-guess'

from app import routes

project / website.py

from app import app

请让我知道我需要学习哪些概念，并为获得问题结果的可能方法提供建议。

Traceback (most recent call last):
  File "C:\Users\css120807\AppData\Local\Continuum\anaconda3\lib\site-packages\flask\app.py", line 2309, in __call__
    return self.wsgi_app(environ, start_response)
  File "C:\Users\css120807\AppData\Local\Continuum\anaconda3\lib\site-packages\flask\app.py", line 2295, in wsgi_app
    response = self.handle_exception(e)
  File "C:\Users\css120807\AppData\Local\Continuum\anaconda3\lib\site-packages\flask\app.py", line 1741, in handle_exception
    reraise(exc_type, exc_value, tb)
  File "C:\Users\css120807\AppData\Local\Continuum\anaconda3\lib\site-packages\flask\_compat.py", line 35, in reraise
    raise value
  File "C:\Users\css120807\AppData\Local\Continuum\anaconda3\lib\site-packages\flask\app.py", line 2292, in wsgi_app
    response = self.full_dispatch_request()
  File "C:\Users\css120807\AppData\Local\Continuum\anaconda3\lib\site-packages\flask\app.py", line 1815, in full_dispatch_request
    rv = self.handle_user_exception(e)
  File "C:\Users\css120807\AppData\Local\Continuum\anaconda3\lib\site-packages\flask\app.py", line 1718, in handle_user_exception
    reraise(exc_type, exc_value, tb)
  File "C:\Users\css120807\AppData\Local\Continuum\anaconda3\lib\site-packages\flask\_compat.py", line 35, in reraise
    raise value
  File "C:\Users\css120807\AppData\Local\Continuum\anaconda3\lib\site-packages\flask\app.py", line 1813, in full_dispatch_request
    rv = self.dispatch_request()
  File "C:\Users\css120807\AppData\Local\Continuum\anaconda3\lib\site-packages\flask\app.py", line 1799, in dispatch_request
    return self.view_functions[rule.endpoint](**req.view_args)
  File "C:\Users\css120807\Documents\Flask_testWebsite\app\routes.py", line 13, in index
    return render_template('test.html', form=form)
  File "C:\Users\css120807\AppData\Local\Continuum\anaconda3\lib\site-packages\flask\templating.py", line 135, in render_template
    context, ctx.app)
  File "C:\Users\css120807\AppData\Local\Continuum\anaconda3\lib\site-packages\flask\templating.py", line 117, in _render
    rv = template.render(context)
  File "C:\Users\css120807\AppData\Local\Continuum\anaconda3\lib\site-packages\jinja2\asyncsupport.py", line 76, in render
    return original_render(self, *args, **kwargs)
  File "C:\Users\css120807\AppData\Local\Continuum\anaconda3\lib\site-packages\jinja2\environment.py", line 1008, in render
    return self.environment.handle_exception(exc_info, True)
  File "C:\Users\css120807\AppData\Local\Continuum\anaconda3\lib\site-packages\jinja2\environment.py", line 780, in handle_exception
    reraise(exc_type, exc_value, tb)
  File "C:\Users\css120807\AppData\Local\Continuum\anaconda3\lib\site-packages\jinja2\_compat.py", line 37, in reraise
    raise value.with_traceback(tb)
  File "C:\Users\css120807\Documents\Flask_testWebsite\app\templates\test.html", line 10, in top-level template code
    {{ form.hidden_tag() }}
  File "C:\Users\css120807\AppData\Local\Continuum\anaconda3\lib\site-packages\flask_wtf\form.py", line 135, in hidden_tag
    u'\n'.join(text_type(f) for f in hidden_fields(fields or self))
  File "C:\Users\css120807\AppData\Local\Continuum\anaconda3\lib\site-packages\flask_wtf\form.py", line 135, in <genexpr>
    u'\n'.join(text_type(f) for f in hidden_fields(fields or self))
  File "C:\Users\css120807\AppData\Local\Continuum\anaconda3\lib\site-packages\flask_wtf\form.py", line 125, in hidden_fields
    for f in fields:
  File "C:\Users\css120807\AppData\Local\Continuum\anaconda3\lib\site-packages\wtforms\form.py", line 57, in __iter__
    return iter(itervalues(self._fields))
AttributeError: 'TestLoginForm' object has no attribute '_fields'

Answer 1

在快速入门中，有一个创建表单的示例： https://flask-wtf.readthedocs.io/en/stable/quickstart.html#creating-forms

有类字段，而不是实例（在__init__中）。

如果我理解正确，那么您想从父类继承字段，为什么不这样：

class MyForm(FlaskForm):
    name = StringField('name', validators=[DataRequired()])

class AnotherForm(MyForm):
    surname = StringField('surname', validators=[DataRequired()])

然后您可以在route.py中使用两种形式：

form = MyForm()

带有csrf令牌和名称字段

或

form = AnotherForm()

包含MyForm（csrf +名称）和姓氏中的所有内容

在表单类中将表单字段作为实例变量初始化的问题

project / app / froms.py

project / app / forms.py

project / app / routes.py

project / app / init .py

project / website.py

1 个答案: