Question

我正在尝试使用Play Framework 2.5.3在本地测试示例路径变量。

 package controllers

 import play.api._
 import play.api.data._
 import play.api.data.Forms._
 import play.api.mvc._
 import play.api.libs.json._
 import play.api.libs.json.Json._
 import play.api.libs.functional.syntax._

 case class Product(sku: String, title: String)
 object Product {
implicit def pathBinder(implicit stringBinder: PathBindable[String]) = new PathBindable[Product] {
  override def bind(key: String, value: String): Either[String, Product]    = {
    for {
      sku <- stringBinder.bind(key, value).right
      product <- productMap.get(sku).toRight("Product not found").right
    } yield product
  }
  override def unbind(key: String, product: Product): String = {
    stringBinder.unbind(key, product.sku)
  }
 }

def add(product: Product) = productMap += (product.sku -> product)

val productMap = scala.collection.mutable.Map(
    "ABC" -> Product("ABC", "8-Port Switch"),
    "DEF" -> Product("DEF", "16-Port Switch"),
    "GHI" -> Product("GHI", "24-Port Switch")
)
}

object Products extends Controller {
  implicit val productWrites = new Writes[Product] {
  def writes(product: Product) = Json.obj(
    "sku" -> product.sku,
    "title" -> product.title
    )
  }

implicit val productReads: Reads[Product] = (
(JsPath \ "sku").read[String] and
(JsPath \ "title").read[String]
)(Product.apply _)

val productForm: Form[Product] = Form(
  mapping(
    "sku" -> nonEmptyText,
    "title" -> nonEmptyText
  )(Product.apply)(Product.unapply)
)

def index = Action {
    Ok(toJson(Product.productMap.values))
}

def postProduct = Action(BodyParsers.parse.json) { request =>
    val post = request.body.validate[Product]
  post.fold(
    errors => {
      BadRequest(Json.obj("status" ->"error", "message" -> JsError.toFlatJson(errors)))
    },
    product => { 
        Product.add(product)
      Created(toJson(product))
    }
  )
}

def edit(product: Product) = Action {
    Ok(views.html.products.form(product.sku, productForm.fill(product)))
}

def update(sku: String) = Action {
    Ok("Received update request")
}

}

以下是我的观点。

  @(sku: String, productForm: Form[controllers.Product])

  @helper.form(action = routes.Products.update(sku)) {
  @helper.inputText(productForm("sku"))
  @helper.inputText(productForm("title"))
  }

当我编译这个程序时，我收到了以下错误

 [error] /home/rajkumar/CodeBase/workspaceEclipse/PFC2/app/views/products/form.scala.html:4: could not find implicit value for parameter messages: play.api.i18n.Messages
  [error]   @helper.inputText(productForm("sku"))
   [error]                    ^
  [error] /home/rajkumar/CodeBase/workspaceEclipse/PFC2/app/views/products/form.scala.html:5: could not find implicit value for parameter messages: play.api.i18n.Messages
  [error]   @helper.inputText(productForm("title"))
   [error]                    ^
  [error] 9 errors found
  [error] (compile:compileIncremental) Compilation failed

任何人都可以帮我解决这个问题。

Answer 1

正如@ jirka-helmich指出的那样，@ jerry的解决方案已被弃用。

Play 2.5.x documentation列出了以下解决方案（请注意I18nSupport特性）：

import javax.inject.Inject
import play.api.i18n.I18nSupport
class MyController @Inject()(val messagesApi: MessagesApi) extends Controller with I18nSupport {
// ...

有关详细信息，请参阅this answer。

Answer 2

当您使用 inputText 时，需要“隐含消息”。通过导入以下语句添加它

import play.api.Play.current
import play.api.i18n.Messages.Implicits._

在视图中，您需要添加以下代码

@(sku: String, productForm: Form[controllers.Product])(implicit messages: Messages)

参考Play 2.4: Form: could not find implicit value for parameter messages: play.api.i18n.Messages

找不到参数消息的隐含值：Play.api.i18n.Messages在Play Framework 2.5.3中

2 个答案: