vue源码(一) – 初始化

new Vue({
  el: ...,
  data: ...,
  ...,
})

// Vue的核心方法
import Vue from './intance/index'
// 初始化一些全局API
import { initGlobalAPI } from './global-api/index'
// 判断是不是srr的变量
import { isServerRendering } from 'core/util/env'

// 执行初始化全局变量
initGlobalAPI(Vue)
// 为Vue原型定义属性$isServer
Object.defineProperty(Vue.prototype, '$isServer', {
  get () {
    /* istanbul ignore next */
    return this.$vnode && this.$vnode.ssrContext
  }
})

Vue.version = '__VERSION__'

export default Vue

import { initMixin } from './init'
import { stateMixin } from './state'
import { renderMixin } from './render'
import { eventsMixin } from './events'
import { lifecycleMixin } from './lifecycle'
import { warn } from '../util/index'

function  (options) {
  if (process.env.NODE_ENV !== 'production' && !(this instanceof Vue)) {
    warn('Vue is a constructor and should be called with the new keyword')
  }
  this._init(options)
}

initMixin(Vue)
stateMixin(Vue)
eventMixin(Vue)
lifecycleMixin(Vue)
renderMixin(Vue)

export default Vue

// core/global-api/index

...
export function initGlobalAPI (vue: GlobalAPI) {
  //config
  const configDef = {}
  configDef.get = () => config
  if (process.env.NODE_ENV !== 'production') {
    configDef.set = () => {
      warn(
        'Do not replace thi Vue.config object, set individual fields instead.'
      )
    }
  }
  Object.defineProperty(Vue, 'config', configDef)

  // 这些工具方法不视作全局API的一部分，除非你已经意识到某些风险，否则不要去依赖他们
  Vue.util = {
    warn,
    extend,
    mergeOptions,
    defineReactive
  }
  // 定义全局属性
  Vue.set = set
  Vue.delete = del
  Vue.nextTick = nextTick

  Vue.options = Object.create(null)
  ASSET_TYPES.forEach(type => {
    Vue.options[type + 's'] = Object.create(null)
  })
  Vue.options._base = Vue
  extend(Vue.options.components, buildInComponents)

  // 定义全局方法
  initUse(Vue)
  initMixin(Vue)
  initExtend(Vue)
  initAssetRegisters(Vue)
}