Vue初始化中的选项合并之initInternalComponent详解

export function initInternalComponent (vm: Component, options: InternalComponentOptions) {
 const opts = vm.$options = Object.create(vm.constructor.options)
 // doing this because it's faster than dynamic enumeration.
 const parentVnode = options._parentVnode
 opts.parent = options.parent
 opts._parentVnode = parentVnode

 const vnodeComponentOptions = parentVnode.componentOptions
 opts.propsData = vnodeComponentOptions.propsData
 opts._parentListeners = vnodeComponentOptions.listeners
 opts._renderChildren = vnodeComponentOptions.children
 opts._componentTag = vnodeComponentOptions.tag

 if (options.render) {
  opts.render = options.render
  opts.staticRenderFns = options.staticRenderFns
 }
}

export function createComponentInstanceForVnode (
 vnode: any, // we know it's MountedComponentVNode but flow doesn't
 parent: any, // activeInstance in lifecycle state
): Component {
 const options: InternalComponentOptions = {
  _isComponent: true,
  _parentVnode: vnode,
  parent
 }
 // check inline-template render functions
 const inlineTemplate = vnode.data.inlineTemplate
 if (isDef(inlineTemplate)) {
  options.render = inlineTemplate.render
  options.staticRenderFns = inlineTemplate.staticRenderFns
 }
 return new vnode.componentOptions.Ctor(options)
}

const opts = vm.$options = Object.create(vm.constructor.options)

const parentVnode = options._parentVnode
opts.parent = options.parent
opts._parentVnode = parentVnode

const vnodeComponentOptions = parentVnode.componentOptions
opts.propsData = vnodeComponentOptions.propsData
opts._parentListeners = vnodeComponentOptions.listeners
opts._renderChildren = vnodeComponentOptions.children
opts._componentTag = vnodeComponentOptions.tag

if (options.render) {
  opts.render = options.render
  opts.staticRenderFns = options.staticRenderFns
}