如何修复 Flask 中的“请求的 URL 不允许使用该方法”

Question

I am trying to redirect an authenticated user to a new template file but i keep getting this "The method is not allowed for the requested URL" error each time.

This my login Wtform model:

class Register(FlaskForm):
      username = StringField('Username',validators=[DataRequired(),
                    Length(min=2, max=20)],)
      email = StringField('Email',validators=[DataRequired(),Email()])

      password = PasswordField('Password', validators=[DataRequired()])
      confirm_password = PasswordField('Confirm Password', validators=[DataRequired(), EqualTo('password')])
      submit = SubmitField('Sign Up')

      def validate_email(self,data_field):
              if User.query.filter_by(email =data_field.data).first():
            raise ValidationError('There is an account with that email')

      def validate_username(self,data_field):
      if User.query.filter_by(username = data_field.data).first():
        raise ValidationError('That username is taken')

class Login(FlaskForm):
      email = StringField('Email',validators=[DataRequired(),Email()])

      password = PasswordField('Password', validators=[DataRequired()])
      remember = BooleanField('Remember Me')
      submit = SubmitField('Login')

This is the macro i used to render the form fields to use them with material design bootstrap.

 {% macro render_field(field, label_visible=true) %} {{ field(class_='form-control validate' , **kwargs) }} {% if field.errors %} {% for e in field.errors %} <p class="help-block">{{ e }}</p> {% endfor %} {% else %} {% if field.type != 'HiddenField' and label_visible %} <label for="{{ field.id }}" data-error="wrong" data-success="right">{{ field.label }}</label> {% endif %} {% endif %} {% endmacro %}

Here are the view functions for my routes.

@app.route("/")
@app.route("/home",methods=['GET','POST'])
def home():
    registerForm = Register()
    form = Login()
    if current_user.is_authenticated:
        return redirect(url_for('circles'))
    if registerForm.validate_on_submit():
        hashed_password = bcrypt.generate_password_hash(form.password.data).decode('utf-8')
        user = User(username = form.username.data, email = form.email.data, password = hashed_password)
        db.session.add(user)
        db.session.commit()
        flash(f'Your account has been created! You are now able to login!','success')
        return redirect(url_for('home'))

    if form.validate_on_submit():
        user = User.query.filter_by(email=form.email.data).first()
    if user and bcrypt.check_password_hash(user.password,form.password.data):
        login_user(user, remember=form.remember.data)
        next_page = request.args.get('next')
        return redirect(next_page) if next_page else redirect(url_for('circles'))

    else:
        flash('Login Unsuccessful. Please check email and password','danger')
#form=form, registerForm=registerForm

return render_template('home.html', title='login',form=form )


@app.route("/circle",methods=['GET','POST'])
def circles():
    return render_template('circle.html')

Here is how i implemented the modal for login.

 <div class="modal fade" id="modalLoginForm" tabindex="-1" role="dialog" aria-labelledby="myModalLabel" aria-hidden="true"> <div class="modal-dialog" role="document"> <div class="modal-content"> <div class="modal-header text-center"> <h4 class="modal-title w-100 font-weight-bold">Sign in</h4> <button type="button" class="close" data-dismiss="modal" aria-label="Close"> <span aria-hidden="true">&times;</span> </button> </div> <form method="POST" action=""> {{ form.hidden_tag() }} {% with messages = get_flashed_messages(with_categories=true) %} {% if messages %} {% for category,message in messages%} <div class="alert alert-{{ category }}"> {{message}} </div> {% endfor %} {% endif %} {% endwith %} <div class="modal-body mx-3"> <div class="md-form mb-5"> <i class="fas fa-envelope prefix grey-text"></i> {{ macros.render_field(form.email, label_visible=false, placeholder='Email', type='email') }} </div> <div class="md-form mb-4"> <i class="fas fa-lock prefix grey-text"></i> {{ macros.render_field(form.password, label_visible=false, placeholder='Password', type='password') }} <p class="font-small blue-text d-flex justify-content-end">Forgot <a href="#" class="blue-text ml-1"> Password?</a></p> </div> </div> <div class="modal-footer d-flex justify-content-center"> <!-- {{ form.submit(class="btn blue-gradient btn-block btn-rounded z-depth-1a") }} --> <button type="submit">submit</button> </div> </form> </div> </div> </div>

When i try submitting, it pops the error, if i give the form an action to the circles page it does not authenticate it just redirects to the page.If i separate the home view into two different view functions ie. login and register, and give them each their own template, it works fine. when i move them back to my home view so as to access both modals on my navbar with modals it fails to authenticate. Could anyone please give insight to where i maybe messing up. I'm a newbie in Flask.

Answer 1

With the tag <form method="POST" action=""> , your form would be submitted to the current url, so / . But only the /home endpoint supports a POST method. You should either change the decorator to @app.route("/",methods=['GET','POST']) , or change form tag to action="/home" .