尽管有 csrf 令牌，但表单未验证

Question

我在这里看到了一些类似的问题，但似乎没有一个解决方案在这里适用（问题通常是它缺少 csrf 令牌，这里不是这种情况）。

我有一个包含四个字段的表单- 3 个带有 SelectField 的下拉列表和一个 StringField- 使用烧瓶 wtforms 构建。我尝试向它添加一个编辑功能，它使用相同的 HTML 模板，但是它没有得到验证（没有进入 form.validate_on_submit 部分）。这是函数的代码：

@app.route('/movements/<int:movement_id>/edit', methods=['GET', 'POST'])   
def edit_movement(movement_id):
    movement = Movement.query.get_or_404(movement_id)
    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()
        if int((Balance.query.filter_by(product = product.name).filter_by(location = from_location.name).first()).balance) < int(form.quantity.data) and from_location.name != "":
           flash("Invalid movement. Quantity of the product is insufficient.")
        else: 
            movement.product_id = product.id
            movement.product = product.name
            movement.from_location_id = from_location.id
            movement.from_location = from_location.name
            movement.to_location_id = to_location.id
            movement.to_location = to_location.name
            movement.quantity = form.quantity.data
            db.session.commit()
            flash('The product movement has been edited!', 'success')
        return redirect(url_for('movements'))
    elif request.method == 'GET':
        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()]
        form.quantity.data = movement.quantity
    edit_button = True   
    return render_template('movements.html',form=form, edit_button=edit_button)

这是表单的代码：

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

这是桌子的模型：

class Movement(db.Model):
    id = db.Column(db.Integer, primary_key=True)
    product_id = db.Column(db.Integer, db.ForeignKey('product.id'), nullable=False)
    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)

表单的 HTML 代码：

<form action="" method="POST">
        {{ form.csrf_token }}
        {{ form.product.label }}
        {{ form.product }}
        {{ form.from_location.label }}
        {{ form.from_location }}
        {{ form.to_location.label }}
        {{ form.to_location }}
        {{ form.quantity.label }}
        {{ form.quantity }}
        {% if edit_button %}
            <input type="submit" value="Edit Movement">
        {% else %}
            {{ form.add_movement }}
        {% endif %}
</form>

Answer 1

validate_on_submit 是一个方便的函数，它结合了对表单是否已提交的检查（即 POST、PUT、PATCH 或 DELETE）与对 form.validate 的调用。如果验证失败，form.errors 持有的字典将填充有用的信息。

如果validate_on_submit 返回 False，则调试问题的一个有用步骤是记录（打印）form.errors 的内容。

Answer 2

你代码中的form.errors如下：

{'product': ['Not a valid choice'], 'from_location': ['Not a valid choice'], 'to_location': ['Not a valid choice']}

所以validate_on_submit返回False是合理的。

如果您注释掉这些字段并只留下它应该有效的数量。以下更改对我有用，我设法更新了数据库中的数量。如果它也适用于您，那么您可以尝试取消注释每个字段并进一步调试。

将表格更改为：

class MovementForm(FlaskForm):
quantity = StringField("Quantity", validators=[DataRequired()])
add_movement = SubmitField("Add Movement")

以及去往的路线：

@app.route('/movements/<int:movement_id>/edit', methods=['GET', 'POST'])
def edit_movement(movement_id):
movement = Movement.query.get_or_404(movement_id)
form = MovementForm()
if form.validate_on_submit():
    movement.quantity = form.quantity.data
    db.session.commit()
    flash('The product movement has been edited!', 'success')
    return redirect(url_for('movements'))
elif request.method == 'GET':
    form.quantity.data = movement.quantity
print(form.errors)
edit_button = True
return render_template('movements.html', form=form, edit_button=edit_button)

将模板更改为：

<form action="" method="POST">
    {{ form.csrf_token }}
    {{ form.quantity.label }}
    {{ form.quantity }}
    {% if edit_button %}
        <input type="submit" value="Edit Movement">
    {% else %}
        {{ form.add_movement }}
    {% endif %}
</form>

更新：

您面临的问题描述为here。

请尝试以下操作，如果它按预期工作，然后类似地设置其余字段（它对我有用，我设法更新了数据库中的数量和 from_location/id）：

形式：

class MovementForm(FlaskForm):
fromloc = [(location.id,location.name) for location in Location.query.all()]
from_location_id = SelectField("From Location ID", choices = fromloc, coerce=int)
quantity = StringField("Quantity", validators=[DataRequired()])
add_movement = SubmitField("Add Movement")

路线：

@app.route('/movements/<int:movement_id>/edit', methods=['GET', 'POST'])
def edit_movement(movement_id):
    movement = Movement.query.get_or_404(movement_id)
    form = MovementForm()
    if form.validate_on_submit():
        movement.from_location_id = form.from_location_id.data
        movement.from_location = (Location.query.filter_by(id = form.from_location_id.data).first()).name
        movement.quantity = form.quantity.data
        db.session.commit()
        flash('The product movement has been edited!', 'success')
        return redirect(url_for('movements'))
    elif request.method == 'GET':
        form.from_location_id.choices = [(location.id,location.name) for location in Location.query.all()]
        form.quantity.data = movement.quantity
    print(form.errors)
    edit_button = True
    return render_template('movements.html', form=form, edit_button=edit_button)

模板：

<form action="" method="POST">
    {{ form.csrf_token }}
    {{ form.from_location_id.label }}
    {{ form.from_location_id }}
    {{ form.quantity.label }}
    {{ form.quantity }}
    {% if edit_button %}
        <input type="submit" value="Edit Movement">
    {% else %}
        {{ form.add_movement }}
    {% endif %}
</form>

Answer 3

我仍然不太清楚为什么我的表单没有验证，但是在我将 if form.validate_on_submit() 替换为 if request.method == 'POST' 后，我的函数开始工作了。