Question

我正在研究this Scala Play application并且在研究和思考之后有点结束了一种设计，它将所有表单放在一个表单包下面，在它们在视图中使用的级别（或最顶层）适用）例如

 app
    | views 
           | account
                    | form (all Form used by account will be here)
                          | PasswordChangeForm.scala

然后PasswordChangeForm.scala表单实现为：

package views.account.form

import play.api.data.Form
import play.api.data.Forms.{mapping, text}
import play.api.i18n.Messages

case class PasswordChange(password: String, repeatPassword: String)

object PasswordChangeForm {
  val Instance = Form {
    mapping(
      "password" -> text(minLength = 5),
      "repeatPassword" -> text(minLength = 5)
    )(PasswordChange.apply)(PasswordChange.unapply).
      verifying(Messages("playauthenticate.change_password.error.passwords_not_same"),
        data => data.password != null && !data.password.isEmpty && data.password.equals(data.repeatPassword))
  }
}

问题是我不知道如何使Messages或更好MessagesApi可用于错误报告的表单。

编译器错误符合预期could not find implicit value for parameter messages: play.api.i18n.Messages：

[error] /home/bravegag/code/play-authenticate-usage-scala/app/views/account/form/PasswordChangeForm.scala:15: could not find implicit value for parameter messages: play.api.i18n.Messages
[error]       verifying(Messages("playauthenticate.change_password.error.passwords_not_same"),

更新有可能重构以上解决方案：

val Instance = Form {

到

def create(implicit messages: Messages) = Form {

但是每次都会创建Form的新实例。

Answer 1

使用guice依赖注入使Sub IDgen() Dim ID, Yr, Dt, Mth, Hr, Min As Integer ID = Environ("username") Yr = Right(Year(Date), 2) Mth = Format(Month(Date), "#00") Dt = Format(Day(Date), "#00") Hr = Format(Hour(Time), "#00") Min = Format(Minute(Time), "#00") Sheets("Sheet1").Range("A2").Value = "C" & Yr & Mth & Dt & "." & Hr & Min & "." & ID End Sub成为单例类并注入PasswordChangeForm。

MessagesApi

用法：

@Singleton
class PasswordChangeForm @Inject() (messages: MessagesApi) {
  //now use it like this messages("somekey")
}

上述结构是单身，由guice确保。 Guice在messages("somekey")初始化期间注入消息api。

Scala Play 2.5表单约定和隐式消息（MessagesApi）访问

1 个答案: