Action.async并在单独的函数中使用for-comprehension

Question

这可能比Play相关的Scala更多，但我在一些Play代码中遇到了这个问题。

我有

def index = Action.async { implicit request =>
  val content1Future = Blogs.getAllBlogs(request)
  val sidebar1Future = Blogs.getAllBlogsOverview(request)

  for {
    sidebar1 <- sidebar1Future
    content1 <- content1Future

    sidebar1Body <- Pagelet.readBody(sidebar1)
    content1Body <- Pagelet.readBody(content1)
  } yield {
    val sidebarcontents = List(sidebar1Body)
    val contents = List(content1Body)
    Ok(views.html.main("Index", contents, sidebarcontents)).withHeaders(("Cache-Control", "no-cache"))
}

它工作正常。

现在，我尝试将for-comprehention提取到一个单独的函数中来处理＆＃39; sidebar＆＃39;我想传递内容＆＃39;。

像

def index = Action.async { implicit request =>
  standardMain(Blogs.getAllBlogs(request))
}

def standardMain(content1Future: => Future[Result])(implicit request: Request[_]) : Future[Result] = { 
val sidebar1Future = Blogs.getAllBlogsOverview(request)

for {
  sidebar1 <- sidebar1Future
  content1 <- content1Future

  sidebar1Body <- Pagelet.readBody(sidebar1)
  content1Body <- Pagelet.readBody(content1)
} yield {
  val sidebarcontents = List(sidebar1Body)
  val contents = List(content1Body)
  Ok(views.html.main("Index", contents, sidebarcontents)).withHeaders(("Cache-Control", "no-cache"))
}

}

但后来我

[info]将1个Scala源编译为D：\ Dropbox \ Playground \ PlayWorld \ play-with-forms \ target \ scala-2.11 \ classes ...

[错误] D：\ Dropbox \ Playground \ PlayWorld \ play-with-forms \ app \ controllers \ Application.scala：91：type mismatch;

发现[错误]：scala.concurrent.Future [play.api.mvc.Result]

[error] required：play.api.libs.iteratee.Iteratee [Array [Byte]，？]

[error] content1＆lt; - content1Future

[错误] ^

[错误] D：\ Dropbox \ Playground \ PlayWorld \ play-with-forms \ app \ controllers \ Application.scala：90：type mismatch;

发现[错误]：play.api.libs.iteratee.Iteratee [Array [Byte]，Nothing]

[error] required：scala.concurrent.Future [play.api.mvc.Result]

[error] sidebar1＆lt; - sidebar1Future

[错误] ^

[错误]发现两个错误

[error]（编译：编译）编译失败

[错误]申请 -

我尝试了很多不同的调用，但不知怎的，我不知道如何获得play.api.libs.iteratee.Iteratee [Array [Byte]，？]。

我怎样才能实现这个目标。感谢。