浅谈qiankun微前端
qiankun是single-spa二开；使用场景：不同技术栈，不同团队，独立开发部署、增量升级；总结：解耦；
主应用: 具有整合-输入子应用的html入口；
子应用 与single-spa基本一致，导出了三个生命周期函数 (bootstrap mount unmout)
js沙箱: 三个沙箱（快照沙箱、支持单应用的代理沙箱、多应用代理沙箱）
Snapshot Sandbox 源码解析：里面的iter方法，将遍历window属性的代码抽离出来了，调用这个工具方法后，我们只需要专注于迭代到相应属性时候需要进行的处理。
import type { SandBox } from '../interfaces';
import { SandBoxType } from '../interfaces';
function iter(obj: typeof window, callbackFn: (prop: any) => void) {
// eslint-disable-next-line guard-for-in, no-restricted-syntax
for (const prop in obj) {
// patch for clearInterval for compatible reason, see #1490
if (obj.hasOwnProperty(prop) || prop === 'clearInterval') {
callbackFn(prop);
}
}
}
/**
* 基于 diff 方式实现的沙箱，用于不支持 Proxy 的低版本浏览器
*/
export default class SnapshotSandbox implements SandBox {
proxy: WindowProxy;
name: string;
type: SandBoxType;
sandboxRunning = true;
private windowSnapshot!: Window;
private modifyPropsMap: Record<any, any> = {};
constructor(name: string) {
this.name = name;
this.proxy = window;
this.type = SandBoxType.Snapshot;
}
active() {
// 记录当前快照
this.windowSnapshot = {} as Window;
iter(window, (prop) => {
this.windowSnapshot[prop] = window[prop];
});
// 恢复之前的变更
Object.keys(this.modifyPropsMap).forEach((p: any) => {
window[p] = this.modifyPropsMap[p];
});
this.sandboxRunning = true;
}
inactive() {
this.modifyPropsMap = {};
iter(window, (prop) => {
if (window[prop] !== this.windowSnapshot[prop]) {
// 记录变更，恢复环境
this.modifyPropsMap[prop] = window[prop];
window[prop] = this.windowSnapshot[prop];
}
});
if (process.env.NODE_ENV === 'development') {
console.info(`[qiankun:sandbox] ${this.name} origin window restore...`, Object.keys(this.modifyPropsMap));
}
this.sandboxRunning = false;
}
}
LegacySandbox 过三个变量来记住沙箱激活后window发生变化过的所有属性，这样在后续的状态还原时候就不再需要遍历window的所有属性来进行对比，提升了程序运行的性能。但是这仍然改变不了这种机制仍然污染了window的状态的事实，因此也就无法承担起同时支持多个微应用运行的任务。
import type { SandBox } from '../../interfaces';
import { SandBoxType } from '../../interfaces';
import { getTargetValue } from '../common';
function isPropConfigurable(target: WindowProxy, prop: PropertyKey) {
const descriptor = Object.getOwnPropertyDescriptor(target, prop);
return descriptor ? descriptor.configurable : true;
}
/**
* 基于 Proxy 实现的沙箱
* TODO: 为了兼容性 singular 模式下依旧使用该沙箱，等新沙箱稳定之后再切换
*/
export default class LegacySandbox implements SandBox {
/** 沙箱期间新增的全局变量 */
private addedPropsMapInSandbox = new Map<PropertyKey, any>();
/** 沙箱期间更新的全局变量 */
private modifiedPropsOriginalValueMapInSandbox = new Map<PropertyKey, any>();
/** 持续记录更新的(新增和修改的)全局变量的 map，用于在任意时刻做 snapshot */
private currentUpdatedPropsValueMap = new Map<PropertyKey, any>();
name: string;
proxy: WindowProxy;
globalContext: typeof window;
type: SandBoxType;
sandboxRunning = true;
latestSetProp: PropertyKey | null = null;
private setWindowProp(prop: PropertyKey, value: any, toDelete?: boolean) {
if (value === undefined && toDelete) {
// eslint-disable-next-line no-param-reassign
delete (this.globalContext as any)[prop];
} else if (isPropConfigurable(this.globalContext, prop) && typeof prop !== 'symbol') {
Object.defineProperty(this.globalContext, prop, { writable: true, configurable: true });
// eslint-disable-next-line no-param-reassign
(this.globalContext as any)[prop] = value;
}
}
active() {
if (!this.sandboxRunning) {
this.currentUpdatedPropsValueMap.forEach((v, p) => this.setWindowProp(p, v));
}
this.sandboxRunning = true;
}
inactive() {
if (process.env.NODE_ENV === 'development') {
console.info(`[qiankun:sandbox] ${this.name} modified global properties restore...`, [
...this.addedPropsMapInSandbox.keys(),
...this.modifiedPropsOriginalValueMapInSandbox.keys(),
]);
}
// renderSandboxSnapshot = snapshot(currentUpdatedPropsValueMapForSnapshot);
// restore global props to initial snapshot
this.modifiedPropsOriginalValueMapInSandbox.forEach((v, p) => this.setWindowProp(p, v));
this.addedPropsMapInSandbox.forEach((_, p) => this.setWindowProp(p, undefined, true));
this.sandboxRunning = false;
}
constructor(name: string, globalContext = window) {
this.name = name;
this.globalContext = globalContext;
this.type = SandBoxType.LegacyProxy;
const { addedPropsMapInSandbox, modifiedPropsOriginalValueMapInSandbox, currentUpdatedPropsValueMap } = this;
const rawWindow = globalContext;
const fakeWindow = Object.create(null) as Window;
const setTrap = (p: PropertyKey, value: any, originalValue: any, sync2Window = true) => {
if (this.sandboxRunning) {
if (!rawWindow.hasOwnProperty(p)) {
addedPropsMapInSandbox.set(p, value);
} else if (!modifiedPropsOriginalValueMapInSandbox.has(p)) {
// 如果当前 window 对象存在该属性，且 record map 中未记录过，则记录该属性初始值
modifiedPropsOriginalValueMapInSandbox.set(p, originalValue);
}
currentUpdatedPropsValueMap.set(p, value);
if (sync2Window) {
// 必须重新设置 window 对象保证下次 get 时能拿到已更新的数据
(rawWindow as any)[p] = value;
}
this.latestSetProp = p;
return true;
}
if (process.env.NODE_ENV === 'development') {
console.warn(`[qiankun] Set window.${p.toString()} while sandbox destroyed or inactive in ${name}!`);
}
// 在 strict-mode 下，Proxy 的 handler.set 返回 false 会抛出 TypeError，在沙箱卸载的情况下应该忽略错误
return true;
};
const proxy = new Proxy(fakeWindow, {
set: (_: Window, p: PropertyKey, value: any): boolean => {
const originalValue = (rawWindow as any)[p];
return setTrap(p, value, originalValue, true);
},
get(_: Window, p: PropertyKey): any {
// avoid who using window.window or window.self to escape the sandbox environment to touch the really window
// or use window.top to check if an iframe context
// see https://github.com/eligrey/FileSaver.js/blob/master/src/FileSaver.js#L13
if (p === 'top' || p === 'parent' || p === 'window' || p === 'self') {
return proxy;
}
const value = (rawWindow as any)[p];
return getTargetValue(rawWindow, value);
},
// trap in operator
// see https://github.com/styled-components/styled-components/blob/master/packages/styled-components/src/constants.js#L12
has(_: Window, p: string | number | symbol): boolean {
return p in rawWindow;
},
getOwnPropertyDescriptor(_: Window, p: PropertyKey): PropertyDescriptor | undefined {
const descriptor = Object.getOwnPropertyDescriptor(rawWindow, p);
// A property cannot be reported as non-configurable, if it does not exists as an own property of the target object
if (descriptor && !descriptor.configurable) {
descriptor.configurable = true;
}
return descriptor;
},
defineProperty(_: Window, p: string | symbol, attributes: PropertyDescriptor): boolean {
const originalValue = (rawWindow as any)[p];
const done = Reflect.defineProperty(rawWindow, p, attributes);
const value = (rawWindow as any)[p];
setTrap(p, value, originalValue, false);
return done;
},
});
this.proxy = proxy;
}
}
ProxySandbox 源码解析:它将window上的所有属性遍历拷贝生成一个新的fakeWindow对象，紧接着使用proxy代理这个fakeWindow，用户对window操作全部被拦截下来，只作用于在这个fakeWindow之上
import type { SandBox } from '../interfaces';
import { SandBoxType } from '../interfaces';
import { nativeGlobal, nextTask } from '../utils';
import { getTargetValue, setCurrentRunningApp, getCurrentRunningApp } from './common';
type SymbolTarget = 'target' | 'globalContext';
type FakeWindow = Window & Record<PropertyKey, any>;
/**
* fastest(at most time) unique array method
* @see https://jsperf.com/array-filter-unique/30
*/
function uniq(array: Array<string | symbol>) {
return array.filter(function filter(this: PropertyKey[], element) {
return element in this ? false : ((this as any)[element] = true);
}, Object.create(null));
}
// zone.js will overwrite Object.defineProperty
const rawObjectDefineProperty = Object.defineProperty;
const variableWhiteListInDev =
process.env.NODE_ENV === 'development' || window.__QIANKUN_DEVELOPMENT__
? [
// for react hot reload
// see https://github.com/facebook/create-react-app/blob/66bf7dfc43350249e2f09d138a20840dae8a0a4a/packages/react-error-overlay/src/index.js#L180
'__REACT_ERROR_OVERLAY_GLOBAL_HOOK__',
]
: [];
// who could escape the sandbox
const variableWhiteList: PropertyKey[] = [
// FIXME System.js used a indirect call with eval, which would make it scope escape to global
// To make System.js works well, we write it back to global window temporary
// see https://github.com/systemjs/systemjs/blob/457f5b7e8af6bd120a279540477552a07d5de086/src/evaluate.js#L106
'System',
// see https://github.com/systemjs/systemjs/blob/457f5b7e8af6bd120a279540477552a07d5de086/src/instantiate.js#L357
'__cjsWrapper',
...variableWhiteListInDev,
];
/*
variables who are impossible to be overwrite need to be escaped from proxy sandbox for performance reasons
*/
const unscopables = {
undefined: true,
Array: true,
Object: true,
String: true,
Boolean: true,
Math: true,
Number: true,
Symbol: true,
parseFloat: true,
Float32Array: true,
isNaN: true,
Infinity: true,
Reflect: true,
Float64Array: true,
Function: true,
Map: true,
NaN: true,
Promise: true,
Proxy: true,
Set: true,
parseInt: true,
requestAnimationFrame: true,
};
const useNativeWindowForBindingsProps = new Map<PropertyKey, boolean>([
['fetch', true],
['mockDomAPIInBlackList', process.env.NODE_ENV === 'test'],
]);
function createFakeWindow(globalContext: Window) {
// map always has the fastest performance in has check scenario
// see https://jsperf.com/array-indexof-vs-set-has/23
const propertiesWithGetter = new Map<PropertyKey, boolean>();
const fakeWindow = {} as FakeWindow;
/*
copy the non-configurable property of global to fakeWindow
see https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Proxy/handler/getOwnPropertyDescriptor
> A property cannot be reported as non-configurable, if it does not exists as an own property of the target object or if it exists as a configurable own property of the target object.
*/
Object.getOwnPropertyNames(globalContext)
.filter((p) => {
const descriptor = Object.getOwnPropertyDescriptor(globalContext, p);
return !descriptor?.configurable;
})
.forEach((p) => {
const descriptor = Object.getOwnPropertyDescriptor(globalContext, p);
if (descriptor) {
const hasGetter = Object.prototype.hasOwnProperty.call(descriptor, 'get');
/*
make top/self/window property configurable and writable, otherwise it will cause TypeError while get trap return.
see https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Proxy/handler/get
> The value reported for a property must be the same as the value of the corresponding target object property if the target object property is a non-writable, non-configurable data property.
*/
if (
p === 'top' ||
p === 'parent' ||
p === 'self' ||
p === 'window' ||
(process.env.NODE_ENV === 'test' && (p === 'mockTop' || p === 'mockSafariTop'))
) {
descriptor.configurable = true;
/*
The descriptor of window.window/window.top/window.self in Safari/FF are accessor descriptors, we need to avoid adding a data descriptor while it was
Example:
Safari/FF: Object.getOwnPropertyDescriptor(window, 'top') -> {get: function, set: undefined, enumerable: true, configurable: false}
Chrome: Object.getOwnPropertyDescriptor(window, 'top') -> {value: Window, writable: false, enumerable: true, configurable: false}
*/
if (!hasGetter) {
descriptor.writable = true;
}
}
if (hasGetter) propertiesWithGetter.set(p, true);
// freeze the descriptor to avoid being modified by zone.js
// see https://github.com/angular/zone.js/blob/a5fe09b0fac27ac5df1fa746042f96f05ccb6a00/lib/browser/define-property.ts#L71
rawObjectDefineProperty(fakeWindow, p, Object.freeze(descriptor));
}
});
return {
fakeWindow,
propertiesWithGetter,
};
}
let activeSandboxCount = 0;
/**
* 基于 Proxy 实现的沙箱
*/
export default class ProxySandbox implements SandBox {
/** window 值变更记录 */
private updatedValueSet = new Set<PropertyKey>();
name: string;
type: SandBoxType;
proxy: WindowProxy;
globalContext: typeof window;
sandboxRunning = true;
latestSetProp: PropertyKey | null = null;
private registerRunningApp(name: string, proxy: Window) {
if (this.sandboxRunning) {
const currentRunningApp = getCurrentRunningApp();
if (!currentRunningApp || currentRunningApp.name !== name) {
setCurrentRunningApp({ name, window: proxy });
}
// FIXME if you have any other good ideas
// remove the mark in next tick, thus we can identify whether it in micro app or not
// this approach is just a workaround, it could not cover all complex cases, such as the micro app runs in the same task context with master in some case
nextTask(() => {
setCurrentRunningApp(null);
});
}
}
active() {
if (!this.sandboxRunning) activeSandboxCount++;
this.sandboxRunning = true;
}
inactive() {
if (process.env.NODE_ENV === 'development') {
console.info(`[qiankun:sandbox] ${this.name} modified global properties restore...`, [
...this.updatedValueSet.keys(),
]);
}
if (--activeSandboxCount === 0) {
variableWhiteList.forEach((p) => {
if (this.proxy.hasOwnProperty(p)) {
// @ts-ignore
delete this.globalContext[p];
}
});
}
this.sandboxRunning = false;
}
constructor(name: string, globalContext = window) {
this.name = name;
this.globalContext = globalContext;
this.type = SandBoxType.Proxy;
const { updatedValueSet } = this;
const { fakeWindow, propertiesWithGetter } = createFakeWindow(globalContext);
const descriptorTargetMap = new Map<PropertyKey, SymbolTarget>();
const hasOwnProperty = (key: PropertyKey) => fakeWindow.hasOwnProperty(key) || globalContext.hasOwnProperty(key);
const proxy = new Proxy(fakeWindow, {
set: (target: FakeWindow, p: PropertyKey, value: any): boolean => {
if (this.sandboxRunning) {
this.registerRunningApp(name, proxy);
// We must kept its description while the property existed in globalContext before
if (!target.hasOwnProperty(p) && globalContext.hasOwnProperty(p)) {
const descriptor = Object.getOwnPropertyDescriptor(globalContext, p);
const { writable, configurable, enumerable } = descriptor!;
if (writable) {
Object.defineProperty(target, p, {
configurable,
enumerable,
writable,
value,
});
}
} else {
// @ts-ignore
target[p] = value;
}
if (variableWhiteList.indexOf(p) !== -1) {
// @ts-ignore
globalContext[p] = value;
}
updatedValueSet.add(p);
this.latestSetProp = p;
return true;
}
if (process.env.NODE_ENV === 'development') {
console.warn(`[qiankun] Set window.${p.toString()} while sandbox destroyed or inactive in ${name}!`);
}
// 在 strict-mode 下，Proxy 的 handler.set 返回 false 会抛出 TypeError，在沙箱卸载的情况下应该忽略错误
return true;
},
get: (target: FakeWindow, p: PropertyKey): any => {
this.registerRunningApp(name, proxy);
if (p === Symbol.unscopables) return unscopables;
// avoid who using window.window or window.self to escape the sandbox environment to touch the really window
// see https://github.com/eligrey/FileSaver.js/blob/master/src/FileSaver.js#L13
if (p === 'window' || p === 'self') {
return proxy;
}
// hijack globalWindow accessing with globalThis keyword
if (p === 'globalThis') {
return proxy;
}
if (
p === 'top' ||
p === 'parent' ||
(process.env.NODE_ENV === 'test' && (p === 'mockTop' || p === 'mockSafariTop'))
) {
// if your master app in an iframe context, allow these props escape the sandbox
if (globalContext === globalContext.parent) {
return proxy;
}
return (globalContext as any)[p];
}
// proxy.hasOwnProperty would invoke getter firstly, then its value represented as globalContext.hasOwnProperty
if (p === 'hasOwnProperty') {
return hasOwnProperty;
}
if (p === 'document') {
return document;
}
if (p === 'eval') {
return eval;
}
const value = propertiesWithGetter.has(p)
? (globalContext as any)[p]
: p in target
? (target as any)[p]
: (globalContext as any)[p];
/* Some dom api must be bound to native window, otherwise it would cause exception like 'TypeError: Failed to execute 'fetch' on 'Window': Illegal invocation'
See this code:
const proxy = new Proxy(window, {});
const proxyFetch = fetch.bind(proxy);
proxyFetch('https://qiankun.com');
*/
const boundTarget = useNativeWindowForBindingsProps.get(p) ? nativeGlobal : globalContext;
return getTargetValue(boundTarget, value);
},
// trap in operator
// see https://github.com/styled-components/styled-components/blob/master/packages/styled-components/src/constants.js#L12
has(target: FakeWindow, p: string | number | symbol): boolean {
return p in unscopables || p in target || p in globalContext;
},
getOwnPropertyDescriptor(target: FakeWindow, p: string | number | symbol): PropertyDescriptor | undefined {
/*
as the descriptor of top/self/window/mockTop in raw window are configurable but not in proxy target, we need to get it from target to avoid TypeError
see https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Proxy/handler/getOwnPropertyDescriptor
> A property cannot be reported as non-configurable, if it does not exists as an own property of the target object or if it exists as a configurable own property of the target object.
*/
if (target.hasOwnProperty(p)) {
const descriptor = Object.getOwnPropertyDescriptor(target, p);
descriptorTargetMap.set(p, 'target');
return descriptor;
}
if (globalContext.hasOwnProperty(p)) {
const descriptor = Object.getOwnPropertyDescriptor(globalContext, p);
descriptorTargetMap.set(p, 'globalContext');
// A property cannot be reported as non-configurable, if it does not exists as an own property of the target object
if (descriptor && !descriptor.configurable) {
descriptor.configurable = true;
}
return descriptor;
}
return undefined;
},
// trap to support iterator with sandbox
ownKeys(target: FakeWindow): ArrayLike<string | symbol> {
return uniq(Reflect.ownKeys(globalContext).concat(Reflect.ownKeys(target)));
},
defineProperty(target: Window, p: PropertyKey, attributes: PropertyDescriptor): boolean {
const from = descriptorTargetMap.get(p);
/*
Descriptor must be defined to native window while it comes from native window via Object.getOwnPropertyDescriptor(window, p),
otherwise it would cause a TypeError with illegal invocation.
*/
switch (from) {
case 'globalContext':
return Reflect.defineProperty(globalContext, p, attributes);
default:
return Reflect.defineProperty(target, p, attributes);
}
},
deleteProperty: (target: FakeWindow, p: string | number | symbol): boolean => {
this.registerRunningApp(name, proxy);
if (target.hasOwnProperty(p)) {
// @ts-ignore
delete target[p];
updatedValueSet.delete(p);
return true;
}
return true;
},
// makes sure `window instanceof Window` returns truthy in micro app
getPrototypeOf() {
return Reflect.getPrototypeOf(globalContext);
},
});
this.proxy = proxy;
activeSandboxCount++;
}
}
css隔离 有2种方案，一种是基于shadowDom;（缺陷：样式弹窗脱离shadow tree会污染） 一种类似vue 的scoped给每一个子应用加一个约束；
预加载
html entry 通过http请求加载制定地址的首屏内容html，解析-template script entry styles 暴漏一个promise对象
{ // template 是link替换为style之后的template template: embedHTML, // 静态资源文件 assetPublicPath， // 获取外部脚本 getExternalScripts: () => getExternalScripts(scripts, fetch), // 获取外部样式文件 getExternalStyleSheets: () => getExternalStylesSheets(styles, fetch), // 脚本执行器, 让js代码在指定上下文中运行 execScripts: (proxy, strictGlobal) => { if(!scripts.length){ return Promise.resolve() } return execScripts(entry, scripts, proxy, {fetch, strictGlobal}) } }
js entry 加载的不是应用本身，是js导出文件，并且含有生命周期；
应用通讯
主基座创建全局的globalState对象，修改值变化方法：setGlobalState 监听值变化：onGlobalStateChange
// ------------------主应用------------------ import { initGlobalState, MicroAppStateActions } from 'qiankun'; // 初始化 state const actions: MicroAppStateActions = initGlobalState(state); // 在当前应用监听全局状态，有变更触发 callback actions.onGlobalStateChange((state, prev) => { // state: 变更后的状态; prev 变更前的状态 console.log(state, prev); }); // 按一级属性设置全局状态，微应用中只能修改已存在的一级属性 actions.setGlobalState(state); // 移除当前应用的状态监听，微应用 umount 时会默认调用 actions.offGlobalStateChange(); // ------------------子应用------------------ // 从生命周期 mount 中获取通信方法，使用方式和 master 一致 export function mount(props) { props.onGlobalStateChange((state, prev) => { // state: 变更后的状态; prev 变更前的状态 console.log(state, prev); }); props.setGlobalState(state); }
源码解析：initGlobalState函数的执行中完成了一个发布订阅模式的创建工作，并返回了相关的订阅/发布/注销方法
import { cloneDeep } from 'lodash';
import type { OnGlobalStateChangeCallback, MicroAppStateActions } from './interfaces';
// 全局状态
let globalState: Record<string, any> = {};
// 缓存相关的订阅者
const deps: Record<string, OnGlobalStateChangeCallback> = {};
// 触发全局监听
function emitGlobal(state: Record<string, any>, prevState: Record<string, any>) {
Object.keys(deps).forEach((id: string) => {
if (deps[id] instanceof Function) {
// 依次通知订阅者
deps[id](cloneDeep(state), cloneDeep(prevState));
}
});
}
// 初始化
export function initGlobalState(state: Record<string, any> = {}) {
if (state === globalState) {
console.warn('[qiankun] state has not changed！');
} else {
const prevGlobalState = cloneDeep(globalState);
globalState = cloneDeep(state);
emitGlobal(globalState, prevGlobalState);
}
// 返回相关方法，形成闭包存储相关状态
return getMicroAppStateActions(`global-${+new Date()}`, true);
}
export function getMicroAppStateActions(id: string, isMaster?: boolean): MicroAppStateActions {
return {
/**
* onGlobalStateChange 全局依赖监听
*
* 收集 setState 时所需要触发的依赖
*
* 限制条件：每个子应用只有一个激活状态的全局监听，新监听覆盖旧监听，若只是监听部分属性，请使用 onGlobalStateChange
*
* 这么设计是为了减少全局监听滥用导致的内存爆炸
*
* 依赖数据结构为：
* {
* {id}: callback
* }
*
* @param callback
* @param fireImmediately 是否立即执行callback
*/
onGlobalStateChange(callback: OnGlobalStateChangeCallback, fireImmediately?: boolean) {
if (!(callback instanceof Function)) {
console.error('[qiankun] callback must be function!');
return;
}
if (deps[id]) {
console.warn(`[qiankun] '${id}' global listener already exists before this, new listener will overwrite it.`);
}
/ 注册订阅
deps[id] = callback;
if (fireImmediately) {
const cloneState = cloneDeep(globalState);
callback(cloneState, cloneState);
}
},
/**
* setGlobalState 更新 store 数据
*
* 1. 对输入 state 的第一层属性做校验，只有初始化时声明过的第一层（bucket）属性才会被更改
* 2. 修改 store 并触发全局监听
*
* @param state
*/
setGlobalState(state: Record<string, any> = {}) {
if (state === globalState) {
console.warn('[qiankun] state has not changed！');
return false;
}
const changeKeys: string[] = [];
const prevGlobalState = cloneDeep(globalState);
globalState = cloneDeep(
Object.keys(state).reduce((_globalState, changeKey) => {
if (isMaster || _globalState.hasOwnProperty(changeKey)) {
changeKeys.push(changeKey);
return Object.assign(_globalState, { [changeKey]: state[changeKey] });
}
console.warn(`[qiankun] '${changeKey}' not declared when init state！`);
return _globalState;
}, globalState),
);
if (changeKeys.length === 0) {
console.warn('[qiankun] state has not changed！');
return false;
}
// 触发全局监听
emitGlobal(globalState, prevGlobalState);
return true;
},
// 注销该应用下的依赖
offGlobalStateChange() {
delete deps[id];
return true;
},
};
}
iframe那不行？
1.url不同步，浏览器刷新iframe url 状态丢失、后退前进按钮无法使用；
2.全文上下文完全隔离，内存变量不共享；iframe 内外系统的通信、数据同步等需求，主应用的 cookie 要透传到根域名都不同的子应用中实现免登效果。
3.慢。每次子应用进入都是一次浏览器上下文重建、资源重新加载的过程。
