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Error: no se puede volver a adjuntar ActivatedRouteSnapshot creado desde una ruta diferente

Question

Estoy tratando de implementar la clase RouteReuseStrategy . Funciona bien cuando navego a las rutas de nivel superior.

Tan pronto como una ruta tiene rutas secundarias y navego a la ruta secundaria, luego navego de vuelta a una ruta de nivel superior, recibo el siguiente error:

Error: No detectado (en promesa): Error: No se puede volver a adjuntar ActivatedRouteSnapshot creado desde una ruta diferente

He creado un plunker para demostrar el error. Veo que el plunker no funciona en IE 11, véalo en la última versión de Chrome

Pasos para reproducir el error:

Paso 1:

Paso 2

Paso 3

Etapa 4

Puedes ver el error en la consola:

He intentado la implementación encontrada en este article

export class CustomReuseStrategy implements RouteReuseStrategy {

    handlers: {[key: string]: DetachedRouteHandle} = {};

    shouldDetach(route: ActivatedRouteSnapshot): boolean {
        console.debug(''CustomReuseStrategy:shouldDetach'', route);
        return true;
    }

    store(route: ActivatedRouteSnapshot, handle: DetachedRouteHandle): void {
        console.debug(''CustomReuseStrategy:store'', route, handle);
        this.handlers[route.routeConfig.path] = handle;
    }

    shouldAttach(route: ActivatedRouteSnapshot): boolean {
        console.debug(''CustomReuseStrategy:shouldAttach'', route);
        return !!route.routeConfig && !!this.handlers[route.routeConfig.path];
    }

    retrieve(route: ActivatedRouteSnapshot): DetachedRouteHandle {
        console.debug(''CustomReuseStrategy:retrieve'', route);
        if (!route.routeConfig) return null;
        return this.handlers[route.routeConfig.path];
    }

    shouldReuseRoute(future: ActivatedRouteSnapshot, curr: ActivatedRouteSnapshot): boolean {
        console.debug(''CustomReuseStrategy:shouldReuseRoute'', future, curr);
        return future.routeConfig === curr.routeConfig;
    }

}

Y la implementación de esta answer stackoverflow.

/**
 * 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 (===)
     * @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;
    }
}

¿Está RouteReuseStrategy lista para paths secundarias? ¿O hay otra manera de hacer que RouteReuseStrategy trabaje con rutas que contienen paths secundarias?

Answer 1

Agregué una solución alternativa para nunca recuperar las rutas separadas cuando estoy en una ruta con loadChildren modificando mi función de recuperación en la RouteReuseStrategy personalizada.

    retrieve(route: ActivatedRouteSnapshot): DetachedRouteHandle {
       if (!route.routeConfig) return null;
       if(route.routeConfig.loadChildren) return null;
       return this.handlers[route.routeConfig.path];
    }

No estoy seguro de que sea una solución perfecta para todos los escenarios, pero en mi caso funciona.

Answer 2

Aquí hay una manera de generar claves únicas para rutas en la clase de estrategia. Tuve un problema similar, pero una vez que comencé a generar claves únicas, el problema desapareció:

private takeFullUrl(route: ActivatedRouteSnapshot) {
  let next = route;
  // Since navigation is usually relative
  // we go down to find out the child to be shown.
  while (next.firstChild) {
    next = next.firstChild;
  }
  const segments = [];
  // Then build a unique key-path by going to the root.
  while (next) {
    segments.push(next.url.join(''/''));
    next = next.parent;
  }
  return compact(segments.reverse()).join(''/'');
}

Más sobre eso https://github.com/angular/angular/issues/13869#issuecomment-344403045

Answer 3

El enrutador angular es innecesariamente complejo y las estrategias personalizadas continúan esta tendencia.

Su estrategia personalizada utiliza route.routerConfig.path como clave para las rutas almacenadas.

Almacena (sobrescribe) dos rutas diferentes para la misma ruta person/:id :

1. /person/%23123456789%23/edit
2. /person/%23123456789%23/view

La primera vez que se guardó la ruta de vista, la segunda vez que se editó, cuando se abre de nuevo la vista, la última ruta almacenada se edita, pero se espera ver.

Estas rutas no son compatibles según la opinión del enrutador, comprueban los nodos de manera recursiva y descubren que routerConfig para ViewPersonComponent no es lo mismo que routerConfig para EditPersonComponent , ¡boom!

Por lo tanto, routerConfig.path no debe usarse como una clave o es un problema / limitación del diseño del enrutador.

Answer 4

Me encontré con un problema similar y al modificarlo, mi método de clave único lo resolvió.

private routeToUrl(route: ActivatedRouteSnapshot): string {
    if (route.url) {
        if (route.url.length) {
            return route.url.join(''/'');
        } else {
            if (typeof route.component === ''function'') {
                return `[${route.component.name}]`;
            } else if (typeof route.component === ''string'') {
                return `[${route.component}]`;
            } else {
                return `[null]`;
            }
        }
    } else {
        return ''(null)'';
    }
}


private getChildRouteKeys(route:ActivatedRouteSnapshot): string {
    let  url = this.routeToUrl(route);
    return route.children.reduce((fin, cr) => fin += this.getChildRouteKeys(cr), url);
}

private getRouteKey(route: ActivatedRouteSnapshot) {
    let url = route.pathFromRoot.map(it => this.routeToUrl(it)).join(''/'') + ''*'';
    url += route.children.map(cr => this.getChildRouteKeys(cr));
    return url;
}

Anteriormente, solo construí el primer hijo, ahora solo recursivamente construyo mi llave de todos los niños. No escribí la función routeToUrl, la obtuve de un artículo que leí sobre estrategias de reutilización personalizadas hace un tiempo y no está modificada.