UndefinedError：使用wtforms和flask时，'form'未定义

时间：2018-02-22 11:30:41

标签： python forms flask jinja2 wtforms

每当我尝试运行我的代码时，我都会继续生成此错误，我查看了wtforms文档，但我找不到任何内容。这是我第一次使用wtforms和jinja2，所以我不知道是否错误地声明了什么。 这是我的app.py 

from flask import Flask, render_template, redirect, url_for, flash, request
from flask_sqlalchemy import SQLAlchemy
from flask_bootstrap import Bootstrap
from wtforms import StringField, PasswordField, BooleanField
from flask_wtf import FlaskForm
from wtforms.validators import InputRequired

app = Flask(__name__)
app.config['SECRET_KEY'] = 'Thisissupposedtobesecret!'
app.config['SQLALCHEMY_DATABASE_URI'] = "sqlite:////Users/app/app.db"
app.debug = True
bootstrap = Bootstrap(app)
db = SQLAlchemy(app)

relationship = db.Table('relationship',
                    db.Column('blog_id', db.Integer, db.ForeignKey('blogs.id')),
                    db.Column('tag_id', db.Integer, db.ForeignKey('tags.id')))


class User(db.Model):
    __tablename__ = 'users'
    id = db.Column(db.Integer, primary_key=True)
    username = db.Column(db.String(80), unique=True, nullable=False)
    email = db.Column(db.String(225), unique=True, nullable=False)
    password = db.Column(db.String(225), nullable=False)
    blogs = db.relationship('Blog', backref=db.backref('author'), lazy='dynamic')

    def __init__(self, username, email, password):
        self.username = username
        self.email = email
        self.password = password

    def __repr__(self):
        return '<User %r>' % self.username


class Blog(db.Model):
    __tablename__ = 'blogs'
    id = db.Column(db.Integer, primary_key=True)
    user_id = db.Column(db.Integer, db.ForeignKey('users.id'))
    blogname = db.Column(db.Integer, unique=True, nullable=False)
    body = db.Column(db.String(600), nullable=False)
    tags = db.relationship('Tags', secondary=relationship,
                       backref=db.backref('tagged'), lazy='dynamic')

    def __init__(self, blogname, body):
        self.blogname = blogname
        self.body = body

    def __repr__(self):
        return '<Info %r>' % self.blogname


class Tags(db.Model):
    __tablename__ = 'tags'
    id = db.Column(db.Integer, primary_key=True)
    tagname = db.Column(db.String(80), unique=True)

    def __init__(self, tagname):
        self.tagname = tagname

    def __repr__(self):
        return '<Tags %r>' % self.tagname


class LoginForm(FlaskForm):
    username = StringField('username', validators=[InputRequired()])
    password = PasswordField('password', validators=[InputRequired()])
    remember = BooleanField('remember me')


class SignupForm(FlaskForm):
    email = StringField('email', validators=[InputRequired()])
    username = StringField('username', validators=[InputRequired()])
    password = PasswordField('password', validators=[InputRequired()])


# this will be the home page
@app.route('/')
def index():
    return render_template('dashboard.html')


@app.route('/signup', methods=['POST'])
def signup():
    form = SignupForm(request.form)
    if request.method == 'POST':
        if form.validate_on_submit():
            user = User(username=form.username.data, email=form.email.data, password=form.password.data)
            db.session.add(user)
            db.session.commit()

    return render_template('dashboard.html', form=form)

这是我的html代码，使用jinja2，在这里我希望用户能够在线添加帐户，然后将该帐户提交到数据库

 {% import "wtf.html" as wtf %}
 {% block title %}
    Sign up
 {% endblock %}

 {% block styles %}
      <link rel="stylesheet" type="text/css" href="{{ url_for('static', filename='style.css') }}">
 {% endblock %}

  {% block content %}
  <div class="form">
        <div id="signup">
             <h1>Sign Up for Free</h1>
        <form method="POST" action=“{{ url_for('signup')}}”>{{ csrf_input }}
            <div class="top-row">
                <div class="field-wrap">
                {{wtf.form_field(form.username)}}
            </div>
                <div class="field-wrap">
                {{wtf.form_field(form.email)}}
             </div>
                <div class="field-wrap">
                {{wtf.form_field(form.password)}}
                </div>
            </div>
            <input type="submit"/>
        </form>
        </div>
 </div>
{% endblock %}

我的追溯错误是

UndefinedError: 'form' is undefined
File "/Users/amy.faulkner/app/venv/lib/python2.7/site-packages/flask/app.py", line 1997, in __call__
   return self.wsgi_app(environ, start_response)
File "/Users/amy.faulkner/app/venv/lib/python2.7/site-packages/flask/app.py", line 1985, in wsgi_app
    response = self.handle_exception(e)
File "/Users/amy.faulkner/app/venv/lib/python2.7/site-packages/flask/app.py", line 1540, in handle_exception
    reraise(exc_type, exc_value, tb)
File "/Users/amy.faulkner/app/venv/lib/python2.7/site-packages/flask/app.py", line 1982, in wsgi_app
    response = self.full_dispatch_request()
File "/Users/amy.faulkner/app/venv/lib/python2.7/site-packages/flask/app.py", line 1614, in full_dispatch_request
    rv = self.handle_user_exception(e)
File "/Users/amy.faulkner/app/venv/lib/python2.7/site-packages/flask/app.py", line 1517, in handle_user_exception
    reraise(exc_type, exc_value, tb)
File "/Users/amy.faulkner/app/venv/lib/python2.7/site-packages/flask/app.py", line 1612, in full_dispatch_request
    rv = self.dispatch_request()
File "/Users/amy.faulkner/app/venv/lib/python2.7/site-packages/flask/app.py", line 1598, in dispatch_request
    return self.view_functions[rule.endpoint](**req.view_args)
File "/Users/amy.faulkner/app/app.py", line 82, in index
    return render_template('dashboard.html')
File "/Users/amy.faulkner/app/venv/lib/python2.7/site-packages/flask/templating.py", line 134, in render_template
     context, ctx.app)
File "/Users/amy.faulkner/app/venv/lib/python2.7/site-packages/flask/templating.py", line 116, in _render
     rv = template.render(context)
File "/Users/amy.faulkner/app/venv/lib/python2.7/site-packages/jinja2/environment.py", line 1008, in render
      return self.environment.handle_exception(exc_info, True)
File "/Users/amy.faulkner/app/venv/lib/python2.7/site-packages/jinja2/environment.py", line 780, in handle_exception
      reraise(exc_type, exc_value, tb)
File "/Users/amy.faulkner/app/templates/dashboard.html", line 11, in top-level template code
     {% block content %}
File "/Users/amy.faulkner/app/templates/dashboard.html", line 18, in block "content"
     {{wtf.form_field(form.username)}}
File "/Users/amy.faulkner/app/venv/lib/python2.7/site-packages/jinja2/environment.py", line 430, in getattr
     return getattr(obj, attribute)

1 个答案:

答案 0 :(得分：1)

你可以试试这个。 在utils.html中创建render_field 

{% macro render_field(field) %}
  <dt>{{ field.label }}
  <dd>{{ field(**kwargs)|safe }}
  {% if field.errors %}
    <ul class=errors>
    {% for error in field.errors %}
      <li>{{ error }}</li>
    {% endfor %}
    </ul>
  {% endif %}
  </dd>
{% endmacro %}

并在模板中导入此文件

{% from "utils.html" import render_field %}
<form method=post action="{{ url_for('signup')}}">
<div>
    {{ render_field(form.username) }}
    {{ render_field(form.email) }}
    {{ render_field(form.password) }}
</div>
<p><input type=submit value=Register>
</form>

请参阅this文章了解更多详情

您可以在＆＃34; wtf.html＆＃34;中查看您的wtf宏方法。此错误即将发生，因为此处未定义任何表单

相关问题
最新问题