refactor: move angular source to /packages rather than modules/@angular

packages/router/src/route_reuse_strategy.ts

@@ -0,0 +1,50 @@
+/**
+ * @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 {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 = {
+  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 */
+  abstract store(route: ActivatedRouteSnapshot, handle: DetachedRouteHandle): 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;
+
+  /** Determines if a route should be reused */
+  abstract shouldReuseRoute(future: ActivatedRouteSnapshot, curr: ActivatedRouteSnapshot): boolean;
+}