## 2-1 render.js (服务器渲染函数) >[info] import ~~~ ;(导入)节点组件创建 import { createComponentInstanceForVnode } from 'core/vdom/create-component' ~~~ >[info] module ~~~ export function createRenderFunction (modules, directives, isUnaryTag) { ;渲染节点 function renderNode (node, write, next, isRoot) { if (node.componentOptions) { const child = createComponentInstanceForVnode(node) renderNode(child._render(), write, next, isRoot) } else { if (node.tag) { renderElement(node, write, next, isRoot) } else { write(node.text, next) } } } ;渲染元素 function renderElement (el, write, next, isRoot) { if (isRoot) { if (!el.data) el.data = {} if (!el.data.attrs) el.data.attrs = {} el.data.attrs['server-rendered'] = 'true' } const startTag = renderStartingTag(el) const endTag = `</${el.tag}>` if (isUnaryTag(el.tag)) { write(startTag, next) } else if (!el.children || !el.children.length) { write(startTag + endTag, next) } else { write(startTag, () => { const total = el.children.length let rendered = 0 function renderChild (child) { renderNode(child, write, () => { rendered++ if (rendered < total) { renderChild(el.children[rendered]) } else { write(endTag, next) } }) } renderChild(el.children[0]) }) } } ;渲染标签 function renderStartingTag (node) { let markup = `<${node.tag}` if (node.data) { // check directives const dirs = node.data.directives if (dirs) { for (let i = 0; i < dirs.length; i++) { const dirRenderer = directives[dirs[i].name] if (dirRenderer) { // directives mutate the node's data // which then gets rendered by modules dirRenderer(node, dirs[i]) } } } // apply other modules for (let i = 0; i < modules.length; i++) { const res = modules[i](node) if (res) { markup += res } } } return markup + '>' } ;渲染接口 return function render (component, write, done) { renderNode(component._render(), write, done, true) } } ~~~ >[info] export ~~~ ;(导出)创建服务器渲染函数 export function createRenderFunction (modules, directives, isUnaryTag) { ~~~