我有一个 Angular 2 模块，我在其中实现了路由，并希望在导航时存储状态。
用户应该能够：
- 使用“搜索公式”搜索文档
- 导航到其中一个结果
- 导航回“搜索结果” - 不与服务器通信
这是可能的，包括RouteReuseStrategy.
问题是：
如何实现不应该存储文档？
所以应该存储路由路径“documents”的状态，而不应该存储路由路径“documents/:id”的状态？
问问题
71085 次
10 回答
269
嘿安德斯，好问题！
我有几乎和你一样的用例，并且想做同样的事情！用户搜索 > 获取结果 > 用户导航到结果 > 用户导航返回 > BOOM 快速返回结果，但您不想存储用户导航到的特定结果。
tl;博士
您需要有一个类来实现RouteReuseStrategy并在ngModule. 如果要修改路由存储的时间，修改shouldDetach函数即可。当它返回时true，Angular 会存储路由。如果要在附加路由时进行修改，请修改shouldAttach函数。当shouldAttach返回 true 时，Angular 将使用存储的路由来代替请求的路由。这是一个Plunker供您玩耍。
关于RouteReuseStrategy
通过提出这个问题，您已经了解 RouteReuseStrategy 允许您告诉 Angular不要销毁组件，而是将其保存以供以后重新渲染。这很酷，因为它允许：
- 减少服务器调用
- 提高速度
- 并且默认情况下，组件呈现与离开时相同的状态
如果您想暂时离开一个页面，即使用户在其中输入了很多文本，最后一个也很重要。由于表单数量过多，企业应用程序会喜欢此功能！
这就是我想出的解决问题的方法。正如您所说，您需要使用RouteReuseStrategy@angular/router 在 3.4.1 及更高版本中提供的功能。
去做
首先确保您的项目具有@angular/router 3.4.1 或更高版本。
接下来，创建一个文件，该文件将容纳您实现的类RouteReuseStrategy。我打电话给我reuse-strategy.ts的，把它放在/app文件夹里妥善保管。现在，这个类应该是这样的：
import { RouteReuseStrategy } from '@angular/router';
export class CustomReuseStrategy implements RouteReuseStrategy {
}
（不用担心您的 TypeScript 错误，我们将解决所有问题）
通过向您的app.module. 请注意，您还没有写CustomReuseStrategy，但应该继续和import它从reuse-strategy.ts都一样。还import { RouteReuseStrategy } from '@angular/router';
@NgModule({
[...],
providers: [
{provide: RouteReuseStrategy, useClass: CustomReuseStrategy}
]
)}
export class AppModule {
}
最后一部分是编写将控制路由是否被分离、存储、检索和重新附加的类。在我们进入旧的复制/粘贴之前，我将在这里对机制做一个简短的解释，因为我理解它们。参考下面的代码了解我所描述的方法，当然，代码中有大量的文档。
- 当您导航时，
shouldReuseRoute会触发。这对我来说有点奇怪，但如果它返回true，那么它实际上会重用您当前所在的路线，并且不会触发任何其他方法。如果用户正在导航，我只会返回 false。 - 如果
shouldReuseRoute返回false，则shouldDetach触发。shouldDetach确定是否要存储路线，并返回一个boolean指示。这是您应该决定存储/不存储路径的地方，我会通过检查要存储的路径数组来完成，如果数组中不存在route.routeConfig.path则返回 false 。path - 如果
shouldDetach返回true，store则被触发，这是您存储您想要的有关路线的任何信息的机会。无论你做什么，你都需要存储 ，DetachedRouteHandle因为这是 Angular 以后用来识别你存储的组件的。下面，我将 theDetachedRouteHandle和 the都存储ActivatedRouteSnapshot到我的班级的本地变量中。
所以，我们已经看到了存储的逻辑，但是导航到一个组件呢？Angular 是如何决定拦截您的导航并将存储的导航放置在原位的？
- 同样，在
shouldReuseRoute返回之后false，shouldAttach运行，这是您确定是否要重新生成或使用内存中的组件的机会。如果您想重复使用存储的组件，请返回true，然后您就可以顺利进行了！ - 现在 Angular 会问你，“你希望我们使用哪个组件？”，你将通过返回该组件的
DetachedRouteHandlefrom 来表示retrieve。
这几乎就是您需要的所有逻辑！在下面的代码reuse-strategy.ts中，我还为您留下了一个漂亮的函数，它将比较两个对象。我用它来比较未来的路线route.params和route.queryParams存储的路线。如果这些都匹配，我想使用存储的组件而不是生成一个新的。但如何做取决于你！
重用策略.ts
/**
* reuse-strategy.ts
* by corbfon 1/6/17
*/
import { ActivatedRouteSnapshot, RouteReuseStrategy, DetachedRouteHandle } from '@angular/router';
/** Interface for object which can store both:
* An ActivatedRouteSnapshot, which is useful for determining whether or not you should attach a route (see this.shouldAttach)
* A DetachedRouteHandle, which is offered up by this.retrieve, in the case that you do want to attach the stored route
*/
interface RouteStorageObject {
snapshot: ActivatedRouteSnapshot;
handle: DetachedRouteHandle;
}
export class CustomReuseStrategy implements RouteReuseStrategy {
/**
* Object which will store RouteStorageObjects indexed by keys
* The keys will all be a path (as in route.routeConfig.path)
* This allows us to see if we've got a route stored for the requested path
*/
storedRoutes: { [key: string]: RouteStorageObject } = {};
/**
* Decides when the route should be stored
* If the route should be stored, I believe the boolean is indicating to a controller whether or not to fire this.store
* _When_ it is called though does not particularly matter, just know that this determines whether or not we store the route
* An idea of what to do here: check the route.routeConfig.path to see if it is a path you would like to store
* @param route This is, at least as I understand it, the route that the user is currently on, and we would like to know if we want to store it
* @returns boolean indicating that we want to (true) or do not want to (false) store that route
*/
shouldDetach(route: ActivatedRouteSnapshot): boolean {
let detach: boolean = true;
console.log("detaching", route, "return: ", detach);
return detach;
}
/**
* Constructs object of type `RouteStorageObject` to store, and then stores it for later attachment
* @param route This is stored for later comparison to requested routes, see `this.shouldAttach`
* @param handle Later to be retrieved by this.retrieve, and offered up to whatever controller is using this class
*/
store(route: ActivatedRouteSnapshot, handle: DetachedRouteHandle): void {
let storedRoute: RouteStorageObject = {
snapshot: route,
handle: handle
};
console.log( "store:", storedRoute, "into: ", this.storedRoutes );
// routes are stored by path - the key is the path name, and the handle is stored under it so that you can only ever have one object stored for a single path
this.storedRoutes[route.routeConfig.path] = storedRoute;
}
/**
* Determines whether or not there is a stored route and, if there is, whether or not it should be rendered in place of requested route
* @param route The route the user requested
* @returns boolean indicating whether or not to render the stored route
*/
shouldAttach(route: ActivatedRouteSnapshot): boolean {
// this will be true if the route has been stored before
let canAttach: boolean = !!route.routeConfig && !!this.storedRoutes[route.routeConfig.path];
// this decides whether the route already stored should be rendered in place of the requested route, and is the return value
// at this point we already know that the paths match because the storedResults key is the route.routeConfig.path
// so, if the route.params and route.queryParams also match, then we should reuse the component
if (canAttach) {
let willAttach: boolean = true;
console.log("param comparison:");
console.log(this.compareObjects(route.params, this.storedRoutes[route.routeConfig.path].snapshot.params));
console.log("query param comparison");
console.log(this.compareObjects(route.queryParams, this.storedRoutes[route.routeConfig.path].snapshot.queryParams));
let paramsMatch: boolean = this.compareObjects(route.params, this.storedRoutes[route.routeConfig.path].snapshot.params);
let queryParamsMatch: boolean = this.compareObjects(route.queryParams, this.storedRoutes[route.routeConfig.path].snapshot.queryParams);
console.log("deciding to attach...", route, "does it match?", this.storedRoutes[route.routeConfig.path].snapshot, "return: ", paramsMatch && queryParamsMatch);
return paramsMatch && queryParamsMatch;
} else {
return false;
}
}
/**
* Finds the locally stored instance of the requested route, if it exists, and returns it
* @param route New route the user has requested
* @returns DetachedRouteHandle object which can be used to render the component
*/
retrieve(route: ActivatedRouteSnapshot): DetachedRouteHandle {
// return null if the path does not have a routerConfig OR if there is no stored route for that routerConfig
if (!route.routeConfig || !this.storedRoutes[route.routeConfig.path]) return null;
console.log("retrieving", "return: ", this.storedRoutes[route.routeConfig.path]);
/** returns handle when the route.routeConfig.path is already stored */
return this.storedRoutes[route.routeConfig.path].handle;
}
/**
* Determines whether or not the current route should be reused
* @param future The route the user is going to, as triggered by the router
* @param curr The route the user is currently on
* @returns boolean basically indicating true if the user intends to leave the current route
*/
shouldReuseRoute(future: ActivatedRouteSnapshot, curr: ActivatedRouteSnapshot): boolean {
console.log("deciding to reuse", "future", future.routeConfig, "current", curr.routeConfig, "return: ", future.routeConfig === curr.routeConfig);
return future.routeConfig === curr.routeConfig;
}
/**
* This nasty bugger finds out whether the objects are _traditionally_ equal to each other, like you might assume someone else would have put this function in vanilla JS already
* One thing to note is that it uses coercive comparison (==) on properties which both objects have, not strict comparison (===)
* Another important note is that the method only tells you if `compare` has all equal parameters to `base`, not the other way around
* @param base The base object which you would like to compare another object to
* @param compare The object to compare to base
* @returns boolean indicating whether or not the objects have all the same properties and those properties are ==
*/
private compareObjects(base: any, compare: any): boolean {
// loop through all properties in base object
for (let baseProperty in base) {
// determine if comparrison object has that property, if not: return false
if (compare.hasOwnProperty(baseProperty)) {
switch(typeof base[baseProperty]) {
// if one is object and other is not: return false
// if they are both objects, recursively call this comparison function
case 'object':
if ( typeof compare[baseProperty] !== 'object' || !this.compareObjects(base[baseProperty], compare[baseProperty]) ) { return false; } break;
// if one is function and other is not: return false
// if both are functions, compare function.toString() results
case 'function':
if ( typeof compare[baseProperty] !== 'function' || base[baseProperty].toString() !== compare[baseProperty].toString() ) { return false; } break;
// otherwise, see if they are equal using coercive comparison
default:
if ( base[baseProperty] != compare[baseProperty] ) { return false; }
}
} else {
return false;
}
}
// returns true only after false HAS NOT BEEN returned through all loops
return true;
}
}
行为
此实现将用户在路由器上访问的每条唯一路由仅存储一次。这将在整个用户在站点上的会话期间继续添加到存储在内存中的组件。如果你想限制你存储的路线，那么做的地方就是shouldDetach方法。它控制您保存的路线。
例子
假设您的用户从主页搜索某些内容，该主页会将他们导航到路径search/:term，该路径可能看起来像www.yourwebsite.com/search/thingsearchedfor. 搜索页面包含一堆搜索结果。你想存储这条路线，以防他们想回到它！现在他们单击搜索结果并导航到view/:resultId您不想存储的 ，因为他们可能只会出现一次。有了上面的实现，我会简单地改变shouldDetach方法！下面是它的样子：
首先让我们创建一个我们想要存储的路径数组。
private acceptedRoutes: string[] = ["search/:term"];
现在，shouldDetach我们可以检查route.routeConfig.path我们的数组。
shouldDetach(route: ActivatedRouteSnapshot): boolean {
// check to see if the route's path is in our acceptedRoutes array
if (this.acceptedRoutes.indexOf(route.routeConfig.path) > -1) {
console.log("detaching", route);
return true;
} else {
return false; // will be "view/:resultId" when user navigates to result
}
}
因为 Angular只会存储一个路由实例，所以这个存储是轻量级的，我们只会存储位于的组件，search/:term而不是所有其他的！
附加链接
尽管那里还没有太多文档，但这里有几个链接可以指向存在的内容：
角度文档：https ://angular.io/docs/ts/latest/api/router/index/RouteReuseStrategy-class.html
nativescript-angular 的RouteReuseStrategy默认实现：https ://github.com/NativeScript/nativescript-angular/blob/cb4fd3a/nativescript-angular/router/ns-route-reuse-strategy.ts
于 2017-01-06T22:51:07.477 回答
54
不要被接受的答案吓倒，这很简单。这是您需要的快速答案。我建议至少阅读接受的答案，因为它非常详细。
该解决方案不会像接受的答案那样进行任何参数比较，但它可以很好地存储一组路由。
app.module.ts 进口：
import { RouteReuseStrategy } from '@angular/router';
import { CustomReuseStrategy, Routing } from './shared/routing';
@NgModule({
//...
providers: [
{ provide: RouteReuseStrategy, useClass: CustomReuseStrategy },
]})
共享/路由.ts：
export class CustomReuseStrategy implements RouteReuseStrategy {
routesToCache: string[] = ["dashboard"];
storedRouteHandles = new Map<string, DetachedRouteHandle>();
// Decides if the route should be stored
shouldDetach(route: ActivatedRouteSnapshot): boolean {
return this.routesToCache.indexOf(route.routeConfig.path) > -1;
}
//Store the information for the route we're destructing
store(route: ActivatedRouteSnapshot, handle: DetachedRouteHandle): void {
this.storedRouteHandles.set(route.routeConfig.path, handle);
}
//Return true if we have a stored route object for the next route
shouldAttach(route: ActivatedRouteSnapshot): boolean {
return this.storedRouteHandles.has(route.routeConfig.path);
}
//If we returned true in shouldAttach(), now return the actual route data for restoration
retrieve(route: ActivatedRouteSnapshot): DetachedRouteHandle {
return this.storedRouteHandles.get(route.routeConfig.path);
}
//Reuse the route if we're going to and from the same route
shouldReuseRoute(future: ActivatedRouteSnapshot, curr: ActivatedRouteSnapshot): boolean {
return future.routeConfig === curr.routeConfig;
}
}
于 2017-06-30T20:46:49.197 回答
33
除了接受的答案（Corbfon）和 Chris Fremgen 更简短、更直接的解释之外，我想添加一种更灵活的方式来处理应该使用重用策略的路由。
两个答案都将我们要缓存的路由存储在一个数组中，然后检查当前路由路径是否在数组中。此检查在shouldDetach方法中完成。
我发现这种方法不灵活，因为如果我们想更改路线的名称，我们需要记住还要更改我们CustomReuseStrategy类中的路线名称。我们可能忘记更改它，或者我们团队中的其他开发人员可能决定更改路由名称，甚至不知道RouteReuseStrategy.
RouterModule我们可以直接在using dataobject中标记它们，而不是将我们想要缓存的路由存储在数组中。这样即使我们更改了路由名称，重用策略仍然会被应用。
{
path: 'route-name-i-can-change',
component: TestComponent,
data: {
reuseRoute: true
}
}
然后在shouldDetach方法中我们利用它。
shouldDetach(route: ActivatedRouteSnapshot): boolean {
return route.data.reuseRoute === true;
}
于 2019-07-14T11:31:47.257 回答
22
另一种更有效、更完整和可重用的实现。这个支持延迟加载模块作为@Uğur Dinç 并集成@Davor 路由数据标志。最好的改进是基于页面绝对路径自动生成（几乎）唯一标识符。这样您就不必在每个页面上自己定义它。
标记您要缓存设置的任何页面reuseRoute: true。它将在shouldDetach方法中使用。
{
path: '',
component: MyPageComponent,
data: { reuseRoute: true },
}
这是最简单的策略实现，不比较查询参数。
import { ActivatedRouteSnapshot, RouteReuseStrategy, DetachedRouteHandle, UrlSegment } from '@angular/router'
export class CustomReuseStrategy implements RouteReuseStrategy {
storedHandles: { [key: string]: DetachedRouteHandle } = {};
shouldDetach(route: ActivatedRouteSnapshot): boolean {
return route.data.reuseRoute || false;
}
store(route: ActivatedRouteSnapshot, handle: DetachedRouteHandle): void {
const id = this.createIdentifier(route);
if (route.data.reuseRoute) {
this.storedHandles[id] = handle;
}
}
shouldAttach(route: ActivatedRouteSnapshot): boolean {
const id = this.createIdentifier(route);
const handle = this.storedHandles[id];
const canAttach = !!route.routeConfig && !!handle;
return canAttach;
}
retrieve(route: ActivatedRouteSnapshot): DetachedRouteHandle {
const id = this.createIdentifier(route);
if (!route.routeConfig || !this.storedHandles[id]) return null;
return this.storedHandles[id];
}
shouldReuseRoute(future: ActivatedRouteSnapshot, curr: ActivatedRouteSnapshot): boolean {
return future.routeConfig === curr.routeConfig;
}
private createIdentifier(route: ActivatedRouteSnapshot) {
// Build the complete path from the root to the input route
const segments: UrlSegment[][] = route.pathFromRoot.map(r => r.url);
const subpaths = ([] as UrlSegment[]).concat(...segments).map(segment => segment.path);
// Result: ${route_depth}-${path}
return segments.length + '-' + subpaths.join('/');
}
}
这一个也比较查询参数。compareObjects与@Corbfon 版本相比有一点改进：循环遍历基础对象和比较对象的属性。请记住，您可以使用外部且更可靠的实现，例如 lodashisEqual方法。
import { ActivatedRouteSnapshot, RouteReuseStrategy, DetachedRouteHandle, UrlSegment } from '@angular/router'
interface RouteStorageObject {
snapshot: ActivatedRouteSnapshot;
handle: DetachedRouteHandle;
}
export class CustomReuseStrategy implements RouteReuseStrategy {
storedRoutes: { [key: string]: RouteStorageObject } = {};
shouldDetach(route: ActivatedRouteSnapshot): boolean {
return route.data.reuseRoute || false;
}
store(route: ActivatedRouteSnapshot, handle: DetachedRouteHandle): void {
const id = this.createIdentifier(route);
if (route.data.reuseRoute && id.length > 0) {
this.storedRoutes[id] = { handle, snapshot: route };
}
}
shouldAttach(route: ActivatedRouteSnapshot): boolean {
const id = this.createIdentifier(route);
const storedObject = this.storedRoutes[id];
const canAttach = !!route.routeConfig && !!storedObject;
if (!canAttach) return false;
const paramsMatch = this.compareObjects(route.params, storedObject.snapshot.params);
const queryParamsMatch = this.compareObjects(route.queryParams, storedObject.snapshot.queryParams);
console.log('deciding to attach...', route, 'does it match?');
console.log('param comparison:', paramsMatch);
console.log('query param comparison', queryParamsMatch);
console.log(storedObject.snapshot, 'return: ', paramsMatch && queryParamsMatch);
return paramsMatch && queryParamsMatch;
}
retrieve(route: ActivatedRouteSnapshot): DetachedRouteHandle {
const id = this.createIdentifier(route);
if (!route.routeConfig || !this.storedRoutes[id]) return null;
return this.storedRoutes[id].handle;
}
shouldReuseRoute(future: ActivatedRouteSnapshot, curr: ActivatedRouteSnapshot): boolean {
return future.routeConfig === curr.routeConfig;
}
private createIdentifier(route: ActivatedRouteSnapshot) {
// Build the complete path from the root to the input route
const segments: UrlSegment[][] = route.pathFromRoot.map(r => r.url);
const subpaths = ([] as UrlSegment[]).concat(...segments).map(segment => segment.path);
// Result: ${route_depth}-${path}
return segments.length + '-' + subpaths.join('/');
}
private compareObjects(base: any, compare: any): boolean {
// loop through all properties
for (const baseProperty in { ...base, ...compare }) {
// determine if comparrison object has that property, if not: return false
if (compare.hasOwnProperty(baseProperty)) {
switch (typeof base[baseProperty]) {
// if one is object and other is not: return false
// if they are both objects, recursively call this comparison function
case 'object':
if (typeof compare[baseProperty] !== 'object' || !this.compareObjects(base[baseProperty], compare[baseProperty])) {
return false;
}
break;
// if one is function and other is not: return false
// if both are functions, compare function.toString() results
case 'function':
if (typeof compare[baseProperty] !== 'function' || base[baseProperty].toString() !== compare[baseProperty].toString()) {
return false;
}
break;
// otherwise, see if they are equal using coercive comparison
default:
// tslint:disable-next-line triple-equals
if (base[baseProperty] != compare[baseProperty]) {
return false;
}
}
} else {
return false;
}
}
// returns true only after false HAS NOT BEEN returned through all loops
return true;
}
}
如果您有生成唯一键的最佳方法评论我的答案，我将更新代码。
感谢所有分享解决方案的人。
于 2019-08-09T07:55:51.297 回答
17
要将 Chris Fremgen 的策略与延迟加载的模块一起使用，请将 CustomReuseStrategy 类修改为以下内容：
import {ActivatedRouteSnapshot, DetachedRouteHandle, RouteReuseStrategy} from '@angular/router';
export class CustomReuseStrategy implements RouteReuseStrategy {
routesToCache: string[] = ["company"];
storedRouteHandles = new Map<string, DetachedRouteHandle>();
// Decides if the route should be stored
shouldDetach(route: ActivatedRouteSnapshot): boolean {
return this.routesToCache.indexOf(route.data["key"]) > -1;
}
//Store the information for the route we're destructing
store(route: ActivatedRouteSnapshot, handle: DetachedRouteHandle): void {
this.storedRouteHandles.set(route.data["key"], handle);
}
//Return true if we have a stored route object for the next route
shouldAttach(route: ActivatedRouteSnapshot): boolean {
return this.storedRouteHandles.has(route.data["key"]);
}
//If we returned true in shouldAttach(), now return the actual route data for restoration
retrieve(route: ActivatedRouteSnapshot): DetachedRouteHandle {
return this.storedRouteHandles.get(route.data["key"]);
}
//Reuse the route if we're going to and from the same route
shouldReuseRoute(future: ActivatedRouteSnapshot, curr: ActivatedRouteSnapshot): boolean {
return future.routeConfig === curr.routeConfig;
}
}
最后，在您的功能模块的路由文件中，定义您的键：
{ path: '', component: CompanyComponent, children: [
{path: '', component: CompanyListComponent, data: {key: "company"}},
{path: ':companyID', component: CompanyDetailComponent},
]}
更多信息在这里。
于 2017-12-18T23:30:06.620 回答
4
在我们的案例中，所有提到的解决方案在某种程度上都是不够的。我们有较小的商业应用程序：
- 介绍页面
- 登录页面
- 应用程序（登录后）
我们的要求：
- 延迟加载的模块
- 多级路线
- 将所有路由器/组件状态存储在应用程序部分的内存中
- 在特定路线上使用默认角度重用策略的选项
- 注销时销毁存储在内存中的所有组件
我们路线的简化示例：
const routes: Routes = [{
path: '',
children: [
{
path: '',
canActivate: [CanActivate],
loadChildren: () => import('./modules/dashboard/dashboard.module').then(module => module.DashboardModule)
},
{
path: 'companies',
canActivate: [CanActivate],
loadChildren: () => import('./modules/company/company.module').then(module => module.CompanyModule)
}
]
},
{
path: 'login',
loadChildren: () => import('./modules/login/login.module').then(module => module.LoginModule),
data: {
defaultReuseStrategy: true, // Ignore our custom route strategy
resetReuseStrategy: true // Logout redirect user to login and all data are destroyed
}
}];
重用策略：
export class AppReuseStrategy implements RouteReuseStrategy {
private handles: Map<string, DetachedRouteHandle> = new Map();
// Asks if a snapshot from the current routing can be used for the future routing.
public shouldReuseRoute(future: ActivatedRouteSnapshot, curr: ActivatedRouteSnapshot): boolean {
return future.routeConfig === curr.routeConfig;
}
// Asks if a snapshot for the current route already has been stored.
// Return true, if handles map contains the right snapshot and the router should re-attach this snapshot to the routing.
public shouldAttach(route: ActivatedRouteSnapshot): boolean {
if (this.shouldResetReuseStrategy(route)) {
this.deactivateAllHandles();
return false;
}
if (this.shouldIgnoreReuseStrategy(route)) {
return false;
}
return this.handles.has(this.getKey(route));
}
// Load the snapshot from storage. It's only called, if the shouldAttach-method returned true.
public retrieve(route: ActivatedRouteSnapshot): DetachedRouteHandle | null {
return this.handles.get(this.getKey(route)) || null;
}
// Asks if the snapshot should be detached from the router.
// That means that the router will no longer handle this snapshot after it has been stored by calling the store-method.
public shouldDetach(route: ActivatedRouteSnapshot): boolean {
return !this.shouldIgnoreReuseStrategy(route);
}
// After the router has asked by using the shouldDetach-method and it returned true, the store-method is called (not immediately but some time later).
public store(route: ActivatedRouteSnapshot, handle: DetachedRouteHandle | null): void {
if (!handle) {
return;
}
this.handles.set(this.getKey(route), handle);
}
private shouldResetReuseStrategy(route: ActivatedRouteSnapshot): boolean {
let snapshot: ActivatedRouteSnapshot = route;
while (snapshot.children && snapshot.children.length) {
snapshot = snapshot.children[0];
}
return snapshot.data && snapshot.data.resetReuseStrategy;
}
private shouldIgnoreReuseStrategy(route: ActivatedRouteSnapshot): boolean {
return route.data && route.data.defaultReuseStrategy;
}
private deactivateAllHandles(): void {
this.handles.forEach((handle: DetachedRouteHandle) => this.destroyComponent(handle));
this.handles.clear();
}
private destroyComponent(handle: DetachedRouteHandle): void {
const componentRef: ComponentRef<any> = handle['componentRef'];
if (componentRef) {
componentRef.destroy();
}
}
private getKey(route: ActivatedRouteSnapshot): string {
return route.pathFromRoot
.map((snapshot: ActivatedRouteSnapshot) => snapshot.routeConfig ? snapshot.routeConfig.path : '')
.filter((path: string) => path.length > 0)
.join('');
}
}
于 2019-11-06T20:05:27.363 回答
3
以下是工作！参考：https ://www.cnblogs.com/lovesangel/p/7853364.html
import { ActivatedRouteSnapshot, DetachedRouteHandle, RouteReuseStrategy } from '@angular/router';
export class CustomReuseStrategy implements RouteReuseStrategy {
public static handlers: { [key: string]: DetachedRouteHandle } = {}
private static waitDelete: string
public static deleteRouteSnapshot(name: string): void {
if (CustomReuseStrategy.handlers[name]) {
delete CustomReuseStrategy.handlers[name];
} else {
CustomReuseStrategy.waitDelete = name;
}
}
public shouldDetach(route: ActivatedRouteSnapshot): boolean {
return true;
}
public store(route: ActivatedRouteSnapshot, handle: DetachedRouteHandle): void {
if (CustomReuseStrategy.waitDelete && CustomReuseStrategy.waitDelete == this.getRouteUrl(route)) {
// 如果待删除是当前路由则不存储快照
CustomReuseStrategy.waitDelete = null
return;
}
CustomReuseStrategy.handlers[this.getRouteUrl(route)] = handle
}
public shouldAttach(route: ActivatedRouteSnapshot): boolean {
return !!CustomReuseStrategy.handlers[this.getRouteUrl(route)]
}
/** 从缓存中获取快照，若无则返回nul */
public retrieve(route: ActivatedRouteSnapshot): DetachedRouteHandle {
if (!route.routeConfig) {
return null
}
return CustomReuseStrategy.handlers[this.getRouteUrl(route)]
}
public shouldReuseRoute(future: ActivatedRouteSnapshot, curr: ActivatedRouteSnapshot): boolean {
return future.routeConfig === curr.routeConfig &&
JSON.stringify(future.params) === JSON.stringify(curr.params);
}
private getRouteUrl(route: ActivatedRouteSnapshot) {
return route['_routerState'].url.replace(/\//g, '_')
}
}于 2018-03-09T15:37:57.327 回答
1
我在实施自定义路由重用策略时遇到了这些问题：
- 对路由附加/分离执行操作：管理订阅、清理等；
- 只保留最后一个参数化路由的状态：内存优化；
- 重用组件，而不是状态：使用状态管理工具管理状态。
- “无法重新附加从不同路由创建的 ActivatedRouteSnapshot”错误；
所以我写了一个库来解决这些问题。该库为附加/分离钩子提供服务和装饰器，并使用路由的组件来存储分离的路由，而不是路由的路径。
例子：
/* Usage with decorators */
@onAttach()
public onAttach(): void {
// your code...
}
@onDetach()
public onDetach(): void {
// your code...
}
/* Usage with a service */
public ngOnInit(): void {
this.cacheRouteReuse
.onAttach(HomeComponent) // or any route's component
.subscribe(component => {
// your code...
});
this.cacheRouteReuse
.onDetach(HomeComponent) // or any route's component
.subscribe(component => {
// your code...
});
}
于 2020-06-02T20:01:26.710 回答
1
角度 13（28/02/2022 版本）
在阅读了大量指南和建议后。我可以解释一下：
首先，您必须了解什么是future 和curr。
例如：当您从localhost/ato导航到localhost/b现在您在 b 中。
案例1：你想从/a -> /b
- 应该重用路由：
false因为future !== current. - shouldDetach：
true因为我们将detach在未来保存（）任何东西store并等待重用（attach）。 - shouldRetrieve：
true || fase检查handler是否是我们attach保存的将来要重用的组件。如果没有，我们什么也不做。（在这种情况下是没有）
案例2：你想从/b?id=1 -> /b?id=2
- 应该重用路由：
true因为future === current； - 应该分离：跳过
- 应该检索：跳过
案例3：你想从/b -> /a
- 应该重用路由：
false因为future !== current. - shouldDetach：
true因为我们将detach在未来保存（）任何东西store并等待重用（attach）。 - shouldRetrieve：
true || fase检查handler是否是我们attach保存的将来要重用的组件。如果没有，我们什么也不做。（在这种情况下是肯定的）
行。来自https://stackoverflow.com/a/45788698/5748537的更简单的视觉效果
navigate to a
shouldReuseRoute->return true->do nothing
a->b
shouldReuseRoute()->return false->shouldDetach()->return true->store a
then b->a
shouldReuseRoute()->return false->shouldDetach()->return true->store b->retrieve() return a ->attach() a.
然后从https://stackoverflow.com/a/69004775/5748537获得更多视觉效果
最终来自 Angular 团队的正确代码：https ://github.com/angular/angular/issues/44383
export class CustomRouteReuseStrategy implements RouteReuseStrategy {
private handlers: Map<Route, DetachedRouteHandle> = new Map();
constructor() {}
public shouldDetach(_route: ActivatedRouteSnapshot): boolean {
return true;
}
public store(
route: ActivatedRouteSnapshot,
handle: DetachedRouteHandle
): void {
if (!route.routeConfig) return;
this.handlers.set(route.routeConfig, handle);
}
public shouldAttach(route: ActivatedRouteSnapshot): boolean {
return !!route.routeConfig && !!this.handlers.get(route.routeConfig);
}
public retrieve(route: ActivatedRouteSnapshot): DetachedRouteHandle|null {
if (!route.routeConfig || !this.handlers.has(route.routeConfig)) return null;
return this.handlers.get(route.routeConfig)!;
}
public shouldReuseRoute(
future: ActivatedRouteSnapshot,
curr: ActivatedRouteSnapshot
): boolean {
return future.routeConfig === curr.routeConfig;
}
}
于 2022-02-28T09:37:55.643 回答
0
以上所有答案都很棒，但是如果您有延迟加载路由器并且嵌套过多，则它们都无法正常工作。
为了克服这个问题，shouldReuseRoute需要更改比较路线的路径：
Path A: abc/xyx/3
Path B: abc/rty/8
<abc>
<router-outlet></router-outlet>
</abc>
/* If we move from pathA to pathB or vice versa,
* then `routeConfig` will be same since we are routing within the same abc,
* but to store the handle properly, you should store fullPath as key.
*/
shouldReuseRoute(
future: ActivatedRouteSnapshot,
curr: ActivatedRouteSnapshot
): boolean {
return future.routeConfig === curr.routeConfig;
}
private getPathFromRoot(route: ActivatedRouteSnapshot) {
return (route["_urlSegment"]["segments"] as UrlSegment[])
.map((seg) => seg.path)
.join("/");
}
于 2021-02-04T12:17:17.880 回答