问题描述
我正在尝试在Kotlin中编写一个小型的node.js应用程序，以测试和使用javascript互操作.从一个暴露了原型"Bar"的外部节点模块"foo"中，我试图创建一个"Bar"的新实例.
I'm trying to write a small node.js application in Kotlin to test and play with the javascript interop. From an external node module 'foo' which exposes a prototype 'Bar', I am trying to create a new instance of 'Bar'.
在Javascript中，我只会写类似
In Javascript I would simply write something like
var foo = require('foo')
var bar = new foo.Bar()
在Kotlin中，我定义了一个外部函数'require'并加载了按预期工作的模块:
In Kotlin, I defined an external function 'require' and load the module which works as expected:
external fun require(module: String): dynamic
...
val foo = require("foo")
//Somehow create a new Bar
现在，我想创建一个Bar的新实例.到目前为止，我已经尝试过:
Now I would like to create a new instance of Bar. So far I've tried:
- 呼叫
val bar = foo.Bar().这被解释为功能，因此不起作用. - 定义外部类Bar并创建一个新对象
val bar = Bar()
- Calling
val bar = foo.Bar(). This is interpreted as function and thus doesn't work. - Defining an external class Bar and creating a new object
val bar = Bar()
我只能找到的唯一解决方法是通过本机JavaScript代码val bar = js("new foo.Bar()")实例化该对象.这可行，但有一些缺点:
The only workaround I could find is to instantiate the object via native javascript code: val bar = js("new foo.Bar()"). This works, but has a few disadvantages:
- 它不是类型安全的(这是使用kotlin的优点之一)
- 它与变量foo有隐式依赖关系，在编译时不会对其进行检查
- 该模块使用许多不同的构造函数参数公开了许多此类对象，这将导致产生大量如上所述的本机代码，
有什么方法可以实现这一目标，最好是在纯Kotlin中实现?
Is there any way to achieve this, prefearably in pure kotlin?
推荐答案
我想您必须将Bar定义为模块foo中的外部类:
I guess you have to define Bar as an external class from module foo:
@JsModule("foo")
external class Bar {
...
}
请参见 https://kotlinlang.org/docs/reference/js-modules. html 和 https://kotlinlang.org/docs/reference/js- interop.html
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