function initEvents (vm: Component) { vm._events = Object.create(null) vm._hasHookEvent = false // init parent attached events const listeners = vm.$options._parentListeners if (listeners) { updateComponentListeners(vm, listeners) } }
又新增两个属性，后面那个if条件里面是有父组件的事件时初始化，估计就是props和events父子组件通信的事件内容。
3.initRender
function initRender (vm: Component) { vm._vnode = null // the root of the child tree vm._staticTrees = null const parentVnode = vm.$vnode = vm.$options._parentVnode const renderContext = parentVnode && parentVnode.context vm.$slots = resolveSlots(vm.$options._renderChildren, renderContext) vm.$scopedSlots = emptyObject vm._c = (a, b, c, d) => createElement(vm, a, b, c, d, false) vm.$createElement = (a, b, c, d) => createElement(vm, a, b, c, d, true) const parentData = parentVnode && parentVnode.data /* istanbul ignore else */ if (process.env.NODE_ENV !== 'production') { defineReactive(vm, '$attrs', parentData && parentData.attrs, () => { !isUpdatingChildComponent && warn(`$attrs is readonly.`, vm) }, true) defineReactive(vm, '$listeners', vm.$options._parentListeners, () => { !isUpdatingChildComponent && warn(`$listeners is readonly.`, vm) }, true) } else { defineReactive(vm, '$attrs', parentData && parentData.attrs, null, true) defineReactive(vm, '$listeners', vm.$options._parentListeners, null, true) } }
此函数也是初始化了节点属性信息，绑定createElement函数到实例【并未挂载】，接下来调用beforeCreate回调钩子；——TODO1：后续专题分析VUE渲染逻辑
4.initInjections
function initInjections (vm: Component) { const result = resolveInject(vm.$options.inject, vm) if (result) { observerState.shouldConvert = false Object.keys(result).forEach(key => { /* istanbul ignore else */ if (process.env.NODE_ENV !== 'production') { defineReactive(vm, key, result[key], () => { warn( `Avoid mutating an injected value directly since the changes will be ` + `overwritten whenever the provided component re-renders. ` + `injection being mutated: "${key}"`, vm ) }) } else { defineReactive(vm, key, result[key]) } }) observerState.shouldConvert = true } }
此函数也是当有inject属性时做处理，源码例子无inject断点跑暂时跳过
5.initState
function initState (vm: Component) { vm._watchers = [] const opts = vm.$options if (opts.props) initProps(vm, opts.props) if (opts.methods) initMethods(vm, opts.methods) if (opts.data) { initData(vm) } else { observe(vm._data = {}, true /* asRootData */) } if (opts.computed) initComputed(vm, opts.computed) if (opts.watch && opts.watch !== nativeWatch) { initWatch(vm, opts.watch) } }
可以看出此处是对options传入的props/methods/data/computed/watch属性做初始化————TODO2：分析每个属性的初始化
6.initProvide
function initProvide (vm: Component) { const provide = vm.$options.provide if (provide) { vm._provided = typeof provide === 'function' ? provide.call(vm) : provide } }
这个函数跟4.initInjections在同一个inject.js中，也是在传入参数有provide属性时做处理，暂时跳过，然后就到了created回调钩子，最后的vm.$mount接入TODO1；