Unraveling the Mystery of Reading AnonymousSubject in Angular 2

Question

Unraveling the Mystery of Reading AnonymousSubject in Angular 2

Currently, I am debugging my ng2 application using console logs. When logging an array, it shows an AnonymousSubject with the following attributes:

AnonymousSubject
_isScalar:false
closed:false
destination:AnonymousSubject
hasError:false
isStopped:false
observers:Array[0]
operator:ToArrayOperator
source:AnonymousSubject
thrownError:null
__proto__:Subject

Is it possible to view the content of the array? Why does clicking 'destination' lead to recursive looping of its content?

Code:

GetFeed(id: UUID): Feed[] {    
    var toReturnFeed: any[];

    this.table.find({id: id}).fetch().subscribe(result => toReturnFeed);
    console.log(toReturnFeed);

    return toReturnFeed;
}

I have more questions, but I'll save them for later. Thank you in advance.

angular debugging typescript rethinkdb

Answer 1

Answer №1

The data being logged is not an actual array, but an Observable that is expected to return an array.

Due to the way you set up this Observable, it creates a cyclic reference as the destination is the same as the origin.

To log the array:

this.someObservable.subscribe((someArray: any[]) => {
    console.log(someArray);
});

From the code you provided, it seems you may be overlooking a crucial aspect of asynchronous methods. You cannot return toReturnFeed directly as it will always be undefined. Instead, you should return the Observable<Feed[]>

GetFeed(id: UUID): Observable<Feed[]> { 
    return this.table.find({id: id}).fetch()
}

You can then invoke this method from another part of your code and retrieve the results like this:

serviceInstance.GetFeed(1).subscribe((returnFeed: Feed[]) => {
    console.log(returnFeed);
});

Answer 2

The data being logged is not an actual array, but an Observable that is expected to return an array.

Due to the way you set up this Observable, it creates a cyclic reference as the destination is the same as the origin.

To log the array:

this.someObservable.subscribe((someArray: any[]) => {
    console.log(someArray);
});

From the code you provided, it seems you may be overlooking a crucial aspect of asynchronous methods. You cannot return toReturnFeed directly as it will always be undefined. Instead, you should return the Observable<Feed[]>

GetFeed(id: UUID): Observable<Feed[]> { 
    return this.table.find({id: id}).fetch()
}

You can then invoke this method from another part of your code and retrieve the results like this:

serviceInstance.GetFeed(1).subscribe((returnFeed: Feed[]) => {
    console.log(returnFeed);
});

Unraveling the Mystery of Reading AnonymousSubject in Angular 2

Answer №1

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