rx_future
GetXに新しい型であるRxFutureを導入し、Futureの状態をリッスンするためのものとして使用します。
Getx Rx を統合して新しい型 RxFuture を導入する強力なライブラリで、将来の状態(ロード中、エラー)を扱いやすくし、その将来の結果を取得でき、キャンセル機能なども提供します。
{"sdk":"flutter"}^4.6.1^2.8.2{"sdk":"flutter"}^1.0.0以下は英語原文のスナップショットです。最新版は GitHub をご覧ください。
A powerful library that integrate Getx Rx to introduce a new type called RxFuture which make it easy to handle future states (loading, error) and get the result of this future, with some functionality like canceling the future.
dependencies:
rx_future: ^1.0.2
1- import rx_future and get state manager then create your own GetxController.
import 'package:get/state_manager.dart';
import 'package:rx_future/rx_future.dart';
class MyController extends GetxController {}
2- declare your rxFuture, and pass initial value.
class MyController extends GetxController {
RxFuture<Map<String, dynamic>> state = RxFuture({});
}
3- define your functions to trigger the future
class MyController extends GetxController {
RxFuture<Map<String, dynamic>> state = RxFuture({});
Future<void> getData() async {
}
}
4- now trigger the state by passing a future callback to the observe method.
class MyController extends GetxController {
RxFuture<Map<String, dynamic>> state = RxFuture({});
Future<void> getData() async {
// you have access to value here, so you can maybe depend on it to get a new data.
await state.observe((value) async {
// this callback should return Future<T> or
// Future<Map<String , dynamic>> in our case.
return await myApi();
});
}
}
5- now you can use state.error & state.loading by listening to them in your ui code
Obx(() {
// handle loading state.
if(myController.state.loading){
return const CircularProgressIndicator();
}
// handle error state
if(myController.state.hasError){
return Text(myController.state.error.toString());
}
// you have result to show.
return MyWidget(myController.state.result);
})
That was so easy, wasn't it?
Declare more than one RxFuture for multiple state to handle.
let's have a closer look on more functionality
1- hooks there is many hooks that would be triggered in different situations, here is an example:
await state.observe(
(value) async {
return await myApi();
},
// triggered once our future is completed.
onSuccess: (value) {
print("success $value");
},
// triggered once our future throw an error, providing the error.
onError: (e) {},
// triggered when our future canceled by .cancel() method.
onCancel: () {},
);
for example canceling your future is easy now, just call .cancel() method on your RxFuture
void cancel(){
state.cancel();
}
the above code would cancel any running future in this RxFuture, and would trigger onCancel method.
What happen on multiple calls? what would happen to my state
by default when you call state.observe() more than one time before it is completed, it would ignore the new calls, always changing your state due to your first call until it will completed.
you can change this behavior be passing MultipleCallsBehavior param to the observe method
state.observe(
(val) async {
return await myApi();
},
// the default, ignoring new calls until the first call completed.
multipleCallsBehavior: MultipleCallsBehavior.abortNew,
)
to ignore old calls and refresh your state due to your new calls use MultipleCallsBehavior.abortOld
state.observe(
(val) async {
return await myApi();
},
// the default, ignoring old calls and refresh the state due to new call.
multipleCallsBehavior: MultipleCallsBehavior.abortOld,
)
calling .observe more than one when loading would trigger onMultipleCalls hook
await state.observe(
(value) async {
return await myApi();
},
// triggered once our future is completed.
onMultipleCalls: () {},
);
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