如何让打字稿停止抱怨它不知道的功能？ [英] How do I get typescript to stop complaining about functions it doesn't know about?

问题描述

我正在使用Typescript作为需要使用JavaScript全屏API的网络应用。全屏API尚未得到官方支持，因此您必须使用供应商前缀。这是我的代码，基于 MDN <的示例/ a>：

I'm using Typescript for a web app that needs to use the JavaScript full screen API. The full screen API isn't officially supported yet, so you have to use vendor prefixes. Here's my code, based on the sample from MDN:

function toggleFullScreen(element: JQuery) {
    var fs = element[0];
    if (!document.fullscreenElement &&    // alternative standard method
        !document.mozFullScreenElement && !document.webkitFullscreenElement && !document.msFullscreenElement) {  // current working methods
        if (fs.requestFullscreen) {
            fs.requestFullscreen();
        } else if (fs.msRequestFullscreen) {
            fs.msRequestFullscreen();
        } else if (fs.mozRequestFullScreen) {
            fs.mozRequestFullScreen();
        } else if (fs.webkitRequestFullscreen) {
            fs.webkitRequestFullscreen(Element.ALLOW_KEYBOARD_INPUT);
        }
    } else {
        if (document.exitFullscreen) {
            document.exitFullscreen();
        } else if (document.msExitFullscreen) {
            document.msExitFullscreen();
        } else if (document.mozCancelFullScreen) {
            document.mozCancelFullScreen();
        } else if (document.webkitExitFullscreen) {
            document.webkitExitFullscreen();
        }
    }
}

但是在我的IDE中（视觉效果） Studio，但这会发生在任何地方），我得到如下错误：

However in my IDE (Visual Studio, but this would happen anywhere), I get errors like:

The property 'fullscreenElement' does not exist on value of type 'Document'.
The property 'mozFullScreenElement' does not exist on value of type 'Document'.
The property 'webkitFullscreenElement' does not exist on value of type 'Document'.  

当然TypeScript不知道这些函数是否存在，但我也不想重新声明记录为任何只是为了摆脱这些错误，因为那样我将丢失所有其他类型的提示。

Of course TypeScript can't know that these functions exist, but nor do I want to re-declare document as any just to get rid of these errors, because then I'll lose all the other type hints.

这里有什么解决方案？我如何让TypeScript停止抱怨，但保留尽可能多的类型注释？

What is the solution here? How do I get TypeScript to stop complaining but keep as many type annotations as I can?

推荐答案

简单地说，你可以添加这些项目到文档界面，错误就会消失。

Simplistically, you could add those items to the Document interface and the errors would go away.

interface Document {
    exitFullscreen: any;
    mozCancelFullScreen: any;
    webkitExitFullscreen: any;
    fullscreenElement: any;
    mozFullScreenElement: any;
    webkitFullscreenElement: any;
}

你可以为每一个添加完整的类型信息，即使是简单的： / p>

You could add full type information for each of these, even the simple:

interface Document {
    exitFullscreen: () => void;
    mozCancelFullScreen: () => void;
    webkitExitFullscreen: () => void;
    fullscreenElement: () => void;
    mozFullScreenElement: () => void;
    webkitFullscreenElement: () => void;
}

这可以防止它们被误用。

This would prevent them being mis-used.

对于静态属性，您可能只需要使类型动态化，下面示例中的重要部分是元素上的类型断言，即（< any>元素）：

For static properties, you may just need to make the type dynamic, the important part in the example below is the type assertion on Element, i.e. (<any>Element):

fs.webkitRequestFullscreen((<any>Element).ALLOW_KEYBOARD_INPUT);

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