Question

我想从下拉菜单中选择一个选项。

class GuestForm(Form):
    name = StringField('Full Name', [validators.length(min=1, max=50)])
    phone = StringField('Phone')
    adults = StringField('Adults')
    status = SelectField('Status', choices=[('BK', 'Booked'), ('CK', 'Cancelled')])

路线

@app.route('/edit_guest/<string:id>', methods=['GET', 'POST'])
def edit_guest(id):
    # Create cursor
    cur = mysql.connection.cursor()
    # Get guest by id
    result = cur.execute("SELECT * FROM guests WHERE id = %s", [id])
    guest = cur.fetchone()
    # Get form
    form = GuestForm(request.form)

    # Populate Guest form fields
    form.name.data = guest['name']
    form.phone.data = guest['phone']
    form.adults.data = guest['adults']
    form.status.data = guest['status']

    if request.method == 'POST' and form.validate():
        name = request.form['name']
        phone = request.form['phone']
        adults = request.form['adults']
        status = request.form['status']

Jinja2模板

<form method="POST" action="">
    <table style="width:100%">
        <tr>
            <td>{{render_field(form.name, class_="form-control")}}</td>
            <td>{{render_field(form.phone, class_="form-control")}}</td>
            <td>{{render_field(form.adults, class_="form-control")}}</td>
            <td>{{render_field(form.status, class_="form-control")}}</td>
        <tr>
    </table>
</form>

当我在选择了值之后提交时，它在下拉值下面显示“不是有效的选择”。

Answer 1

您的问题很难理解。对于尚未看到您的代码的人，很难组合代码片段。有很多很好的教程，可以使您对Flask Forms有很好的了解。我认为您应该在此花些时间以获得更好的理解。

尽管如此，我试图为您提供一个最小的运行示例。该示例创建一个您可以提交的表单。对于您的下一个问题，请尝试自己提出一个最小的例子。

dropdown.py

from flask import Flask
from flask import render_template_string, redirect, url_for
from flask_wtf import FlaskForm
from wtforms.fields import *
from wtforms.validators import *


class GuestForm(FlaskForm):
    name = StringField('Full Name', [Length(min=1, max=50)])
    phone = StringField('Phone')
    adults = StringField('Adults')
    status = SelectField('Status', choices=[('BK', 'Booked'), ('CK', 'Cancelled')])


app = Flask(__name__)
app.config['WTF_CSRF_ENABLED'] = False

@app.route('/edit_guest/<string:id>', methods=['GET', 'POST'])
def edit_guest(id):

    # Instead of hard coding, read data from database based on id
    # result = cur.execute("SELECT * FROM guests WHERE id = %s", [id])
    # guests ...
    guests = {'name': 'John', 'phone': '123456', 'adults': 2, 'status': 'BK'}

    form = GuestForm(data=guests)

    if form.validate_on_submit():

        # Update data in database
        # "UPDATE guests SET ... WHERE id = id
        # access new data with **form.data
        guests = form.data

        return redirect(url_for("edit_guest", id="Test-id"))

    return render_template_string(
    """
    <html>
        <head></head>
        <body>
            <form method="POST" action="">
                <table style="width:100%">
                    <tbody>
                        {% for field in form %}
                            <tr>
                                <td>{{ field.label() }} </td>
                                <td>{{ field() }} </td>
                            </tr>
                        {% endfor %}
                        <tr>
                            <td></td>
                            <td><input type='submit'></td>
                        </tr>
                    </tbody>
                </table>
            </form>
        </body>
    </html>
    """, form=form)


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

在Python Flask中选择下拉值

1 个答案: