scala - 玩框架如何重用和扩展表单映射

Question

我有一个如下所示的表单映射:

val myBaseMapping =  mapping(
  "email"                -> email,
  "password"             -> text.verifying("Please provide a password", !_.isEmpty)
)(BaseModel.apply)(BaseModel.unapply)

这代表 FormA。我有另一种形式，FormB，它是相同的，但增加了几个字段。这是它的映射的样子:

val myExtendedMapping =  mapping(
  "email"                -> email,
  "password"             -> text.verifying("Please provide a password", !_.isEmpty)
  "name"                 -> text,
  "website"              -> text
)(ChildModel.apply)(ChildModel.unapply)

ChildModel 扩展了 BaseModel:它添加了 2 个新字段，name 和 website。

我正在尝试以不必为共享字段(电子邮件和密码)复制绑定(bind)定义的方式编写 myExtendedMapping 代码。

我不确定这里的 Scala 语法是什么。我不知道如何“扩展”给定的映射并向其添加绑定(bind)。另外，由于行为上的差异，我不想添加临时验证。这是可能的还是我只需要复制代码？

Answer 1

你能做的就是一个简单的构图。例如:

case class BaseModel(email: String, password: String)
case class ChildModel(name: String, website: String, base: BaseModel)

val commonMapping = mapping(
  "email" -> email,
  "passwod" -> texttext.verifying("Please provide a password", !_.isEmpty)
)(BaseModel.apply)(BaseModel.unapply)

val myExtendedForm = Form[ChildModel](mapping(
   "name" -> text,
   "website" -> text,
   "base" -> commonMapping
)
   ((name, website, base) => ChildModel(name, website, base))  //bind
   (child => Some(child.name, child.website, child.base))      //unbind
)