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组合多个/ redundent ngrx Store select语句

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我正在使用ngrx / angular4开发一个应用程序 . 这里开发的设计模式似乎非常冗长，它与您如何订阅Store减速器有关 .

在组件中，以下情况并不罕见：

HOFDetails$:Observable<any>;
HOFDetails$SUB:ISubscription;
HOFMobile$:Observable<any>;
HOFMobile$SUB:ISubscription;
HOFMobile:any;
HOFHome$:Observable<any>;
HOFHome$SUB:ISubscription;
HOFHome:any;
SPDetails$:Observable<any>;
SPDetails$SUB:ISubscription;
SPMobile$:Observable<any>;
SPMobile$SUB:ISubscription;
SPMobile:any;
SPHome$:Observable<any>;
SPHome$SUB:ISubscription;
SPHome:any;
EmergencyDetails$:Observable<any>;
EmergencyDetails$SUB:ISubscription;
EmergencyDetails:any;
EmergencyMobile$:Observable<any>;
EmergencyMobile$SUB:ISubscription;
EmergencyMobile:any;
EmergencyHome$:Observable<any>;
EmergencyHome$SUB:ISubscription;
EmergencyHome:any;
EmergencyList$:Observable<any>;
EmergencyList$SUB:ISubscription;
EmergencyList:any;
countries$:Observable<any>;
countries$SUB:ISubscription;
countries:any;
valueIds$:Observable<any>;
valueIds$SUB:ISubscription;
valueIds:any;
lang$:Observable<any>;
lang$SUB:ISubscription; 
//the subscriptions
    this.lang$ =  this.store.select(fromroot.getLanguage);
    this.lang$SUB = this.lang$.subscribe((v:string)=>this.lang = v);
    this.HOFDetails$ = this.store.select(from_costumer.getHOF);
    this.HOFDetails$SUB = this.HOFDetails$.subscribe((v)=> {});
    this.HOFMobile$ = this.store.select(from_costumer.getHOFMobile);
    this.HOFMobile$SUB = this.HOFMobile$.subscribe((v)=> {});
    this.HOFHome$ = this.store.select(from_costumer.getHOFHome);
    this.HOFHome$SUB = this.HOFHome$.subscribe((v)=> {});
    this.SPDetails$ = this.store.select(from_costumer.getSP);
    this.SPDetails$SUB = this.SPDetails$.subscribe((v)=> {});
    this.SPMobile$ = this.store.select(from_costumer.getSPMobile);
    this.SPMobile$SUB = this.SPMobile$.subscribe((v)=> {});
    this.SPHome$ = this.store.select(from_costumer.getSPHome);
    this.SPHome$SUB = this.SPHome$.subscribe((v)=> {});
    this.EmergencyDetails$ = this.store.select(from_costumer.getEmergency);
    this.EmergencyDetails$SUB = this.EmergencyDetails$.subscribe((v)=>this.EmergencyDetails = v);
    this.EmergencyList$ = this.store.select(from_costumer.getEmergencyList);
    this.EmergencyList$SUB = this.EmergencyList$.subscribe((v:any)=> {});
    this.EmergencyMobile$ = this.store.select(from_costumer.getEmergencyMobile);
    this.EmergencyMobile$SUB = this.EmergencyMobile$.subscribe((v:any)=> {});
    this.EmergencyHome$ = this.store.select(from_costumer.getEmergencyHome);
    this.EmergencyHome$SUB = this.EmergencyHome$.subscribe((v:any)=> {});
    this.countries$ = this.store.select(from_geo.getCountries);
    this.countries$SUB = this.countries$.subscribe((v:any)=> this.countries = v);
    this.valueIds$ = this.store.select(from_geo.getCountryIds);
    this.valueIds$SUB = this.valueIds$.subscribe((v:any)=>this.valueIds = v);

所有这些代码仅用于 this this ，不包括订阅和取消订阅中的赋值逻辑 .

这在我看来是令人难以置信的重复和冗余 .

有没有办法把所有这些包装成一些可重复使用的包？也许基于组件或基于路由？

angular angular5 ngrx angular6 ngrx-store

2 回答

  • 1

    删除订阅，删除解压缩的变量（例如 countries:any; ） . 你留下的只是 Observables . 将它们放在容器（智能）组件中，并使用 async 管道将这些可观察对象绑定到您的（哑）表示组件 .

    例如：

    lang$ : Observable<whatevertype>;

constructor(){
   this.lang$ =  this.store.select(fromroot.getLanguage);
}

    在模板中：

    <your-presentational-component [lang]="lang$ | async"><your-presentational-component>

    然后 async 管道接管订阅，取消订阅并将实际值分配给实际使用它们的子组件 .

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  • 2

    在容器组件中缩短它：

    // inject ngrx store in constructor
constructor(private store: Store) {}

// lang$ as class property, no extra code needed.
lang$: Observable<any> = this.store.select(fromroot.getLanguage);

    您可能不需要设置本地prop this.lang ，只需将observable传递给任何表示组件并使用异步管道 .

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