Question

我在表单上定义自定义Constraint时遇到问题。这是我的表格：

val form = Form(
  mapping(
    "field" -> boolean
)(MyForm.apply)(MyForm.unapply)

如果我执行以下操作：

val form = Form(
  mapping(
    "field" -> boolean
)(MyForm.apply)(MyForm.unapply).verifying("my constraint", f => f.field == true)

然后正常工作。但是，如果尝试使用以下自定义定义的Constraint，则会引发空指针异常，并且我不知道为什么：

val form = Form(
  mapping(
    "field" -> boolean
)(MyForm.apply)(MyForm.unapply).verifying(myconstraint)

val myconstraint : Constraint[MyForm] = Constraint("myconstraint")({
   form => 
      if(form.field == true){
          Valid
      }else {
        Invalid(Seq(ValidationError("problem")))
      }
})

我尝试使用println进行调试，但控制台上没有任何内容。

Answer 1

尝试像这样将SELECT u.[FirstName] + ' ' + u.[LastName] AS EmployeeName, CONVERT(DATE, e.loggedTime) as theday, min(e.LoggedTime) as first max(e.LoggedTime) as last FROM [ProtegeGX].[dbo].[Users] u JOIN [ProtegeGXEvents].[dbo].[Events] e ON e.RecordIndex1 = u.UserID JOIN [ProtegeGX].[dbo].[EventTypes] et on e.EventTypeID = et.EventTypeID WHERE e.LoggedTime Between '2019-05-29' AND '2019-05-31' AND u.userid = 97 GROUP BY u.[FirstName] + ' ' + u.[LastName], CONVERT(DATE, e.loggedTime);定义移到myconstraint定义之上

form

由于可能存在的前向引用问题，我们最终引用了一个未初始化的值。

自定义定义的表单约束引发空指针异常

1 个答案: