chrome extensions mv3通过content scripts注入/获取原网站的window数据

开发插件的都知道插件的content scripts和top window只共享Dom不共享window和其他数据，如果想拿挂载在window的数据还有点难度，下面会通过事件的方式传递cs和top window之间的数据写一个例子

代码

manifest.json

这里只搞了2个js，content.js是content scripts，main.js是在top window里运行的

{"version": "0.0.1","author": "apades","name": "ext-hack","description": "","manifest_version": 3,"content_scripts": [{"matches": ["<all_urls>"],"js": ["content.js"],"run_at": "document_end","all_frames": true},{"matches": ["<all_urls>"],"js": ["main.js"],"run_at": "document_end","world": "MAIN"}]
}

content.js

async function sendExtMessage(type, data) {window.dispatchEvent(new CustomEvent('ext-req', { detail: { type, data } }))return new Promise((res) => {function handleResponse(e) {const detail = e.detailif (detail.type == type) {window.removeEventListener('ext-res', handleResponse)return res(detail.data)}}window.addEventListener('ext-res', handleResponse)})
}// 暴露到content script的window里测试
window.sendExtMessage = sendExtMessage

main.js

window.addEventListener('ext-req', async (e) => {const { type, data } = e.detailswitch (type) {case 'run-code': {let fn = new Function(`return (${data.function})(...arguments)`)let rs = await fn(...(data.args ?? []))sendExtResponse(type, rs)break}}
})function sendExtResponse(type, data) {window.dispatchEvent(new CustomEvent('ext-res', {detail: { type, data },}))
}

运行测试

首先我先在top window里随便写个window.a的值

然后切换到ext-hack的window里，再测试sendExtMessage

然后发现可以拿到top window的数据了；以上方法还能传入content script window里的对象参数到top window里使用，也可以传入异步方法

最后要说的

通过事件里互相传的数据会经过插件内部的序列化，地址、Object.defineProperty都是不共享的。而且这个方法相较于script标签插入，可以绕开doc response的Content-Security-Policy