如何在Play 2中指定复杂的表单验证？

Question

我理解如何在Play 2中添加简单的表单验证nonEmptyText,但是如何实现更复杂的验证,例如"必须至少定义一个字段"？现在我在我的模型对象中抛出异常,如果它被所有Nones 初始化,但这会产生一个讨厌的错误消息.我希望在表单页面上收到一条友好的错误消息.

Answer 1

您可以在表单定义中嵌套mappings/ tuples并verifying在映射,子映射,元组和子元组上添加规则.然后,在模板中,您可以使用form.errors("fieldname")特定字段或字段组检索错误.

例如 :

val signinForm: Form[Account] = Form(
    mapping(
        "name" -> text(minLength=6, maxLength=50),
        "email" -> email,
        "password" -> tuple(
            "main" -> text(minLength=8, maxLength=16),
            "confirm" -> text
        ).verifying(
            // Add an additional constraint: both passwords must match
            "Passwords don't match", password => password._1 == password._2
        )
    )(Account.apply)(Account.unapply)
)

如果您有两个不同的密码,则可以使用以下方法检索模板中的错误 form.errors("password")

在这个例子中,你必须自己编写Account.apply并Account.unapply处理(String, String, (String, String))

Answer 2

我已经改进了@ kheraud接受的答案.您可以将元组转换回单个字符串.这允许您使用默认的apply/unapply函数.

示例:

val signinForm: Form[Account] = Form(
    mapping(
        "name" -> text(minLength=6, maxLength=50),
        "email" -> email,
        "password" -> tuple(
            "main" -> text(minLength=8, maxLength=16),
            "confirm" -> text
        ).verifying(
            // Add an additional constraint: both passwords must match
            "Passwords don't match", password => password._1 == password._2
        ).transform(
            { case (main, confirm) => main },
            (main: String) => ("", "")
        )
    )(Account.apply)(Account.unapply)
)