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  • vue.js 源代码学习笔记 ----- instance proxy

    /* not type checking this file because flow doesn't play well with Proxy */
    
    import config from 'core/config'
    import { warn, makeMap } from '../util/index'
    
    let initProxy
    
    if (process.env.NODE_ENV !== 'production') {

    //一些能使用的全局变量 const allowedGlobals
    = makeMap( 'Infinity,undefined,NaN,isFinite,isNaN,' + 'parseFloat,parseInt,decodeURI,decodeURIComponent,encodeURI,encodeURIComponent,' + 'Math,Number,Date,Array,Object,Boolean,String,RegExp,Map,Set,JSON,Intl,' + 'require' // for Webpack/Browserify )
    //未定义缺使用了 const warnNonPresent
    = (target, key) => { warn( `Property or method "${key}" is not defined on the instance but ` + `referenced during render. Make sure to declare reactive data ` + `properties in the data option.`, target ) }
    //es6 proxy详解 const hasProxy
    = typeof Proxy !== 'undefined' && Proxy.toString().match(/native code/) if (hasProxy) { const isBuiltInModifier = makeMap('stop,prevent,self,ctrl,shift,alt,meta')
    //避免设置 系统鼠标 属性
       config.keyCodes
    = new Proxy(config.keyCodes, { set (target, key, value) { if (isBuiltInModifier(key)) { warn(`Avoid overwriting built-in modifier in config.keyCodes: .${key}`) return false } else { target[key] = value return true } } }) } const hasHandler = { has (target, key) { const has = key in target const isAllowed = allowedGlobals(key) || key.charAt(0) === '_' if (!has && !isAllowed) { warnNonPresent(target, key) }
    //如果有这个key 或者 不是全局函数, 返回true
    return has || !isAllowed } } const getHandler = { get (target, key) { if (typeof key === 'string' && !(key in target)) { warnNonPresent(target, key) } return target[key] } } initProxy = function initProxy (vm) { if (hasProxy) { // determine which proxy handler to use const options = vm.$options const handlers = options.render && options.render._withStripped ? getHandler : hasHandler vm._renderProxy = new Proxy(vm, handlers) } else { vm._renderProxy = vm } } } export { initProxy }

     此方法做了一些对象操作的拦截 和 警告

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  • 原文地址:https://www.cnblogs.com/dhsz/p/7116410.html
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