Angular2 NGRX / Store视图未更新

Question

Sorry for yet another Angular 2 view update question but I haven't been able to find an answer in any other responses. I'm mentioning the use of NGRX/Store here though I doubt its the reason the view isn't updating.Oddly enough it seems to update once (at least) but manages to stay a step behind. The last (most recent) update never takes affect. When the model updates, the previous state updates in the view. It's mind boggling really. Heres the appropriate code.

Relevant Installed packages

    "@angular/common": "2.0.0-rc.5",
    "@angular/compiler": "2.0.0-rc.5",
    "@angular/core": "2.0.0-rc.5",
    "@angular/forms": "^0.3.0",
    "@angular/http": "2.0.0-rc.5",
    "@angular/platform-browser": "2.0.0-rc.5",
    "@angular/platform-browser-dynamic": "2.0.0-rc.5",
    "@angular/router": "^3.0.0-rc.1",
    "@angular/upgrade": "2.0.0-rc.5",
    "@ngrx/core": "^1.0.1",
    "@ngrx/store": "^2.0.1",

My main app module

@NgModule({
    imports: [
        BrowserModule,
        FormsModule,
        RouterModule.forRoot(AppRoutes)
    ],
    declarations: [
        ConsumerApp,
        AppManagement,
        MyApps,
        AppRegistration,
        AppDetails,
    ],
    providers: [
        HTTP_PROVIDERS,
        STORE_PROVIDERS,
        AppManagementService,
    ],
    bootstrap: [
        ConsumerApp
    ]
})
export class AppModule { }

My-Apps Component

@Component({
    selector: 'my-apps',
    template: require('./templates/my-apps.html')
})
export class MyApps implements OnInit, OnDestroy {

    apps = {};
    change = 1;
    userAppsSubscription;

    constructor (
        private appsService: AppManagementService,
        private store: Store<any> ) {}

    ngOnInit () {

        this.userAppsSubscription = this.store
            .select('userApps')
            .subscribe( userApps => {
                this.apps = Object.assign(this.apps, userApps);
                this.change++;
                console.log(this);
            })

        this.appsService.getUserApps();
    }

    ngOnDestroy () {

        this.userAppsSubscription.unsubscribe();
    }
}

My-Apps template

<div id="my-apps">
    <h1>My Apps</h1>
    <h2>{{change}}</h2>
    <p>You currently don't have any registered applications. Click "Register an App" to get started.</p>

    <p [hidden]="!loading">{{apps | json}}</p>

    <div class="apps-container">  
        <div class="col-md-4 col-sm-6" *ngFor="let app of apps.available">
            <button class="block-button">
                <h3>{{app.name}}</h3>
                <p><strong>Description:</strong> {{app.description}}</p>  
            </button>
        </div>
    </div>

</div>

App Management Service

@Injectable()
export class AppManagementService {

    constructor (
        private http: Http, 
        private store: Store<any>) {}

    getUserApps () {

        this.store
            .dispatch({
                type: RETRIEVE_USER_APPS,
                payload: null
            })

        return this.http
            .get(ALL_APPS)
            .toPromise()
            .then(response => {
                this.store
                    .dispatch({
                        type: RECIEVE_USER_APPS,
                        payload: response.json()
                    })
            })
            .catch(response => {
                this.store
                    .dispatch({
                        type: RETRIEVAL_FAILURE_USER_APPS,
                        payload: null
                    })
            });
    }
}

When the "My Apps" page is first hit this is what end up being printed out.

And this is where the view end up.

Odd right? you can see the page was updated with the second state broadcasted from the NGRX/Store but not the final state Which contains the real bread and butter (the list of 6 apps). Why on earth would the view not update properly?

Answer 1

Can you post your reducer?

I would refactor this to not unwrap the stream in the Init method. Use the async pipe to do this for you. This also handles the unsubscribe.

Something like:

HTML

<div id="my-apps">
    <h1>My Apps</h1>
    <h2>{{change}}</h2>
    <p>You currently don't have any registered applications. Click "Register an App" to get started.</p>

    <p [hidden]="!loading">{{apps | json}}</p>

    <div class="apps-container">  
        <div class="col-md-4 col-sm-6" *ngFor="let app of ($userAppsSubscription | async).apps.available">
            <button class="block-button">
                <h3>{{app.name}}</h3>
                <p><strong>Description:</strong> {{app.description}}</p>  
            </button>
        </div>
    </div>
</div>

TS

@Component({
    selector: 'my-apps',
    template: require('./templates/my-apps.html')
})
export class MyApps implements OnInit, OnDestroy {

    apps = {};
    change = 1;
    $userAppsSubscription:Observable<string>;

    constructor (
        private appsService: AppManagementService,
        private store: Store<any> ) {}

    ngOnInit () {

        this.userAppsSubscription = this.store
            .select('userApps');

        this.appsService.getUserApps();
    }

    ngOnDestroy () {

        this.userAppsSubscription.unsubscribe();
    }
}