我正在尝试使用 wtforms 在烧瓶中创建下拉列表，但由于某种原因我的表单无法验证，有人可以告诉我为什么吗？

Question

列表看起来就像我想要的那样，有所有正确的选项，但是当我点击提交（'Add Movement'）按钮时，它没有得到验证（它没有进入if form.validate_on_submit() 代码块）。它曾经在我添加 SelectField 之前得到验证，所以我倾向于认为我在那里做错了什么。

@app.route('/movements', methods=['GET','POST'])
def movements():
    form = MovementForm()
    if form.validate_on_submit():
        product = Product.query.filter_by(id=form.product.data).first()
        from_location = Location.query.filter_by(id=form.from_location.data).first()
        to_location = Location.query.filter_by(id=form.to_location.data).first()
        m = Movement(product = product.name, from_location = from_location.name, to_location = to_location.name, quantity = form.quantity.data)
        db.session.add(m)
        db.session.commit()
        movements = Movement.query.all()
        products = Product.query.all()
        locations = Location.query.all()
        return render_template('movements.html', movements=movements, products=products, locations=locations, form=form)
    
    form.product.choices = [(product.id,product.name) for product in Product.query.all()]
    form.from_location.choices = [(location.id,location.name) for location in Location.query.all()]
    form.to_location.choices = [(location.id,location.name) for location in Location.query.all()]
    movements = Movement.query.all()
    products = Product.query.all()
    locations = Location.query.all()
    return render_template('movements.html', movements=movements, products=products, locations=locations, form=form)

这是我的运动模型table:

class Movement(db.Model):
    id = db.Column(db.Integer, primary_key=True)
    product_id = db.Column(db.Integer, db.ForeignKey('product.id'))
    product = db.Column(db.String(50), nullable=False)
    from_location_id = db.Column(db.Integer, db.ForeignKey('location.id'))
    from_location = db.Column(db.String(50))
    to_location_id = db.Column(db.Integer, db.ForeignKey('location.id'))
    to_location = db.Column(db.String(50))
    quantity = db.Column(db.Integer, nullable=False)
    timestamp = db.Column(db.DateTime, nullable=False, default=datetime.utcnow)

这是表格：

class MovementForm(FlaskForm):
    product = SelectField("Product", choices = [])
    from_location = SelectField("From Location", choices = [])
    to_location = SelectField("To Location", choices = [])
    quantity = StringField("Quantity", validators=[DataRequired()])
    add_movement = SubmitField("Add Movement")

Answer 1

我想我也有类似的经历，问题是表单没有针对空的选择列表进行验证。因此，在验证之前填充 form.from_location.choices（和其他）可能会解决它：

@app.route('/movements', methods=['GET','POST'])
def movements():
    form = MovementForm()
    form.product.choices = [(product.id,product.name) for product in Product.query.all()]
    form.from_location.choices = [(location.id,location.name) for location in Location.query.all()]
    form.to_location.choices = [(location.id,location.name) for location in Location.query.all()]
    if form.validate_on_submit():
        # your code
        
    # your code
    return render_template('movements.html', movements=movements, products=products, locations=locations, form=form)

我正在尝试使用 wtforms 在烧瓶中创建下拉列表，但由于某种原因我的表单无法验证，有人可以告诉我为什么吗？

I'm trying to create drop down lists in flask using wtforms but my form won't validate for some reason, can someone tell me why?

python

flask

wtforms

flask-sqlalchemy

flask-wtforms