RxJs Subject: Acquiring the Sender

Question

RxJs Subject: Acquiring the Sender

I have been working with Subjects and there is a .subscribe() in a specific class. Emitting values to this class from different other classes has resulted in the subscribe function being triggered multiple times, yet I am unsure of where these emits are coming from.

Is there a method to identify the class or reference from which the emit (.next<T>) was initiated?

Expected behavior:

In the service svc:

obs: Subject<Date> = new Subject<Date>();

Class 1:

svc.obs.next(new Date());

Class n:

svc.obs.next(new Date());

Subscriber:

svc.obs.subscribe((date) => {
        console.log("Triggered from: " + svc.obs.getSource().classname); // Desired output: "Triggered from: SomeNamespace.Classname"
});

angular typescript rxjs

Answer 1

Answer №1

You have the option to swap out

obs: Subject<Date> = new Subject<Date>();

with

obs: Subject<any> = new Subject<any>();

After this modification, you can now emit the source on your own

svc.obs.next({ date: new Date(), source: 'whatever source' });

Lastly, when subscribing:

svc.obs.subscribe((data) => {
        console.log("Triggered from: " + data.source + "Date is : "+data.date);
});

Answer 2

You have the option to swap out

obs: Subject<Date> = new Subject<Date>();

with

obs: Subject<any> = new Subject<any>();

After this modification, you can now emit the source on your own

svc.obs.next({ date: new Date(), source: 'whatever source' });

Lastly, when subscribing:

svc.obs.subscribe((data) => {
        console.log("Triggered from: " + data.source + "Date is : "+data.date);
});

Answer 3

Answer №2

A neat solution to tackling this issue is as follows.

Within the service.

// Start by defining an interface like this.
interface ReactiveDate {
    date: Date,
    type: String
}

// Create a Subject using this interface as the generic type.
obs: Subject<ReactiveDate> = new Subject<ReactiveDate>();

Inside your different classes.

// In Class 1.
svc.obs.next({ date: new Date(), type: 'Class 1' });

// In Class 2.
svc.obs.next({ date: new Date(), type: 'Class 2' });

Next, back in your service.

// Implement appropriate logic for "type" within the subscribe callback.
obs.subscribe(({ date, type }) => {
        console.log("Activated from: " + type);
});

By customizing the "type" parameter, you ensure a strong and error-free system since you have predefined values at your disposal. No need for workarounds!

Answer 4

A neat solution to tackling this issue is as follows.

Within the service.

// Start by defining an interface like this.
interface ReactiveDate {
    date: Date,
    type: String
}

// Create a Subject using this interface as the generic type.
obs: Subject<ReactiveDate> = new Subject<ReactiveDate>();

Inside your different classes.

// In Class 1.
svc.obs.next({ date: new Date(), type: 'Class 1' });

// In Class 2.
svc.obs.next({ date: new Date(), type: 'Class 2' });

Next, back in your service.

// Implement appropriate logic for "type" within the subscribe callback.
obs.subscribe(({ date, type }) => {
        console.log("Activated from: " + type);
});

By customizing the "type" parameter, you ensure a strong and error-free system since you have predefined values at your disposal. No need for workarounds!

RxJs Subject: Acquiring the Sender

Answer №1

Answer №2

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