Chrome 扩展：在页面加载前注入 JS
[英]Chrome extension: Inject JS before page load
问题描述
Is it possible to inject JS before page load, or is it necessary to use content scripts and way for the document to finish?
是否可以在页面加载之前注入 JS，或者是否需要使用内容脚本和方式来完成文档？
For example, is there a faster way to execute JS that turns the page red as soon as it's opened?比如有没有更快的方式来执行一打开页面就变红的JS？
2 个解决方案
解决方案1
61 已采纳 2013-10-04 22:56:17
Declare a content script in the manifest file with "run_at": "document_start" to get it to run as soon as possible, ie right after constructing the document root (when <head> does not exist yet).在清单文件中使用"run_at": "document_start"声明内容脚本以使其尽快运行，即在构建文档根目录之后（当<head>尚不存在时）。
For your very specific example, it might be better to declare a content style instead, similar to content scripts, but using the "css" key instead of "js" .对于您非常具体的示例，最好改为声明内容样式，类似于内容脚本，但使用"css"键而不是"js" 。
If you want to dynamically run a script as soon as possible, then call chrome.tabs.executeScript when the chrome.webNavigation.onCommitted event is triggered.如果您想尽快动态运行脚本，则在触发chrome.webNavigation.onCommitted事件时调用chrome.tabs.executeScript 。
解决方案2
1 2023-01-22 18:44:35
For Manifest V3 there was a new field added to content scripts in 102.0.5005.58 Stable: world对于 Manifest V3，在 102.0.5005.58 稳定版中的内容脚本中添加了一个新字段： world
And there are also a lot of chrome bugs related to that topic: #634381 , #1054624 , #1207006还有很多与该主题相关的 chrome 错误： #634381 、 #1054624 、 #1207006
You have to use "world": "main" at the content script together with "run_at": "document_start" and a CSP to allow the injection from the Extension.您必须在内容脚本中使用"world": "main"以及"run_at": "document_start"和 CSP 以允许从扩展中注入。 Otherwise the injected script gets rejected with:否则注入的脚本会被拒绝：
Refused to execute inline script because it violates the following Content Security Policy directive: "script-src 'self' 'wasm-unsafe-eval'".
"world": "MAIN": “世界”：“主要”：
[Extensions] Add main world injections for dynamic content scripts
This CL adds a new field "world" for dynamic content scripts which allows the extension to specify if the script will run in the isolated or main world.
Valid attributes are "ISOLATED" (default) or "MAIN" .有效属性是"ISOLATED" （默认）或"MAIN" 。
Example files i used:我使用的示例文件：
manifest.json清单.json
{
"name": "script injection",
"version": "0",
"manifest_version": 3,
"minimum_chrome_version": "103.0",
"content_scripts": [
{
"matches": ["*://*/*"],
"js": ["inject.js"],
"run_at": "document_start",
"world": "MAIN"
}
],
"web_accessible_resources": [{
"resources": ["injected.js"],
"matches": ["<all_urls>"]
}],
"content_security_policy": {
"extension_pages": "default-src 'self' 'wasm-unsafe-eval';"
}
}
inject.js注入.js
let el = document.createElement("script");
el.src = chrome.runtime.getURL("injected.js");
document.documentElement.appendChild(el);
console.log("injected");
injected.js注入.js
console.log(typeof alert); // "function"
console.log("injected file");
delete window.alert;
console.log(typeof alert); // "undefined"
[ [ ]
]
声明:本站的技术帖子网页，遵循CC BY-SA 4.0协议，如果您需要转载，请注明本站网址或者原文地址。任何问题请咨询:yoyou2525@163.com.