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Hook Vue3 app

通过劫持Proxy方法，逆向还原Vue3 app元素到DOM

此脚本不应直接安装。它是供其他脚本使用的外部库，要使用该库请加入元指令 // @require https://updategreasyfork.deno.dev/scripts/449444/1081400/Hook%20Vue3%20app.js 

// ==UserScript==
// @name         Hook Vue3 app
// @version      1.0.3
// @description  通过劫持Proxy方法，逆向还原Vue3 app元素到DOM
// @author       DreamNya
// @license      MIT
// @namespace https://gf.zukizuki.org/users/809466
// ==/UserScript==

const $window = window.unsafeWindow || document.defaultView || window
const realLog = $window.console.log; //反劫持console.log（大部分网站都会劫持console.log）
const realProxy = $window.Proxy; //劫持Proxy

var vueUnhooked = new WeakSet() //以WeakSet存储已获取到但未未劫持的app对象，作为debug用变量，正常情况WeakSet应为空
var vueHooked = new WeakMap() //以WeakMap存储已劫持的app对象，DOM元素为key，app对象为value

$window.Proxy = function () {
    let app = arguments[0]._
    if (app?.uid >= 0) { //判断app
        let el = app.vnode.el
        if (el) {
            recordVue(el, app) //记录到WeakMap
            recordDOM(el, app) //挂载到DOM
            watch_isUnmounted(app) //观察销毁
        } else {
            //realLog(app,el)
            vueUnhooked.add(app) //记录未劫持的app
            //realLog(vueUnhooked,app)
            watchEl(app.vnode) //不存在el则观察el
        }
    }
    return new realProxy(...arguments)
}

function watchEl(vnode) { //观察el 变动时还原到DOM
    let value = vnode.el
    let hooked = false
    Object.defineProperty(vnode, "el", {
        get() {
            return value
        },
        set(newValue) {
            value = newValue
            if (!hooked && this.el) {
                hooked = true
                recordVue(this.el, this.component)
                recordDOM(this.el, this.component)
                watch_isUnmounted(this.component)
                //realLog(this.component,"已还原")
            }
        }
    })
}

function watch_isUnmounted(app) { //观察isUnmounted 变动时销毁引用
    let value = app.isUnmounted
    let unhooked = false
    Object.defineProperty(app, "isUnmounted", {
        get() {
            return value
        },
        set(newValue) {
            value = newValue
            if (!unhooked && this.isUnmounted) {
                unhooked = true
                //realLog(this,"已删除")
                let el = this.vnode.el
                if (el) {
                    let DOMvalue = el.__vue__ //删除DOMelement.__vue__挂载
                    if (DOMvalue) {
                        if (Array.isArray(DOMvalue)) {
                            let index = DOMvalue.findIndex(i => i == this)
                            index > -1 && DOMvalue.splice(index, 1)
                            el.__vue__ = DOMvalue.length > 1 ? DOMvalue : DOMvalue[0]
                        } else {
                            if (DOMvalue == this) {
                                el.__vue__ = void 0
                            }
                        }
                    }
                    let WMvalue = vueHooked.get(el) //删除WeakMap存储
                    if (WMvalue) {
                        if (Array.isArray(WMvalue)) {
                            let index = WMvalue.findIndex(i => i == this)
                            index > -1 && WMvalue.splice(index, 1)
                            vueHooked.set(el, WMvalue.length > 1 ? WMvalue : WMvalue[0])
                        } else {
                            if (WMvalue == this) {
                                vueHooked.delete(el)
                            }
                        }
                    }
                }
            }
        }
    })
}

function recordVue(el, app) { //将app记录到WeakMap中
    vueUnhooked.delete(app)
    if (vueHooked.has(el)) {
        let value = vueHooked.get(el)
        if (Array.isArray(value)) {
            if (value.findIndex(i => i == app) == -1) {
                vueHooked.set(el, vueHooked.get(el).push(app))
            }
        } else {
            if (value != app) {
                vueHooked.set(el, [value, app])
            }
        }
    } else {
        vueHooked.set(el, app)
    }
}

function recordDOM(el, app) { //将app挂载到DOMelement.__vue__
    if (el.__vue__) {
        let value = el.__vue__
        if (Array.isArray(value)) {
            if (value.findIndex(i => i == app) == -1) {
                el.__vue__ = value.push(app)
            }
        } else {
            if (value != app) {
                el.__vue__ = [value, app]
            }
        }
    } else {
        el.__vue__ = app
    }
}