Question

我从Flask开始就遇到了这个问题。我需要重定向到url。当我尝试使用此代码时，请运行良好：

@app.route('/fa')
def hello():
    return redirect(url_for('foo'))

@app.route('/foo')
def foo():
    return 'Hello Foo!'

但是现在，我需要这个，但有一个渲染模板。这是代码，但后来我，但用户，烧瓶重定向并给出此错误：方法不允许

from flask import Flask, render_template, redirect, url_for
from forms import MyForm

app = Flask(__name__)
app.config.from_object(__name__)
@app.route('/')
def home():
  return render_template('home.html')

@app.route('/about')
def about():
  return render_template('about.html')

@app.route("/signin", methods=("GET", "POST"))
def signin():
  form = MyForm()
  if request.method == 'POST':
    if form.validate() == True:
      return redirect(url_for('foo'))
  elif request.method == 'GET':
    return render_template("signin.html", form=form)


if __name__ == "__main__":
  app.debug = True
  app.run()

signin.html

{% block content %}
  <h2>Sign In</h2>

  <form method="POST" action="{{ url_for('signin') }}">

  {{ form.hidden_tag() }}

  {{ form.username.label }}
  {{ form.username(size=20) }}

  {{ form.password.label }}
  {{ form.password(size=20) }}

  {{ form.submit }}
  </form>

{% endblock %}

MyForm.py

from flask_wtf import Form, TextField, PasswordField, DataRequired, SubmitField

class MyForm(Form):
  username = TextField("Username", validators=[DataRequired()])
  password = PasswordField("Password", validators=[DataRequired()])
  submit = SubmitField("Sign In")

def validate(self):    
    user = "franco"
    if user == self.username:
        return True
    else:
        return False

错误：

 ValueError
 ValueError: View function did not return a response

为什么？感谢

Answer 1

问题不在于重定向（它工作正常），但在http方法是POST且表单无效的情况下。在这种情况下，signin函数没有有效的响应，因此错误。

@app.route("/signin", methods=("GET", "POST"))
def signin():
    form = MyForm()
    if request.method == 'POST':
        if form.validate() == True:
            return redirect(url_for('foo'))
        else:
            # If method is POST and form failed to validate
            # Do something (flash message?)
            return render_template("signin.html", form=form)

    elif request.method == 'GET':
        return render_template("signin.html", form=form)

Flask：不要重定向到Url

1 个答案: