Question

我正在使用scala的playframework，我正在尝试构建表单但是会出现以下错误

“找不到隐式的MessagesProvider实例。请参阅https://www.playframework.com/documentation/2.6.x/ScalaForms#Passing-MessagesProvider-to-Form-Helpers“ 这是我的index.scala.html

@(customerForm:Form[Customer])

@import helper._

@main("welcome") {
    <h1>Customer Form</h1>
    @form(action=routes.Application.createCustomer()) {
        @inputText(customerForm("Credit Limit"))
        @inputText(customerForm("Customer Name"))
        <input type="submit" value="Submit">
    }
}

这是我的应用程序控制器代码

package controllers

import play.api._
import play.api.mvc._
import models.Customer
import play.api.data._
import play.api.data.Forms._

class Application extends Controller {

  def customerForm = Form(mapping("Customer Name" -> nonEmptyText,
    "Credit Limit" -> number)(Customer.apply)(Customer.unapply))

  def index = Action { implicit request =>
    Ok(views.html.index(customerForm))
  }

  def createCustomer = Action { implicit request =>
    customerForm.bindFromRequest().fold(
      formWithErrors => BadRequest(views.html.index(formWithErrors)),
      customer => Ok(s"Customer ${customer.name} created successfully"))
  }

}

Answer 1

播放框架表单处理在版本2.5和2.6之间已经改变，为了使事情工作，您必须更改Application类的声明，如下所示：

import javax.inject._
import play.api.i18n.I18nSupport

class Application @Inject()(val cc: ControllerComponents) extends AbstractController(cc) with I18nSupport

并在您的视图中添加隐式参数，如下所示：

@(customerForm:Form[Customer])(implicit request: RequestHeader, messagesProvider: MessagesProvider)

如果您在视图中不需要RequestHeader，则可以省略其声明。

有关详细信息，请参阅错误消息中的链接： https://www.playframework.com/documentation/2.6.x/ScalaForms#Passing-MessagesProvider-to-Form-Helpers

Answer 2

我遇到了同样的错误，就我而言，我忘记了使请求隐式。我希望此答案对您有所帮助，如果您按照Achraf的回答更改了代码，但仍然出现错误。

def foo() = Action { implicit request =>
    Ok(html.index(form))
}

使用scala在Play框架中找不到Implicit Messages Provider实例

2 个答案: