Understanding RxSwift Observable Chain
0
This is my a simplified version of my code:
var myObservable: Observable<MyEnum>
var modelObservable: Observable<Model?>
myObservable = myButton.rx.tap.asSignal()
.asObservable()
.flatMapLatest {
getModel()
}.map { model in
print("this is called")
return model.prop == true ? MyEnum.first : MyEnum.second
}
func getModel() -> Observable<Model?> {
if let model = self.model.value {
return Observable.just(model)
}
createModel()
return modelObservable
}
myObservable.subscribe(onNext: { (enum) in
switch enum {
case .first:
self.presentFirst()
case .second:
self.presentSecond()
}
}).disposed(by: bag)
I was expecting this code to mean that whenever myButton is tapped, this code would run and print "this is called", however, "this is called" is printed also when myOtherObservable is triggered, even when myButton is not tapped. Why does this happen? This makes me think I don't understand Rx. Also, how would I make it behave so that it only runs when the myButton is tapped?
swift observable reactive-programming rx-swift
asked Jan 3 at 18:33
natecraft1natecraft1
1,10742646
|
show 14 more comments
0
This is my a simplified version of my code:
var myObservable: Observable<MyEnum>
var modelObservable: Observable<Model?>
myObservable = myButton.rx.tap.asSignal()
.asObservable()
.flatMapLatest {
getModel()
}.map { model in
print("this is called")
return model.prop == true ? MyEnum.first : MyEnum.second
}
func getModel() -> Observable<Model?> {
if let model = self.model.value {
return Observable.just(model)
}
createModel()
return modelObservable
}
myObservable.subscribe(onNext: { (enum) in
switch enum {
case .first:
self.presentFirst()
case .second:
self.presentSecond()
}
}).disposed(by: bag)
I was expecting this code to mean that whenever myButton is tapped, this code would run and print "this is called", however, "this is called" is printed also when myOtherObservable is triggered, even when myButton is not tapped. Why does this happen? This makes me think I don't understand Rx. Also, how would I make it behave so that it only runs when the myButton is tapped?
swift observable reactive-programming rx-swift
asked Jan 3 at 18:33
natecraft1natecraft1
1,10742646
What ismyOtherObservable, and how is it related tomyButton(i.e. why are you trying toflatMapLatestit in the first place?)
– Alexander
Jan 3 at 20:30
Give this a read first, and let me know if you still have questions medium.com/@navdeepsingh_2336/…
– Alexander
Jan 3 at 20:34
Hey @Alexander okay I updated it to be more in line with what I'm doing. When the button is tapped, I ultimately want to navigate somewhere, but not before getting the current model or fetching a new one.
– natecraft1
Jan 3 at 21:02
1
I have no experience with Swift, but are you subscribing tomyObservableanywhere? Somewhere you will need to subscribe to it to then perform the navigation.
– GregL
Jan 3 at 21:21
This code doesn't print anything because there aren't anysubscribes in it. Post a minimal runnable example. And tell us how the actual output differed from what you expected.
– Daniel T.
Jan 4 at 1:46
|
show 14 more comments
0
0
0
This is my a simplified version of my code:
var myObservable: Observable<MyEnum>
var modelObservable: Observable<Model?>
myObservable = myButton.rx.tap.asSignal()
.asObservable()
.flatMapLatest {
getModel()
}.map { model in
print("this is called")
return model.prop == true ? MyEnum.first : MyEnum.second
}
func getModel() -> Observable<Model?> {
if let model = self.model.value {
return Observable.just(model)
}
createModel()
return modelObservable
}
myObservable.subscribe(onNext: { (enum) in
switch enum {
case .first:
self.presentFirst()
case .second:
self.presentSecond()
}
}).disposed(by: bag)
I was expecting this code to mean that whenever myButton is tapped, this code would run and print "this is called", however, "this is called" is printed also when myOtherObservable is triggered, even when myButton is not tapped. Why does this happen? This makes me think I don't understand Rx. Also, how would I make it behave so that it only runs when the myButton is tapped?
swift observable reactive-programming rx-swift
asked Jan 3 at 18:33
natecraft1natecraft1
1,10742646
This is my a simplified version of my code:
var myObservable: Observable<MyEnum>
var modelObservable: Observable<Model?>
myObservable = myButton.rx.tap.asSignal()
.asObservable()
.flatMapLatest {
getModel()
}.map { model in
print("this is called")
return model.prop == true ? MyEnum.first : MyEnum.second
}
func getModel() -> Observable<Model?> {
if let model = self.model.value {
return Observable.just(model)
}
createModel()
return modelObservable
}
myObservable.subscribe(onNext: { (enum) in
switch enum {
case .first:
self.presentFirst()
case .second:
self.presentSecond()
}
}).disposed(by: bag)
I was expecting this code to mean that whenever myButton is tapped, this code would run and print "this is called", however, "this is called" is printed also when myOtherObservable is triggered, even when myButton is not tapped. Why does this happen? This makes me think I don't understand Rx. Also, how would I make it behave so that it only runs when the myButton is tapped?
swift observable reactive-programming rx-swift
swift observable reactive-programming rx-swift
asked Jan 3 at 18:33
natecraft1natecraft1
1,10742646
asked Jan 3 at 18:33
natecraft1natecraft1
1,10742646
edited Jan 4 at 2:32
natecraft1
asked Jan 3 at 18:33
natecraft1natecraft1
1,10742646
asked Jan 3 at 18:33
natecraft1natecraft1
1,10742646
asked Jan 3 at 18:33
natecraft1natecraft1
1,10742646
1,10742646
What ismyOtherObservable, and how is it related tomyButton(i.e. why are you trying toflatMapLatestit in the first place?)
– Alexander
Jan 3 at 20:30
Give this a read first, and let me know if you still have questions medium.com/@navdeepsingh_2336/…
– Alexander
Jan 3 at 20:34
Hey @Alexander okay I updated it to be more in line with what I'm doing. When the button is tapped, I ultimately want to navigate somewhere, but not before getting the current model or fetching a new one.
– natecraft1
Jan 3 at 21:02
1
I have no experience with Swift, but are you subscribing tomyObservableanywhere? Somewhere you will need to subscribe to it to then perform the navigation.
– GregL
Jan 3 at 21:21
This code doesn't print anything because there aren't anysubscribes in it. Post a minimal runnable example. And tell us how the actual output differed from what you expected.
– Daniel T.
Jan 4 at 1:46
|
show 14 more comments
What ismyOtherObservable, and how is it related tomyButton(i.e. why are you trying toflatMapLatestit in the first place?)
– Alexander
Jan 3 at 20:30
Give this a read first, and let me know if you still have questions medium.com/@navdeepsingh_2336/…
– Alexander
Jan 3 at 20:34
Hey @Alexander okay I updated it to be more in line with what I'm doing. When the button is tapped, I ultimately want to navigate somewhere, but not before getting the current model or fetching a new one.
– natecraft1
Jan 3 at 21:02
1
I have no experience with Swift, but are you subscribing tomyObservableanywhere? Somewhere you will need to subscribe to it to then perform the navigation.
– GregL
Jan 3 at 21:21
This code doesn't print anything because there aren't anysubscribes in it. Post a minimal runnable example. And tell us how the actual output differed from what you expected.
– Daniel T.
Jan 4 at 1:46
What is
myOtherObservable, and how is it related to myButton (i.e. why are you trying to flatMapLatest it in the first place?)– Alexander
Jan 3 at 20:30
What is
myOtherObservable, and how is it related to myButton (i.e. why are you trying to flatMapLatest it in the first place?)– Alexander
Jan 3 at 20:30
Give this a read first, and let me know if you still have questions medium.com/@navdeepsingh_2336/…
– Alexander
Jan 3 at 20:34
Give this a read first, and let me know if you still have questions medium.com/@navdeepsingh_2336/…
– Alexander
Jan 3 at 20:34
Hey @Alexander okay I updated it to be more in line with what I'm doing. When the button is tapped, I ultimately want to navigate somewhere, but not before getting the current model or fetching a new one.
– natecraft1
Jan 3 at 21:02
Hey @Alexander okay I updated it to be more in line with what I'm doing. When the button is tapped, I ultimately want to navigate somewhere, but not before getting the current model or fetching a new one.
– natecraft1
Jan 3 at 21:02
1
1
I have no experience with Swift, but are you subscribing to
myObservable anywhere? Somewhere you will need to subscribe to it to then perform the navigation.– GregL
Jan 3 at 21:21
I have no experience with Swift, but are you subscribing to
myObservable anywhere? Somewhere you will need to subscribe to it to then perform the navigation.– GregL
Jan 3 at 21:21
This code doesn't print anything because there aren't any
subscribes in it. Post a minimal runnable example. And tell us how the actual output differed from what you expected.– Daniel T.
Jan 4 at 1:46
This code doesn't print anything because there aren't any
subscribes in it. Post a minimal runnable example. And tell us how the actual output differed from what you expected.– Daniel T.
Jan 4 at 1:46
|
show 14 more comments
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What is
myOtherObservable, and how is it related tomyButton(i.e. why are you trying toflatMapLatestit in the first place?)– Alexander
Jan 3 at 20:30
Give this a read first, and let me know if you still have questions medium.com/@navdeepsingh_2336/…
– Alexander
Jan 3 at 20:34
Hey @Alexander okay I updated it to be more in line with what I'm doing. When the button is tapped, I ultimately want to navigate somewhere, but not before getting the current model or fetching a new one.
– natecraft1
Jan 3 at 21:02
1
I have no experience with Swift, but are you subscribing to
myObservableanywhere? Somewhere you will need to subscribe to it to then perform the navigation.– GregL
Jan 3 at 21:21
This code doesn't print anything because there aren't any
subscribes in it. Post a minimal runnable example. And tell us how the actual output differed from what you expected.– Daniel T.
Jan 4 at 1:46