qiankun
qiankun分为accpication和parcel模式。
aplication模式基于路由工作,将应用分为两类,基座应用和子应用,基座应用维护路由注册表,根据路由的变化来切换子应用。子应用是一个独立的应用,需要提供生命周期方法供基座应用使用。
parcel模式和路由无关,子应用切换是手动控制的,具体是通过qiankun提供的loadMicroApp来实现的。
js隔离机制
乾坤有三种js隔离机制,SnapshotSandbox
LegacySandbox
ProxySandbox
SnapshotSandBox 快照沙箱
class SnapshotSandBox{windowSnapshot = {};modifyPropsMap = {};active(){for(const prop in window){this.windowSnapshot[prop] = window[prop];}Object.keys(this.modifyPropsMap).forEach(prop=>{window[prop] = this.modifyPropsMap[prop];});}inactive(){for(const prop in window){if(window[prop] !== this.windowSnapshot[prop]){this.modifyPropsMap[prop] = window[prop];window[prop] = this.windowSnapshot[prop];}}}
}
// 验证:
let snapshotSandBox = new SnapshotSandBox();
snapshotSandBox.active();
window.city = 'Beijing';
console.log("window.city-01:", window.city);
snapshotSandBox.inactive();
console.log("window.city-02:", window.city);
snapshotSandBox.active();
console.log("window.city-03:", window.city);
snapshotSandBox.inactive();//输出:
//window.city-01: Beijing
//window.city-02: undefined
//window.city-03: Beijing
- 沙箱激活: 微应用处于运行中,这个阶段可能会对window上的属性操作进行改变。
- 沙箱失活: 就是微应用停止了对window的影响
- 在沙箱激活的时候:记录window当时的状态(我们把这个状态称之为快照,也就是快照沙箱这个名称的来源),恢复上一次沙箱失活时记录的沙箱运行过程中对window做的状态改变,也就是上一次沙箱激活后对window做了哪些改变,现在也保持一样的改变。
- 沙箱失活: 记录window上有哪些状态发生了变化(沙箱自激活开始,到失活的这段时间);清除沙箱在激活之后在window上改变的状态,从代码可以看出,就是让window此时的属性状态和刚激活时候的window的属性状态进行对比,不同的属性状态就以快照为准,恢复到未改变之前的状态。
这种沙箱无法同时运行多个微应用
LegacySandBox 代理沙箱
class LegacySandBox{addedPropsMapInSandbox = new Map();modifiedPropsOriginalValueMapInSandbox = new Map();currentUpdatedPropsValueMap = new Map();proxyWindow;setWindowProp(prop, value, toDelete = false){if(value === undefined && toDelete){delete window[prop];}else{window[prop] = value;}}active(){this.currentUpdatedPropsValueMap.forEach((value, prop)=>this.setWindowProp(prop, value));}inactive(){this.modifiedPropsOriginalValueMapInSandbox.forEach((value, prop)=>this.setWindowProp(prop, value));this.addedPropsMapInSandbox.forEach((_, prop)=>this.setWindowProp(prop, undefined, true));}constructor(){const fakeWindow = Object.create(null);this.proxyWindow = new Proxy(fakeWindow,{set:(target, prop, value, receiver)=>{const originalVal = window[prop];if(!window.hasOwnProperty(prop)){this.addedPropsMapInSandbox.set(prop, value);}else if(!this.modifiedPropsOriginalValueMapInSandbox.has(prop)){this.modifiedPropsOriginalValueMapInSandbox.set(prop, originalVal);}this.currentUpdatedPropsValueMap.set(prop, value);window[prop] = value;},get:(target, prop, receiver)=>{return target[prop];}});}
}
// 验证:
let legacySandBox = new LegacySandBox();
legacySandBox.active();
legacySandBox.proxyWindow.city = 'Beijing';
console.log('window.city-01:', window.city);
legacySandBox.inactive();
console.log('window.city-02:', window.city);
legacySandBox.active();
console.log('window.city-03:', window.city);
legacySandBox.inactive();
// 输出:
// window.city-01: Beijing
// window.city-02: undefined
// window.city-03: Beijing
ProxySandBox 代理沙箱
class ProxySandBox{proxyWindow;isRunning = false;active(){this.isRunning = true;}inactive(){this.isRunning = false;}constructor(){const fakeWindow = Object.create(null);this.proxyWindow = new Proxy(fakeWindow,{set:(target, prop, value, receiver)=>{if(this.isRunning){target[prop] = value;}},get:(target, prop, receiver)=>{return prop in target ? target[prop] : window[prop];}});}
}
// 验证:
let proxySandBox1 = new ProxySandBox();
let proxySandBox2 = new ProxySandBox();
proxySandBox1.active();
proxySandBox2.active();
proxySandBox1.proxyWindow.city = 'Beijing';
proxySandBox2.proxyWindow.city = 'Shanghai';
console.log('active:proxySandBox1:window.city:', proxySandBox1.proxyWindow.city);
console.log('active:proxySandBox2:window.city:', proxySandBox2.proxyWindow.city);
console.log('window:window.city:', window.city);
proxySandBox1.inactive();
proxySandBox2.inactive();
console.log('inactive:proxySandBox1:window.city:', proxySandBox1.proxyWindow.city);
console.log('inactive:proxySandBox2:window.city:', proxySandBox2.proxyWindow.city);
console.log('window:window.city:', window.city);
// 输出:
// active:proxySandBox1:window.city: Beijing
// active:proxySandBox2:window.city: Shanghai
// window:window.city: undefined
// inactive:proxySandBox1:window.city: Beijing
// inactive:proxySandBox2:window.city: Shanghai
// window:window.city: undefined
支持一个页面运行多个微应用
资源加载
- 通过registerMicroApps注册微应用
- 通过loadMicroApp手动加载微应用
- 调用start时触发了预加载逻辑
- 手动调用prefetchApps执行加载
export function registerMicroApps<T extends objectType>(apps: Array<RegistrableApp<T>, lifeCycles?: FrameworkLifeCycles<T>,) {unregisteredApps.forEach((app) => {const {name, activeRule, loader = noop, porps, ...appConfig} = appregisterApplication({name,app: async() => {const {mount, ...otherMicroAppConfig} = {await loadApp({name, props, ...appConfig}, frameworkConfiguration, lifeCycles)()return {mount: [async () => loader(true), ...toArray(mount), async() => loader(false)],...otherMicroAppConfigs,}}activeWhen: activeRule,customProps: props} })})
}
- name: 子应用的唯一标识
- entry: 子应用的入口
- container: 子应用挂载的节点
- activeRule: 子应用激活的条件。
loadApp的主体流程
核心功能: 获取微应用的js/css/html等资源,并对这些资源进行加工,然后构造和执行生命周期中需要执行的方法。最后返回一个函数,这个函数的返回值是一个对象,该对象包含了微应用的生命周期方法。
获取微应用资源的方法
依赖了库import-html-entry
的importEntry函数。
const {template, execScripts, assetPublicPath} = await importEntry(entry, importEntryOpts)
// template: 一个字符串,内部包含了html、css资源
// assetPublicPath:访问页面远程资源的相对路径
// execScripts:一个函数,执行该函数后会返回一个对象
将获取的template涉及的html/css转换为dom节点
const appContent = getDefaultTplWrapper(appInstanceId)(template)
let initialAppWrapperElement: HTMLElement | null = createElement(appContent,strictStyleIsop,scopedCSS, appInstanceId
)
export function getDefaultTplWrapper(name: string) {return (tpl: string) => `<div id="${getWrapperId(name)}" data-name="${name}" data-version="${version}">${tpl}</div>`;
}
function createElement(appContent: string,strictStyleIsolation:boolean,scopedCSS: boolean,appInstanceId: string
): HTMLElement {const containerElement = document.createElement('div')containerElement.innerHTML = appContainerconst appELement = containerElement.firstChild as HTMLElementreturn appElement
}
css资源的处理和隔离方法
if(scopedCSS) {const attr = appElement.getAttribute(css.QiankunCSSRewriteAttr)if(!attr) {appElement.setAttribute(css.QiankunCSSRewriteAttr, appInstanceId)}const styleNodes = appElement.querySelectorAll('style') || []forEach(styleNodes, (stylesheetElement: HTMLStyleElement) => {css.process(appElement!, stylesheetElement, appInstanceId)})
}
关于函数initialAppWrapperGetter
// 代码片段五,所属文件:src/loader.tsconst initialAppWrapperGetter = getAppWrapperGetter(appInstanceId,!!legacyRender,strictStyleIsolation,scopedCSS,() => initialAppWrapperElement,);/** generate app wrapper dom getter */
function getAppWrapperGetter(appInstanceId: string,useLegacyRender: boolean,strictStyleIsolation: boolean,scopedCSS: boolean,elementGetter: () => HTMLElement | null,
) {return () => {if (useLegacyRender) {// 省略一些代码...const appWrapper = document.getElementById(getWrapperId(appInstanceId));// 省略一些代码...return appWrapper!;}const element = elementGetter();// 省略一些代码return element!;};
}
兼容。
一些生命周期中需要执行的函数
const {beforeUnmount = [],afterUnmount = [],afterMount = [],beforeMount = [],beforeLoad = [],
} = mergeWith({}, getAddOns(global, assetPublicPath), lifeCycles, (v1, v2) => concat(v1 ?? [], v2 ?? []));
execHooksChain
await execHooksChain(toArray(beforeLoad), app, global)
function execHooksChain<T extends ObjectType>(hooks: Array<LifeCycleFn<T>>,app: LoadableApp<T>,global = window,
): Promise<any> {if (hooks.length) {return hooks.reduce((chain, hook) => chain.then(() => hook(app, global)), Promise.resolve());}return Promise.resolve();
}
微应用加载完成后的返回值
const parcelConfigGetter: ParcelConfigObjectGetter = (remountContainer = initialContainer) => {// 省略相关代码const parcelConfig: ParcelConfigObject = {// 省略相关代码}return parcelConfig;}
parcelConfigGetter返回对象
const parcelConfig: ParcelConfigObject = {name: appInstanceId,bootstrap,mount: [async () => {if (process.env.NODE_ENV === 'development') {const marks = performanceGetEntriesByName(markName, 'mark');// mark length is zero means the app is remountingif (marks && !marks.length) {performanceMark(markName);}}},async () => {if ((await validateSingularMode(singular, app)) && prevAppUnmountedDeferred) {return prevAppUnmountedDeferred.promise;}return undefined;},// initial wrapper element before app mount/remountasync () => {appWrapperElement = initialAppWrapperElement;appWrapperGetter = getAppWrapperGetter(appInstanceId,!!legacyRender,strictStyleIsolation,scopedCSS,() => appWrapperElement,);},// 添加 mount hook, 确保每次应用加载前容器 dom 结构已经设置完毕async () => {const useNewContainer = remountContainer !== initialContainer;if (useNewContainer || !appWrapperElement) {// element will be destroyed after unmounted, we need to recreate it if it not exist// or we try to remount into a new containerappWrapperElement = createElement(appContent, strictStyleIsolation, scopedCSS, appInstanceId);syncAppWrapperElement2Sandbox(appWrapperElement);}render({ element: appWrapperElement, loading: true, container: remountContainer }, 'mounting');},mountSandbox,// exec the chain after rendering to keep the behavior with beforeLoadasync () => execHooksChain(toArray(beforeMount), app, global),async (props) => mount({ ...props, container: appWrapperGetter(), setGlobalState, onGlobalStateChange }),// finish loading after app mountedasync () => render({ element: appWrapperElement, loading: false, container: remountContainer }, 'mounted'),async () => execHooksChain(toArray(afterMount), app, global),// initialize the unmount defer after app mounted and resolve the defer after it unmountedasync () => {if (await validateSingularMode(singular, app)) {prevAppUnmountedDeferred = new Deferred<void>();}},async () => {if (process.env.NODE_ENV === 'development') {const measureName = `[qiankun] App ${appInstanceId} Loading Consuming`;performanceMeasure(measureName, markName);}},],unmount: [async () => execHooksChain(toArray(beforeUnmount), app, global),async (props) => unmount({ ...props, container: appWrapperGetter() }),unmountSandbox,async () => execHooksChain(toArray(afterUnmount), app, global),async () => {render({ element: null, loading: false, container: remountContainer }, 'unmounted');offGlobalStateChange(appInstanceId);// for gcappWrapperElement = null;syncAppWrapperElement2Sandbox(appWrapperElement);},async () => {if ((await validateSingularMode(singular, app)) && prevAppUnmountedDeferred) {prevAppUnmountedDeferred.resolve();}},],};
沙箱容器分析
export function createSandboxContainer(appName: string,elementGetter: () => HTMLElement | ShadowRoot,scopedCSS: boolean,useLooseSandbox?: boolean,excludeAssetFilter?: (url: string) => boolean,globalContext?: typeof window,
) {let sandbox: SandBox;if (window.Proxy) {sandbox = useLooseSandbox ? new LegacySandbox(appName, globalContext) : new ProxySandbox(appName, globalContext);} else {sandbox = new SnapshotSandbox(appName);}// 此处省略许多代码... 占位1
const bootstrappingFreers = patchAtBootstrapping(appName, elementGetter, sandbox, scopedCSS, excludeAssetFilter);
let mountingFreers: Freer[] = [];
let sideEffectsRebuilders: Rebuilder[] = [];return {instance: sandbox,async mount() {// 此处省略许多代码... 占位2sandbox.active();// 此处省略许多代码... 占位3},async unmount() {// 此处省略许多代码... 占位4sandbox.inactive();// 此处省略许多代码... 占位5}};
}
这个对象包含三个属性instace, mount, unmount,其中instace代表沙箱实例,mount,unmount是两个方法,这俩方法使用的是sandbox.active, sandbox.inactive,两个方法让沙箱激活或者失活
patchAtBootstrapping
export function patchAtBootstrapping(appName: string,elementGetter: () => HTMLElement | ShadowRoot,sandbox: SandBox,scopedCSS: boolean,excludeAssetFilter?: CallableFunction,
): Freer[] {const patchersInSandbox = {[SandBoxType.LegacyProxy]: [() => patchLooseSandbox(appName, elementGetter, sandbox.proxy, false, scopedCSS, excludeAssetFilter),],[SandBoxType.Proxy]: [() => patchStrictSandbox(appName, elementGetter, sandbox.proxy, false, scopedCSS, excludeAssetFilter),],[SandBoxType.Snapshot]: [() => patchLooseSandbox(appName, elementGetter, sandbox.proxy, false, scopedCSS, excludeAssetFilter),],};return patchersInSandbox[sandbox.type]?.map((patch) => patch());
}
函数patchAtBootstrapping只做了一件事情,就是根据不同的沙箱类型,执行后并以数组的形式返回执行结果。
函数patchStrictSandbox
export function patchStrictSandbox(appName: string,appWrapperGetter: () => HTMLElement | ShadowRoot,proxy: Window,mounting = true,scopedCSS = false,excludeAssetFilter?: CallableFunction,
): Freer {//*********************第一部分*********************/let containerConfig = proxyAttachContainerConfigMap.get(proxy);if (!containerConfig) {containerConfig = {appName,proxy,appWrapperGetter,dynamicStyleSheetElements: [],strictGlobal: true,excludeAssetFilter,scopedCSS,};proxyAttachContainerConfigMap.set(proxy, containerConfig);}const { dynamicStyleSheetElements } = containerConfig;/***********************第二部分*********************/const unpatchDocumentCreate = patchDocumentCreateElement();const unpatchDynamicAppendPrototypeFunctions = patchHTMLDynamicAppendPrototypeFunctions((element) => elementAttachContainerConfigMap.has(element),(element) => elementAttachContainerConfigMap.get(element)!,);// 此处省略许多代码... return function free() {// 此处省略许多代码... 占位2// 此处省略许多代码...
if (allMicroAppUnmounted) {unpatchDynamicAppendPrototypeFunctions();unpatchDocumentCreate();
}
recordStyledComponentsCSSRules(dynamicStyleSheetElements);return function rebuild() {// 此处省略许多代码... 占位3};};
}
let freeFunc = patchStrictSandbox(许多参数...); // 第一步:在这个函数里面执行了代码,影响了程序状态
let rebuidFun = freeFunc(); // 第二步:将第一步中对程序状态的影响撤销掉
rebuidFun();// 第三步:恢复到第一步执行完成时程序的状态
patchDocumentCreateElement
function patchDocumentCreateElement() {// 省略许多代码...const rawDocumentCreateElement = document.createElement;Document.prototype.createElement = function createElement(// 省略许多代码...): HTMLElement {const element = rawDocumentCreateElement.call(this, tagName, options);// 关键点1if (isHijackingTag(tagName)) {// 省略许多代码}return element;};// 关键点2 if (document.hasOwnProperty('createElement')) {document.createElement = Document.prototype.createElement;}// 关键点3 docCreatePatchedMap.set(Document.prototype.createElement, rawDocumentCreateElement);}return function unpatch() {// 关键点4//此次省略一些代码...Document.prototype.createElement = docCreateElementFnBeforeOverwrite;document.createElement = docCreateElementFnBeforeOverwrite;};
主要是重写document.prototype.createElement
free函数
// 此处省略许多代码...
if (allMicroAppUnmounted) {unpatchDynamicAppendPrototypeFunctions();unpatchDocumentCreate();
}
recordStyledComponentsCSSRules(dynamicStyleSheetElements);
export function recordStyledComponentsCSSRules(styleElements: HTMLStyleElement[]): void {styleElements.forEach((styleElement) => {if (styleElement instanceof HTMLStyleElement && isStyledComponentsLike(styleElement)) {if (styleElement.sheet) {styledComponentCSSRulesMap.set(styleElement, (styleElement.sheet as CSSStyleSheet).cssRules);}}});
}
cssRules代表着一条条具体的css样式,从远程加载而来,对其中的内容进行解析,生成一个style标签。
rebuild
return function rebuild() {rebuildCSSRules(dynamicStyleSheetElements, (stylesheetElement) => {const appWrapper = appWrapperGetter();if (!appWrapper.contains(stylesheetElement)) {rawHeadAppendChild.call(appWrapper, stylesheetElement);return true;}return false;});
};
export function rebuildCSSRules(styleSheetElements: HTMLStyleElement[],reAppendElement: (stylesheetElement: HTMLStyleElement) => boolean,
) {styleSheetElements.forEach((stylesheetElement) => {const appendSuccess = reAppendElement(stylesheetElement);if (appendSuccess) {if (stylesheetElement instanceof HTMLStyleElement && isStyledComponentsLike(stylesheetElement)) {const cssRules = getStyledElementCSSRules(stylesheetElement);if (cssRules) {for (let i = 0; i < cssRules.length; i++) {const cssRule = cssRules[i];const cssStyleSheetElement = stylesheetElement.sheet as CSSStyleSheet;cssStyleSheetElement.insertRule(cssRule.cssText, cssStyleSheetElement.cssRules.length);}}}}});
}
将前面生成的style标签添加到微应用上,将之前保存的cssrule插入到对应的style标签上。
资源加载机制
importEntry
export function importEntry(entry, opts = {}) {const { fetch = defaultFetch, getTemplate = defaultGetTemplate, postProcessTemplate } = opts;const getPublicPath = opts.getPublicPath || opts.getDomain || defaultGetPublicPath;// 省略一些不太关键的代码...if (typeof entry === 'string') {return importHTML(entry, {fetch,getPublicPath,getTemplate,postProcessTemplate,});}// 此处省略了许多代码... 占位1
}
功能
- 加载css/js资源,并且将加载的资源嵌入到html中
- 获取script资源的exports对象
类型
- entry。如果是string,importEntry会调用importHTML执行相关逻辑。会加载styles,scripts对应的资源嵌入到字符串html中,styles对应的style资源的url数组,scripts参数对应的是js资源的url数组,参数html是一个字符串,是一个html页面的具体内容
- ImportEntryOpts: fetch: 自定义加载资源的方法,getPublicPath:自定义资源访问的相关路径。getTemplate: 自定义的html资源预处理的函数。
importHTML
export default function importHTML(url, opts = {}) {// 这里省略许多代码... 占位1
return embedHTMLCache[url] || (embedHTMLCache[url] = fetch(url).then(response => readResAsString(response, autoDecodeResponse)).then(html => {const assetPublicPath = getPublicPath(url);const { template, scripts, entry, styles } = processTpl(getTemplate(html), assetPublicPath, postProcessTemplate);return getEmbedHTML(template, styles, { fetch }).then(embedHTML => ({template: embedHTML,assetPublicPath,getExternalScripts: () => getExternalScripts(scripts, fetch),getExternalStyleSheets: () => getExternalStyleSheets(styles, fetch),execScripts: (proxy, strictGlobal, execScriptsHooks = {}) => {if (!scripts.length) {return Promise.resolve();}return execScripts(entry, scripts, proxy, {fetch,strictGlobal,beforeExec: execScriptsHooks.beforeExec,afterExec: execScriptsHooks.afterExec,});},}));}));
}
- 调用fetch请求html资源
- 调用processTpl处理资源
- 调用getEmbedHTML对processTpl处理后的资源中的链接的远程js,css资源取到本地并嵌入到html中。
processTpl
// 代码片段3,所属文件:src/process-tpl.js
/*匹配整个script标签及其包含的内容,比如 <script>xxxxx</script>或<script xxx>xxxxx</script>[\s\S] 匹配所有字符。\s 是匹配所有空白符,包括换行,\S 非空白符,不包括换行* 匹配前面的子表达式零次或多次+ 匹配前面的子表达式一次或多次正则表达式后面的全局标记 g 指定将该表达式应用到输入字符串中能够查找到的尽可能多的匹配。表达式的结尾处的不区分大小写 i 标记指定不区分大小写。
*/
const ALL_SCRIPT_REGEX = /(<script[\s\S]*?>)[\s\S]*?<\/script>/gi;
/*. 匹配除换行符 \n 之外的任何单字符? 匹配前面的子表达式零次或一次,或指明一个非贪婪限定符。圆括号会有一个副作用,使相关的匹配会被缓存,此时可用 ?: 放在第一个选项前来消除这种副作用。其中 ?: 是非捕获元之一,还有两个非捕获元是 ?= 和 ?!, ?=为正向预查,在任何开始匹配圆括号内的正则表达式模式的位置来匹配搜索字符串,?!为负向预查,在任何开始不匹配该正则表达式模式的位置来匹配搜索字符串。举例:exp1(?!exp2):查找后面不是 exp2 的 exp1。所以这里的真实含义是匹配script标签,但type不能是text/ng-template
*/
const SCRIPT_TAG_REGEX = /<(script)\s+((?!type=('|")text\/ng-template\3).)*?>.*?<\/\1>/is;
/*
* 匹配包含src属性的script标签^ 匹配输入字符串的开始位置,但在方括号表达式中使用时,表示不接受该方括号表达式中的字符集合。
*/
const SCRIPT_SRC_REGEX = /.*\ssrc=('|")?([^>'"\s]+)/;
// 匹配含 type 属性的标签
const SCRIPT_TYPE_REGEX = /.*\stype=('|")?([^>'"\s]+)/;
// 匹配含entry属性的标签//
const SCRIPT_ENTRY_REGEX = /.*\sentry\s*.*/;
// 匹配含 async属性的标签
const SCRIPT_ASYNC_REGEX = /.*\sasync\s*.*/;
// 匹配向后兼容的nomodule标记
const SCRIPT_NO_MODULE_REGEX = /.*\snomodule\s*.*/;
// 匹配含type=module的标签
const SCRIPT_MODULE_REGEX = /.*\stype=('|")?module('|")?\s*.*/;
// 匹配link标签
const LINK_TAG_REGEX = /<(link)\s+.*?>/isg;
// 匹配含 rel=preload或rel=prefetch 的标签, 小提示:rel用于规定当前文档与被了链接文档之间的关系,比如rel=“icon”等
const LINK_PRELOAD_OR_PREFETCH_REGEX = /\srel=('|")?(preload|prefetch)\1/;
// 匹配含href属性的标签
const LINK_HREF_REGEX = /.*\shref=('|")?([^>'"\s]+)/;
// 匹配含as=font的标签
const LINK_AS_FONT = /.*\sas=('|")?font\1.*/;
// 匹配style标签
const STYLE_TAG_REGEX = /<style[^>]*>[\s\S]*?<\/style>/gi;
// 匹配rel=stylesheet的标签
const STYLE_TYPE_REGEX = /\s+rel=('|")?stylesheet\1.*/;
// 匹配含href属性的标签
const STYLE_HREF_REGEX = /.*\shref=('|")?([^>'"\s]+)/;
// 匹配注释
const HTML_COMMENT_REGEX = /<!--([\s\S]*?)-->/g;
// 匹配含ignore属性的 link标签
const LINK_IGNORE_REGEX = /<link(\s+|\s+.+\s+)ignore(\s*|\s+.*|=.*)>/is;
// 匹配含ignore属性的style标签
const STYLE_IGNORE_REGEX = /<style(\s+|\s+.+\s+)ignore(\s*|\s+.*|=.*)>/is;
// 匹配含ignore属性的script标签
const SCRIPT_IGNORE_REGEX = /<script(\s+|\s+.+\s+)ignore(\s*|\s+.*|=.*)>/is;
// 代码片段4,所属文件:src/process-tpl.js
export default function processTpl(tpl, baseURI, postProcessTemplate) {// 这里省略许多代码...let styles = [];const template = tpl.replace(HTML_COMMENT_REGEX, '') // 删掉注释.replace(LINK_TAG_REGEX, match => {// 这里省略许多代码...// 如果link标签中有ignore属性,则替换成占位符`<!-- ignore asset ${ href || 'file'} replaced by import-html-entry -->`// 如果link标签中没有ignore属性,将标签替换成占位符`<!-- ${preloadOrPrefetch ? 'prefetch/preload' : ''} link ${linkHref} replaced by import-html-entry -->`}).replace(STYLE_TAG_REGEX, match => {// 这里省略许多代码...// 如果style标签有ignore属性,则将标签替换成占位符`<!-- ignore asset style file replaced by import-html-entry -->`}).replace(ALL_SCRIPT_REGEX, (match, scriptTag) => {// 这里省略许多代码...// 这里虽然有很多代码,但可以概括为匹配正则表达式,替换成相应的占位符});// 这里省略一些代码...let tplResult = {template,scripts,styles,entry: entry || scripts[scripts.length - 1],};// 这里省略一些代码...return tplResult;
}
getEmbedHTML
function getEmbedHTML(template, styles, opts = {}) {const { fetch = defaultFetch } = opts;let embedHTML = template;return getExternalStyleSheets(styles, fetch).then(styleSheets => {embedHTML = styles.reduce((html, styleSrc, i) => {html = html.replace(genLinkReplaceSymbol(styleSrc), `<style>/* ${styleSrc} */${styleSheets[i]}</style>`);return html;}, embedHTML);return embedHTML;});
}export function getExternalStyleSheets(styles, fetch = defaultFetch) {return Promise.all(styles.map(styleLink => {if (isInlineCode(styleLink)) {// if it is inline stylereturn getInlineCode(styleLink);} else {// external stylesreturn styleCache[styleLink] ||(styleCache[styleLink] = fetch(styleLink).then(response => response.text()));}},));
}
- 获取processTpl中提到style资源链接对应的资源内容
- 将这些资源拼接称为style标签。然后将processTpl中的占位符替换掉
execScripts
export function execScripts(entry, scripts, proxy = window, opts = {}) {// 此处省略许多代码...return getExternalScripts(scripts, fetch, error)// 和获取js资源链接对应的内容.then(scriptsText => {const geval = (scriptSrc, inlineScript) => {// 此处省略许多代码...// 这里主要是把js代码进行一定处理,然后拼装成一个自执行函数,然后用eval执行// 这里最关键的是调用了getExecutableScript,绑定了window.proxy改变js代码中的this引用};function exec(scriptSrc, inlineScript, resolve) {// 这里省略许多代码...// 根据不同的条件,在不同的时机调用geval函数执行js代码,并将入口函数执行完暴露的含有微应用生命周期函数的对象返回// 这里省略许多代码...}function schedule(i, resolvePromise) {// 这里省略许多代码...// 依次调用exec函数执行js资源对应的代码}return new Promise(resolve => schedule(0, success || resolve));});
}
数据通信机制分析
export function registerMicroApps<T extends ObjectType>(apps: Array<RegistrableApp<T>>,lifeCycles?: FrameworkLifeCycles<T>,
) {// 省略许多代码...unregisteredApps.forEach((app) => {const { name, activeRule, loader = noop, props, ...appConfig } = app;registerApplication({name,app: async () => {// 省略许多代码...const { mount, ...otherMicroAppConfigs } = (await loadApp({ name, props, ...appConfig }, frameworkConfiguration, lifeCycles))();// 省略许多代码...},activeWhen: activeRule,customProps: props,});});
}
传入的props参数,在加载微应用的时候直接传入即可,这些参数在微应用执行生命周期方法的时候获取到。
全局事件通信
// 注:为了更容易理解,下面代码和源码中有点出入...
function onGlobalStateChange(callback: OnGlobalStateChangeCallback, fireImmediately?: boolean) {// 该函数主要用于监听事件,将传入的callback函数进行保存
};function setGlobalState(state: Record<string, any> = {}) {// 该函数主要用于更新数据,同时触发全局事件,调用函数onGlobalStateChange保存的对应callback函数
}
触发全局事件
function emitGlobal(state: Record<string, any>, prevState: Record<string, any>) {Object.keys(deps).forEach((id: string) => {if (deps[id] instanceof Function) {deps[id](cloneDeep(state), cloneDeep(prevState));}});
}
sinle-spa中的reroute函数
reroute函数的核心逻辑
export function reroute(pendingPromises = [], eventArguments) {const {appsToUnload,appsToUnmount,appsToLoad,appsToMount,} = getAppChanges();// 此处省略许多代码...if (isStarted()) {// 此处省略一些代码...appsThatChanged = appsToUnload.concat(appsToLoad,appsToUnmount,appsToMount);return performAppChanges();} else {appsThatChanged = appsToLoad;return loadApps();}// 此处省略许多代码...
}
- 通过函数
getAppChanges
获取在single-spa注册过的微应用,并用四个数组变量来区分这些微应用下一步的处理以及状态。 - 根据isStarted()的返回值进行判断,如果调用start函数,则调用performAppChanged函数根据getAppChanges函数的返回值对微应用进行相应的处理,然后改变相应的状态。如果微调用过start函数,则调用loadApp函数执行加载操作
getAppChanges
export function getAppChanges() {const appsToUnload = [],appsToUnmount = [],appsToLoad = [],appsToMount = [];// 此处省略一些代码...apps.forEach((app) => {const appShouldBeActive =app.status !== SKIP_BECAUSE_BROKEN && shouldBeActive(app);switch (app.status) {case LOAD_ERROR:if (appShouldBeActive && currentTime - app.loadErrorTime >= 200) {appsToLoad.push(app);}break;case NOT_LOADED:case LOADING_SOURCE_CODE:if (appShouldBeActive) {appsToLoad.push(app);}break;case NOT_BOOTSTRAPPED:case NOT_MOUNTED:if (!appShouldBeActive && getAppUnloadInfo(toName(app))) {appsToUnload.push(app);} else if (appShouldBeActive) {appsToMount.push(app);}break;case MOUNTED:if (!appShouldBeActive) {appsToUnmount.push(app);}break;}});return { appsToUnload, appsToUnmount, appsToLoad, appsToMount };
}
定义4个数组,然后根据微应用当前所处的不同状态,推断出函数即将要进入的状态,并把即将要进入同一个状态的微应用放到一个相同的数组中。
数组appsToLoad
appsToLoad: NOT_LOADED, LOADING_SOURCE_CODE
appsToLoad数组中存放的微应用在后续的逻辑中即将被加载,在加载中,状态会变化为LOADING_SOURCE_CODE。加载完成之后,状态变成为NOT_BOOTSTRAPPED。
export function toLoadPromise(app) {return Promise.resolve().then(() => {if (app.loadPromise) {return app.loadPromise;}if (app.status !== NOT_LOADED && app.status !== LOAD_ERROR) {return app;}// ...return (app.loadPromise = Promise.resolve().then(() => {// ...delete app.loadPromise;// ...}).catch((err) => {delete app.loadPromise;// ...}));});
}
数组appsToUnload
处于NOT_BOOTSTRAPPED, NOT_MOUNTED状态的微应用,如果不需要处于激活状态且getAppUnloadInfo(toName(app))返回值为true,将微应用加载到appsToUnload中
export function getAppUnloadInfo(appName) {return appsToUnload[appName];
}
appsToUnload是一个全局对象,不是函数getAppChanges中的appsToUnload数组
unloadApplication
文档中的内容,如果希望重新执行bootstrap,可以调用unloadApplication函数是一个不错的选择。一般情况下,是不会轻易卸载微应用的,流程图中MOUNTED -> UNMOUNTING -> UNLOADING -> UNLOADED,如果不是用户手动柑橘,调用unloadApplication,是不会发生的。
toUnloadPromise
appsToUnload
中的微应用即将被执行的主要逻辑都在函数toUnloadPromise中
export function toUnloadPromise(app) {return Promise.resolve().then(() => {const unloadInfo = appsToUnload[toName(app)];// 对象appsToUnload没有值,说明没有调用过unloadApplicaton函数,没必要继续if (!unloadInfo) {return app;}// 说明已经处于NOT_LOADED状态if (app.status === NOT_LOADED) {finishUnloadingApp(app, unloadInfo);return app;}// 已经在卸载中的状态,等执行结果就可以了,注意这里的promise是从对象appsToUnload上面取的if (app.status === UNLOADING) {return unloadInfo.promise.then(() => app);}// 应用的状态转换应该符合流程图所示,只有处于UNMOUNTED状态下的微应用才可以有->UNLOADING->UNLOADED的转化if (app.status !== NOT_MOUNTED && app.status !== LOAD_ERROR) {return app;}const unloadPromise =app.status === LOAD_ERROR? Promise.resolve(): reasonableTime(app, "unload");app.status = UNLOADING;return unloadPromise.then(() => {finishUnloadingApp(app, unloadInfo);return app;}).catch((err) => {errorUnloadingApp(app, unloadInfo, err);return app;});});
}
- 不能符合执行条件的情况进行拦截。
- 利用reasonableTime函数真正的卸载的相关逻辑
- 执行函数finishUnloadingApp或则errorUnloadingApp更改微任务的状态。
resonableTime
export function reasonableTime(appOrParcel, lifecycle) {// 此处省略许多代码...return new Promise((resolve, reject) => {// 此处省略许多代码...appOrParcel[lifecycle](getProps(appOrParcel)).then((val) => {finished = true;resolve(val);}).catch((val) => {finished = true;reject(val);});// 此处省略许多代码...});
}
- 超时处理
- 执行微应用的lifecycle变量对应的函数,在加载阶段让微应用具备了卸载的能力。
appsToMount, appsToUnmount, appsToMount
NOT_BOOTSTRAPPED NOT_MOUNTED状态的微应用,如果和路由规则匹配,则改微应用将会被添加到数组appsToMount。
performAppChanges
function performAppChanges() {return Promise.resolve().then(() => {// 此处省略许多代码...const unloadPromises = appsToUnload.map(toUnloadPromise);const unmountUnloadPromises = appsToUnmount.map(toUnmountPromise).map((unmountPromise) => unmountPromise.then(toUnloadPromise));const allUnmountPromises = unmountUnloadPromises.concat(unloadPromises);const unmountAllPromise = Promise.all(allUnmountPromises);unmountAllPromise.then(() => {// 此处省略许多代码...});// 此处省略许多代码...return unmountAllPromise.catch((err) => {callAllEventListeners();throw err;}).then(() => {callAllEventListeners();// 此处省略许多代码...});});}
- 执行卸载逻辑
- 执行完卸载逻辑后,在执行相关的挂载逻辑
- 在不同阶段派发自定义事件
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