订阅的角度返回值 [英] Angular return value from subscribe
本文介绍了订阅的角度返回值的处理方法,对大家解决问题具有一定的参考价值,需要的朋友们下面随着小编来一起学习吧!
问题描述
我需要通过订阅服务电话返回值.这是我的代码
I need to return value from subscribe of a service call. here is my code
export class RideDataSource extends DataSource<any> {
rides: Ride[];
constructor(private _rideService: RidesService,
private _paginator: MatPaginator) {
super();
}
connect(): Observable<Ride[]> {
this._rideService.getActiveRides(this._paginator.pageIndex, this._paginator.pageSize).subscribe(
ridePage => {
this.rides = ridePage.content;
this._paginator.length = ridePage.totalElements;
}
);
// i need to return Observable.of(this.rides);
}
disconnect() {
// No-op
}
}
返回Observable.of(this.rides)无效,因为this.rides是未定义的.有什么办法吗?
returning Observable.of(this.rides) won't work as this.rides will be undefined. is there any way to do this?
推荐答案
请勿订阅该服务,请使用地图运算符,然后订阅connect()
:
Do not subscribe in the service, use the map operator instead and subscribe to connect()
:
connect(): Observable<Ride[]> {
return this._rideService.getActiveRides(
this._paginator.pageIndex,
this._paginator.pageSize
).pipe(
map(ridePage => {
this.rides = ridePage.content;
this._paginator.length = ridePage.totalElements;
return this.rides;
})
);
}
...
connect().subscribe(rides => console.log(rides));
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