python之将变量传递给 Flask WTForm

我想使用从路由传入的默认值来查询选择字段。我不知道如何将变量从 View 传递到 Form 类

class transactionsForm(Form): 
 
loan_id = QuerySelectField('trans_id', validators=[Required()], get_label='name', 
                           query_factory=lambda: trans.query.filter_by(trans_id=[MY VARIABLE]).all()) 

请您参考如下方法:

这是来自 QuerySelectField文档:

The query property on the field can be set from within a view to assign a query per-instance to the field. If the property is not set, the query_factory callable passed to the field constructor will be called to obtain a query.

这意味着您使用查询定义表单:

class transactionsForm(Form): 
    loan_id = QuerySelectField('trans_id', validators=[Required()], get_label='name') 

然后在你的 View 函数中，一旦你有一个实例，你就分配查询:

def viewFunction(my_variable): 
    form = transactionsForm() 
    my_query = trans.query.filter_by(trans_id=my_variable) 
    form.loan_id.query = my_query 
    if form.validate_on_submit(): 
        # ...