vue.js 源代碼學習筆記 ----- instance inject

/* @flow */import { hasSymbol } from 'core/util/env'
import { warn } from '../util/index'
import { defineReactive } from '../observer/index'export function initProvide (vm: Component) {const provide = vm.$options.provideif (provide) {
　　// 計算proved結果vm._provided = typeof provide === 'function'? provide.call(vm): provide}
}export function initInjections (vm: Component) {const inject: any = vm.$options.injectif (inject) {// inject is :any because flow is not smart enough to figure out cached// isArray here
　　// 注入 可以任何類型 是因為fow不過智能, 計算出被緩存的數組
const isArray = Array.isArray(inject)
　　//如果是對象, 取出屬性值const keys = isArray? inject: hasSymbol? Reflect.ownKeys(inject): Object.keys(inject)for (let i = 0; i < keys.length; i++) {const key = keys[i]const provideKey = isArray ? key : inject[key]let source = vm
while (source) {if (source._provided && provideKey in source._provided) {/* istanbul ignore else */if (process.env.NODE_ENV !== 'production') {
　　　　　　 //添加這個vm的inject屬性監控defineReactive(vm, key, source._provided[provideKey], () => {     //避免直接監控一個屬性, 因為當重新渲染的時候, 這個監控會被改變
　　　　　　　　warn(`Avoid mutating an injected value directly since the changes will be ` +`overwritten whenever the provided component re-renders. ` +`injection being mutated: "${key}"`,vm)})} else {defineReactive(vm, key, source._provided[provideKey])}break}source = source.$parent}}}
}

?這個方法應該是給vm的inject屬性添加監控.