scala 在 Play Framework 2.0 模板中使用选项助手
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Use of option helper in Play Framework 2.0 templates
提问by UltraMaster
I'm trying to use views.html.helper.select(documentation here). I don't know scala, so i'm using java. I need to pass object of type Seq[(String)(String)] to the template right? Something like:
我正在尝试使用views.html.helper.select（此处的文档）。我不知道 Scala，所以我使用的是 java。我需要将 Seq[(String)(String)] 类型的对象传递给模板，对吗？就像是：
@(fooForm:Form[Foo])(optionValues:Seq[(String)(String)])
@import helper._
@form(routes.foo){
@select(field=myForm("selectField"),options=optionValues)
}
I don't know how to create Seq[(String)(String)] in java. I need to fill this collection with pairs (id,title) from my enum class.
我不知道如何在 java 中创建 Seq[(String)(String)]。我需要用我的枚举类中的对 (id,title) 填充这个集合。
Can somebody show me some expample how to use the select helper?
有人可以告诉我一些如何使用选择助手的示例吗？
I found thisthread on users group, but Kevin's answer didn't helped me a lot.
我在用户组上找到了这个线程，但凯文的回答对我没有多大帮助。
回答by Julien Richard-Foy
The right type is: Seq[(String, String)]. It means a sequence of pairs of String. In Scala there is a way to define pairs using the arrow: a->b == (a, b). So you could write e.g.:
正确的类型是：Seq[(String, String)]。它表示字符串对的序列。在 Scala 中有一种使用箭头定义对的方法：a->b == (a, b)。所以你可以写例如：
@select(field = myForm("selectField"), options = Seq("foo"->"Foo", "bar"->"Bar"))
But there is another helper, as shown in the documentation, to build the sequence of select options: options, so you can rewrite the above code as:
但是还有另一个帮助程序，如文档中所示，用于构建选择选项的序列：options，因此您可以将上述代码重写为：
@select(myForm("selectField"), options("foo"->"Foo", "bar"->"Bar"))
In the case your options values are the same as their label, you can even shorten the code to:
如果您的选项值与其标签相同，您甚至可以将代码缩短为：
@select(myForm("selectField"), options(List("Foo", "Bar")))
(note: in Play 2.0.4 options(List("Foo", "Bar"))doesn't compile, so you can try this options(Seq("Foo", "Bar")))
（注意：在 Play 2.0.4options(List("Foo", "Bar"))中不能编译，所以你可以试试这个options(Seq("Foo", "Bar"))）
To fill the options from Java code, the more convenient way is to use either the overloaded optionsfunction taking a java.util.List<String>as parameter (in this cases options values will be the same as their label) or the overloaded function taking a java.util.Map<String, String>.
要从 Java 代码填充选项，更方便的方法是使用options以 ajava.util.List<String>作为参数的重载函数（在这种情况下，选项值将与其标签相同）或使用java.util.Map<String, String>.
