Flask wtf 表单不验证自定义验证器

Question

所以我在一个 html 页面上有一个登录表单和注册表单。我有用于注册表单的自定义验证器不起作用。 routes.py 看起来像这样

@app.route("/", methods=['GET', 'POST'])
def home():
    login_form = LoginForm(request.form, prefix="login-form")
    regis_form = RegistrationForm(request.form, prefix="register-form")
    return render_template('home.html', login_form=login_form, regis_form=regis_form)


@app.route("/register", methods=['POST'])
def register():
    regis_form  = RegistrationForm(request.form, prefix='register-form')
    if regis_form.validate_on_submit():
        hashed_password = bcrypt.generate_password_hash(regis_form.password_regis.data).decode('utf-8')
        user = User(username=regis_form.username_regis.data, email=regis_form.email_regis.data, password=hashed_password)
        db.session.add(user)
        db.session.commit()
        flash('Your account has been created! You are now able to log in', 'success')
        return redirect(url_for('home'))
    return redirect(url_for('home'))

@app.route("/login", methods=['POST'])
def login():
    login_form = LoginForm(request.form, prefix='login-form')
    if login_form.validate_on_submit():
        user = User.query.filter_by(email=login_form.email_login.data).first()
        if user and bcrypt.check_password_hash(user.password, login_form.password_login.data):
            login_user(user, remember=login_form.remember.data)
            next_page = request.args.get('next')
            return redirect(next_page) if next_page else redirect(url_for('home'))
        else:
            flash('Login Unsuccessful. Please check email and password', 'danger')
    return redirect(url_for('home'))

forms.py

class RegistrationForm(FlaskForm):
    username_regis = StringField('Username',
                           validators=[DataRequired(), Length(min=5, max=20)])
    email_regis = EmailField('Email',
                        validators=[DataRequired(), Email()])
    password_regis = PasswordField('Password', validators=[DataRequired()])
    submit_regis = SubmitField('Sign Up')

    def validate_username_regis(self, username_regis):
        user = User.query.filter_by(username=username_regis.data).first()
        if user:
            raise ValidationError('That username is taken. Please choose a different one.')

    def validate_email_regis(self, email_regis):
        user = User.query.filter_by(email=email_regis.data).first()
        if user:
            raise ValidationError('That email is taken. Please choose a different one.')



class LoginForm(FlaskForm):
    email_login = EmailField('Email',
                        validators=[DataRequired(), Email()])
    password_login = PasswordField('Password', validators=[DataRequired()])
    remember = BooleanField('Remember Me')
    submit_login = SubmitField('Login')

home.html

<div>
  <form method="POST" action="{{ url_for('login') }}">
      {{ login_form.hidden_tag() }}
      <fieldset class="form-group">
          <div class="form-group">
              {% if login_form.email_login.errors %}
                  {{ login_form.email_login(class="form-control is-invalid") }}
                  <div class="invalid-feedback">
                      {% for error in login_form.email_login.errors %}
                          <span>{{ error }}</span>
                      {% endfor %}
                  </div>
              {% else %}
                  {{ login_form.email_login(class="form-control mb-2", placeholder="Email") }}
              {% endif %}
          </div>
          <div class="form-group">
              {% if login_form.password_login.errors %}
                  {{ login_form.password_login(class="form-control is-invalid") }}
                  <div class="invalid-feedback">
                      {% for error in login_form.password_login.errors %}
                          <span>{{ error }}</span>
                      {% endfor %}
                  </div>
              {% else %}
                  {{ login_form.password_login(class="form-control mb-2", placeholder="Password") }}
              {% endif %}
          </div>
      </fieldset>
      <div class="form-group">
          {{ login_form.submit_login(class="btn btn-danger") }}
      </div>
  </form>
</div>
<div class="" id="regis">
  <form method="POST" action="{{ url_for('register') }}">
      {{ regis_form.hidden_tag() }}
      <fieldset class="form-group">
          <div class="form-group">
              {% if regis_form.username_regis.errors %}
                  {{ regis_form.username_regis(class="form-control form-control-md is-invalid") }}
                  <div class="invalid-feedback">
                      {% for error in regis_form.username_regis.errors %}
                          <span>{{ error }}</span>
                      {% endfor %}
                  </div>
              {% else %}
                  {{ regis_form.username_regis(class="form-control form-control-md mb-2", placeholder="Username") }}
              {% endif %}
          </div>
          <div class="form-group">
              {% if regis_form.email_regis.errors %}
                  {{ regis_form.email_regis(class="form-control form-control-md is-invalid") }}
                  <div class="invalid-feedback">
                      {% for error in regis_form.email_regis.errors %}
                          <span>{{ error }}</span>
                      {% endfor %}
                  </div>
              {% else %}
                  {{ regis_form.email_regis(class="form-control form-control-md mb-2", placeholder="Email") }}
              {% endif %}
          </div>
          <div class="form-group">
              {% if regis_form.password_regis.errors %}
                  {{ regis_form.password_regis(class="form-control form-control-md is-invalid") }}
                  <div class="invalid-feedback">
                      {% for error in regis_form.password_regis.errors %}
                          <span>{{ error }}</span>
                      {% endfor %}
                  </div>
              {% else %}
                  {{ regis_form.password_regis(class="form-control form-control-md mb-2", placeholder="Password") }}
              {% endif %}
          </div>
      </fieldset>
      <div class="form-group">
          {{ regis_form.submit_regis(class="btn btn-danger") }}
      </div>
  </form>
</div>

以前我在同一个 home 路由上都有两个表单，自定义验证器正在工作，但是如果我故意提交 register 表单有错误，那么登录表单也会显示错误，例如需要输入。所以为了解决这个问题，我这样做了，但现在注册表单没有验证自定义验证器

Answer 1

在您的数据验证失败后，您执行return redirect(url_for('home'))。这导致在主路由上出现GET。这会填充表单的一个新实例：regis_form = RegistrationForm(request.form, prefix="register-form")。您的错误信息将丢失，它位于不同的实例上。

要获取错误信息，您的register() 路由需要使用render_template('home.html', login_form=login_form, regis_form=regis_form) 模板render，而不是重定向。不要忘记创建LoginForm 的新实例，否则渲染会失败。