angular-cn/packages/router/src/route_reuse_strategy.ts

70 lines
2.3 KiB
TypeScript

/**
* @license
* Copyright Google Inc. All Rights Reserved.
*
* Use of this source code is governed by an MIT-style license that can be
* found in the LICENSE file at https://angular.io/license
*/
import {ComponentRef} from '@angular/core';
import {OutletContext} from './router_outlet_context';
import {ActivatedRoute, ActivatedRouteSnapshot} from './router_state';
import {TreeNode} from './utils/tree';
/**
* @whatItDoes Represents the detached route tree.
*
* This is an opaque value the router will give to a custom route reuse strategy
* to store and retrieve later on.
*
* @experimental
*/
export type DetachedRouteHandle = {};
/** @internal */
export type DetachedRouteHandleInternal = {
contexts: Map<string, OutletContext>,
componentRef: ComponentRef<any>,
route: TreeNode<ActivatedRoute>,
};
/**
* @whatItDoes Provides a way to customize when activated routes get reused.
*
* @experimental
*/
export abstract class RouteReuseStrategy {
/** Determines if this route (and its subtree) should be detached to be reused later */
abstract shouldDetach(route: ActivatedRouteSnapshot): boolean;
/**
* Stores the detached route.
*
* Storing a `null` value should erase the previously stored value.
*/
abstract store(route: ActivatedRouteSnapshot, handle: DetachedRouteHandle|null): void;
/** Determines if this route (and its subtree) should be reattached */
abstract shouldAttach(route: ActivatedRouteSnapshot): boolean;
/** Retrieves the previously stored route */
abstract retrieve(route: ActivatedRouteSnapshot): DetachedRouteHandle|null;
/** Determines if a route should be reused */
abstract shouldReuseRoute(future: ActivatedRouteSnapshot, curr: ActivatedRouteSnapshot): boolean;
}
/**
* Does not detach any subtrees. Reuses routes as long as their route config is the same.
*/
export class DefaultRouteReuseStrategy implements RouteReuseStrategy {
shouldDetach(route: ActivatedRouteSnapshot): boolean { return false; }
store(route: ActivatedRouteSnapshot, detachedTree: DetachedRouteHandle): void {}
shouldAttach(route: ActivatedRouteSnapshot): boolean { return false; }
retrieve(route: ActivatedRouteSnapshot): DetachedRouteHandle|null { return null; }
shouldReuseRoute(future: ActivatedRouteSnapshot, curr: ActivatedRouteSnapshot): boolean {
return future.routeConfig === curr.routeConfig;
}
}