问题
I am a complete beginner to AngularDart (and Dart); I followed the tutorials but this is something I can't seem to find a answer to.
I have two NgComponents that work perfectly:
<colorImage car-color="ctrl.car.color"></colorImage>
<carImage car="ctrl.car"></carImage>
My controller "ctrl" has a property named "car" and "car" has a property named "color". When "car.color" changes, the colorButton NgComponent updates, but the carImage NgComponent does not.
How can I trigger an update of carImage when "car.color" changes?
Thanks!!
回答1:
You have to set a watch to car.color
inside your CarImage.
How this looks depends on what data structure you use for car.
// constructor
CarImage(Scope scope) {
scope.$watch(() => car.color, (color) => doSomething(color));
}
回答2:
Here is working example without a scope
and a watch
features. I believe this is an angulardartish solution.
Something more about the issue: https://stackoverflow.com/a/21958268/2777805
ang_testi.dart
import 'package:angular/angular.dart';
@NgComponent(
selector: 'colorImage',
template: r'<p>colorImage: <input type="text" ng-model="cmp.carColor"></p>',
publishAs: 'cmp'
)
class colorImage {
@NgTwoWay('car-color')
String carColor;
}
@NgComponent(
selector: 'carImage',
template: r'<p>carImage: <input type="text" ng-model="cmp.car.color"></p>',
publishAs: 'cmp'
)
class carImage {
@NgTwoWay('car')
Map car;
}
@NgController(
selector: '[main-test]',
publishAs: 'ctrl')
class MainTestController {
Map car = {"color":"green", "image":"someImage"};
}
class MyAppModule extends Module {
MyAppModule() {
type(MainTestController);
type(colorImage);
type(carImage);
}
}
void main() {
ngBootstrap(module: new MyAppModule());
}
ang_testi.html
<!DOCTYPE html>
<html ng-app>
<head>
<meta charset="utf-8">
<title>ng-model test</title>
<link rel="stylesheet" href="ang_testi.css">
</head>
<body main-test>
<colorImage car-color="ctrl.car.color"></colorImage>
<carImage car="ctrl.car"></carImage>
<p>controller: <input type="text" ng-model="ctrl.car.color"></p>
<p>color is {{ctrl.car.color}}</p>
<script src="packages/shadow_dom/shadow_dom.min.js"></script>
<script type="application/dart" src="ang_testi.dart"></script>
<script src="packages/browser/dart.js"></script>
</body>
</html>
来源:https://stackoverflow.com/questions/21773823/how-to-trigger-an-update-of-ngcomponent-when-child-property-changes