Fluter stream doesn't listen or detect change
.everyoneloves__top-leaderboard:empty,.everyoneloves__mid-leaderboard:empty,.everyoneloves__bot-mid-leaderboard:empty{ height:90px;width:728px;box-sizing:border-box;
}
I have problem, i have 3 dart files,
home.dart contain button with onclick:
final cartEmiter = CartEmitter();
cartEmiter.emitCart("add_cart");
cart.dart contain:
class CartEmitter {
StreamController _controller = StreamController.broadcast();
void emitCart(action) {
_controller.add(action);
// print(action);
}
Stream get cartAction => _controller.stream;
}and in main.dart I have this code to change the cart badge.
StreamSubscription _cartCountSubscribtion;
int _cartCount = 0;
@override
void initState() {
_cartCountSubscribtion = CartEmitter().cartAction.listen((action) {
print(action);
setState(() {
_cartCount++;
});
});
super.initState();
}
@override
void dispose() {
_cartCountSubscribtion.cancel();
super.dispose();
}But it doesn't work, no error, no output printed.
Is my code wrong or how to listen change ?
dart
flutter edited Nov 23 '18 at 8:21
Petar
8310
asked Nov 23 '18 at 8:09
RIFALRIFAL
7712
add a comment |
I have problem, i have 3 dart files,
home.dart contain button with onclick:
final cartEmiter = CartEmitter();
cartEmiter.emitCart("add_cart");
cart.dart contain:
class CartEmitter {
StreamController _controller = StreamController.broadcast();
void emitCart(action) {
_controller.add(action);
// print(action);
}
Stream get cartAction => _controller.stream;
}and in main.dart I have this code to change the cart badge.
StreamSubscription _cartCountSubscribtion;
int _cartCount = 0;
@override
void initState() {
_cartCountSubscribtion = CartEmitter().cartAction.listen((action) {
print(action);
setState(() {
_cartCount++;
});
});
super.initState();
}
@override
void dispose() {
_cartCountSubscribtion.cancel();
super.dispose();
}But it doesn't work, no error, no output printed.
Is my code wrong or how to listen change ?
dart
flutter edited Nov 23 '18 at 8:21
Petar
8310
asked Nov 23 '18 at 8:09
RIFALRIFAL
7712
add a comment |
I have problem, i have 3 dart files,
home.dart contain button with onclick:
final cartEmiter = CartEmitter();
cartEmiter.emitCart("add_cart");
cart.dart contain:
class CartEmitter {
StreamController _controller = StreamController.broadcast();
void emitCart(action) {
_controller.add(action);
// print(action);
}
Stream get cartAction => _controller.stream;
}and in main.dart I have this code to change the cart badge.
StreamSubscription _cartCountSubscribtion;
int _cartCount = 0;
@override
void initState() {
_cartCountSubscribtion = CartEmitter().cartAction.listen((action) {
print(action);
setState(() {
_cartCount++;
});
});
super.initState();
}
@override
void dispose() {
_cartCountSubscribtion.cancel();
super.dispose();
}But it doesn't work, no error, no output printed.
Is my code wrong or how to listen change ?
dart
flutter edited Nov 23 '18 at 8:21
Petar
8310
asked Nov 23 '18 at 8:09
RIFALRIFAL
7712
I have problem, i have 3 dart files,
home.dart contain button with onclick:
final cartEmiter = CartEmitter();
cartEmiter.emitCart("add_cart");
cart.dart contain:
class CartEmitter {
StreamController _controller = StreamController.broadcast();
void emitCart(action) {
_controller.add(action);
// print(action);
}
Stream get cartAction => _controller.stream;
}and in main.dart I have this code to change the cart badge.
StreamSubscription _cartCountSubscribtion;
int _cartCount = 0;
@override
void initState() {
_cartCountSubscribtion = CartEmitter().cartAction.listen((action) {
print(action);
setState(() {
_cartCount++;
});
});
super.initState();
}
@override
void dispose() {
_cartCountSubscribtion.cancel();
super.dispose();
}But it doesn't work, no error, no output printed.
Is my code wrong or how to listen change ?
class CartEmitter {
StreamController _controller = StreamController.broadcast();
void emitCart(action) {
_controller.add(action);
// print(action);
}
Stream get cartAction => _controller.stream;
}class CartEmitter {
StreamController _controller = StreamController.broadcast();
void emitCart(action) {
_controller.add(action);
// print(action);
}
Stream get cartAction => _controller.stream;
}StreamSubscription _cartCountSubscribtion;
int _cartCount = 0;
@override
void initState() {
_cartCountSubscribtion = CartEmitter().cartAction.listen((action) {
print(action);
setState(() {
_cartCount++;
});
});
super.initState();
}
@override
void dispose() {
_cartCountSubscribtion.cancel();
super.dispose();
}StreamSubscription _cartCountSubscribtion;
int _cartCount = 0;
@override
void initState() {
_cartCountSubscribtion = CartEmitter().cartAction.listen((action) {
print(action);
setState(() {
_cartCount++;
});
});
super.initState();
}
@override
void dispose() {
_cartCountSubscribtion.cancel();
super.dispose();
}dart
flutter dart
flutter edited Nov 23 '18 at 8:21
Petar
8310
asked Nov 23 '18 at 8:09
RIFALRIFAL
7712
edited Nov 23 '18 at 8:21
Petar
8310
asked Nov 23 '18 at 8:09
RIFALRIFAL
7712
edited Nov 23 '18 at 8:21
Petar
8310
edited Nov 23 '18 at 8:21
Petar
8310
edited Nov 23 '18 at 8:21
Petar
8310
8310
asked Nov 23 '18 at 8:09
RIFALRIFAL
7712
asked Nov 23 '18 at 8:09
RIFALRIFAL
7712
asked Nov 23 '18 at 8:09
RIFALRIFAL
7712
7712
add a comment |
add a comment |
1 Answer
1
active
oldest
votes
You create a new CartEmitter in the initState function, and another one in the onclick code. Those two are not connected in any way, so the event you emit with the emitCart call is emitted on a different CartEmitter than the one you listen to.
You need to share the same CartEmitter instance between the initState and onclick code.
Alternatively, if you know that you will only ever need one CartEmitter, you can make the _controller static, so the same controller (and stream) is shared between all instances of CartEmitter.
In that case, you can make emitCart and cartAction static too, and never create any CartEmitter instance at all.
answered Nov 23 '18 at 8:27
lrnlrn
11.4k1527
so how to use or define same CartEmitter on different file?
– RIFAL
Nov 23 '18 at 8:29
oh done, i define final cartemitter on cart.dart thanks for your help
– RIFAL
Nov 23 '18 at 8:32
add a comment |
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1 Answer
1
active
oldest
votes
1 Answer
1
active
oldest
votes
active
oldest
votes
active
oldest
votes
You create a new CartEmitter in the initState function, and another one in the onclick code. Those two are not connected in any way, so the event you emit with the emitCart call is emitted on a different CartEmitter than the one you listen to.
You need to share the same CartEmitter instance between the initState and onclick code.
Alternatively, if you know that you will only ever need one CartEmitter, you can make the _controller static, so the same controller (and stream) is shared between all instances of CartEmitter.
In that case, you can make emitCart and cartAction static too, and never create any CartEmitter instance at all.
answered Nov 23 '18 at 8:27
lrnlrn
11.4k1527
so how to use or define same CartEmitter on different file?
– RIFAL
Nov 23 '18 at 8:29
oh done, i define final cartemitter on cart.dart thanks for your help
– RIFAL
Nov 23 '18 at 8:32
add a comment |
You create a new CartEmitter in the initState function, and another one in the onclick code. Those two are not connected in any way, so the event you emit with the emitCart call is emitted on a different CartEmitter than the one you listen to.
You need to share the same CartEmitter instance between the initState and onclick code.
Alternatively, if you know that you will only ever need one CartEmitter, you can make the _controller static, so the same controller (and stream) is shared between all instances of CartEmitter.
In that case, you can make emitCart and cartAction static too, and never create any CartEmitter instance at all.
answered Nov 23 '18 at 8:27
lrnlrn
11.4k1527
so how to use or define same CartEmitter on different file?
– RIFAL
Nov 23 '18 at 8:29
oh done, i define final cartemitter on cart.dart thanks for your help
– RIFAL
Nov 23 '18 at 8:32
add a comment |
You create a new CartEmitter in the initState function, and another one in the onclick code. Those two are not connected in any way, so the event you emit with the emitCart call is emitted on a different CartEmitter than the one you listen to.
You need to share the same CartEmitter instance between the initState and onclick code.
Alternatively, if you know that you will only ever need one CartEmitter, you can make the _controller static, so the same controller (and stream) is shared between all instances of CartEmitter.
In that case, you can make emitCart and cartAction static too, and never create any CartEmitter instance at all.
answered Nov 23 '18 at 8:27
lrnlrn
11.4k1527
You create a new CartEmitter in the initState function, and another one in the onclick code. Those two are not connected in any way, so the event you emit with the emitCart call is emitted on a different CartEmitter than the one you listen to.
You need to share the same CartEmitter instance between the initState and onclick code.
Alternatively, if you know that you will only ever need one CartEmitter, you can make the _controller static, so the same controller (and stream) is shared between all instances of CartEmitter.
In that case, you can make emitCart and cartAction static too, and never create any CartEmitter instance at all.
answered Nov 23 '18 at 8:27
lrnlrn
11.4k1527
answered Nov 23 '18 at 8:27
lrnlrn
11.4k1527
answered Nov 23 '18 at 8:27
lrnlrn
11.4k1527
answered Nov 23 '18 at 8:27
lrnlrn
11.4k1527
11.4k1527
so how to use or define same CartEmitter on different file?
– RIFAL
Nov 23 '18 at 8:29
oh done, i define final cartemitter on cart.dart thanks for your help
– RIFAL
Nov 23 '18 at 8:32
add a comment |
so how to use or define same CartEmitter on different file?
– RIFAL
Nov 23 '18 at 8:29
oh done, i define final cartemitter on cart.dart thanks for your help
– RIFAL
Nov 23 '18 at 8:32
so how to use or define same CartEmitter on different file?
– RIFAL
Nov 23 '18 at 8:29
so how to use or define same CartEmitter on different file?
– RIFAL
Nov 23 '18 at 8:29
oh done, i define final cartemitter on cart.dart thanks for your help
– RIFAL
Nov 23 '18 at 8:32
oh done, i define final cartemitter on cart.dart thanks for your help
– RIFAL
Nov 23 '18 at 8:32
add a comment |
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