可以从 Chrome 扩展程序修改窗口对象吗? [英] Can the window object be modified from a Chrome extension?

问题描述

我想制作一个 Chrome 扩展程序，在 window 内提供一个新对象.当在加载了扩展程序的浏览器中查看网页时，我希望 window.mything 可以通过 Javascript 访问.window.mything 对象将有一些我将在扩展中定义的函数，这些函数应该可以在查看页面时从 console.log 或任何 Javascript 文件中调用在启用了扩展的浏览器中.

I would like to make a Chrome extension that provides a new object inside window. When a web page is viewed in a browser with the extension loaded, I would like window.mything to be available via Javascript. The window.mything object will have some functions that I will define in the extension, and these functions should be callable from console.log or any Javascript file when the page is viewed in a browser with the extension enabled.

通过使用内容脚本:

var s = document.createElement("script"); 
s.src = chrome.extension.getURL("mything.js");
document.getElementsByTagName("head")[0].appendChild(s);

mything.js 看起来像这样:

mything.js looks like this:

window.mything = {thing: true};
console.log(window);

每当页面加载时，我都会看到整个 window 对象，正如我期望它在控制台中一样.但是，我无法从控制台与 window.mything 对象交互.似乎注入的脚本并没有真正修改全局 window 对象.

Whenever a page loads, I see the entire window object as I expect it to be in the console. However, I can't interact with the window.mything object from the console. It seems at if the injected script hasn't really modified the global window object.

如何从 Chrome 扩展程序修改全局 window 对象?

How can I modify the global window object from a Chrome extension?

推荐答案

你不能，不能直接.来自内容脚本文档:

You can't, not directly. From the content scripts documentation:

但是，内容脚本有一些限制.他们不能:

However, content scripts have some limitations. They cannot:

• 使用 chrome.* API(chrome.extension 的部分除外)
• 使用由其扩展页面定义的变量或函数
• 使用由网页或其他内容脚本定义的变量或函数

(强调)

内容脚本看到的 window 对象与页面看到的 window 对象不同.

The window object the content script sees is not the same window object that the page sees.

您可以通过 DOM 传递消息，但是，使用 window.postMessage 方法.您的页面和内容脚本都会监听 message 事件，每当您从其中一个地方调用 window.postMessage 时，另一个地方都会收到它.内容脚本"文档页面上有一个此示例.

You can pass messages via the DOM, however, by using the window.postMessage method. Both your page and content script listen to the message event, and whenever you call window.postMessage from one of those places, the other will receive it. There's an example of this on the "Content Scripts" documentation page.

您可以通过从内容脚本中注入脚本来向页面添加一些方法.尽管如此，它仍然无法与扩展的其余部分进行通信，而不使用诸如 postMessage 之类的东西，但您至少可以向页面的 window 添加一些内容

edit: You could potentially add some methods to the page by injecting a script from the content script. It still wouldn't be able to communicate back with the rest of the extension though, without using something like postMessage, but you could at least add some things to the page's window

var elt = document.createElement("script");
elt.innerHTML = "window.foo = {bar:function(){/*whatever*/}};"
document.head.appendChild(elt);

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