AngularJS:如何正确更新服务中的数据?
用异步数据填充服务(实际上是工厂)没有问题。但是,更新服务中数据的正确方法是什么 我遇到的问题是,所有异步数据都是通过AngularJS:如何正确更新服务中的数据?,angularjs,angularjs-service,Angularjs,Angularjs Service,用异步数据填充服务(实际上是工厂)没有问题。但是,更新服务中数据的正确方法是什么 我遇到的问题是,所有异步数据都是通过.then()方法访问的,这基本上是一个承诺解决方案。现在,我如何将某些内容放入服务中,并更新相关视图 我正在使用的服务: function ($q) { var _data = null; return { query: function (expire) { var defer = $q.defer();
.then()
方法访问的,这基本上是一个承诺解决方案。现在,我如何将某些内容放入服务中,并更新相关视图
我正在使用的服务:
function ($q) {
var _data = null;
return {
query: function (expire) {
var defer = $q.defer();
if (_data) {
defer.resolve(response.data);
} else {
$http.get('/path').then(function (response) {
defer.resolve(response.data);
});
}
return defer.promise;
}
,
byId: function(id) {
var defer = $q.defer();
this.query().then(function(data){
angular.forEach(data, function(item) {
if (item.id == id) {
return defer.resolve(item);
}
});
return defer.reject('id not found');
});
return defer.promise;
}
,
add: function(item) {
...
}
};
}
add
方法的良好实现是什么?请注意,我使用的是Angular>1.2
我发布了一些示例,以展示如何将服务中的数据获取到控制器中,从而允许在视图中绑定数据
HTML
<!DOCTYPE html> <html>
<head>
<script data-require="angular.js@*" data-semver="1.2.4" src="http://code.angularjs.org/1.2.3/angular.js"></script>
<link rel="stylesheet" href="style.css" />
<script src="script.js"></script> </head>
<body ng-app="myApp">
<div ng-controller="MyCtrl">
{{sharedData.label}}
<br>
<input type="text" ng-model="sharedData.label"/>
</div>
<div ng-controller="MyCtrl2">
<input type="text" ng-model="sharedData.label"/>
<button ng-click="updateValue()">test</button>
</div>
<div ng-controller="MyCtrl3">
<input type="text" ng-model="sharedData.label"/>
<button ng-click="updateValue()">test</button>
</div>
<div ng-controller="MyCtrl4">
<input type="text" ng-model="sharedData.label"/>
</div>
</body>
</html>
关于服务中的add方法,您希望它执行类似于get的操作,只需创建一个延迟方法,返回承诺,然后执行异步业务(http请求)。对于byId函数,您可能希望使用缓存版本(将查询调用返回的数据保存在服务的属性中)。这样,如果没有必要,就不需要每次都执行查询。实际上,我已经在实际场景中缓存后端调用了。:)然后,一切延期。我会试一试的。然而,这是我自己的第一个想法,只是看起来“不对”。
angular.module("myApp", []).service("MyService", function($q) {
var serviceDef = {};
//It's important that you use an object or an array here a string or other
//primitive type can't be updated with angular.copy and changes to those
//primitives can't be watched.
serviceDef.someServiceData = {
label: 'aValue'
};
serviceDef.doSomething = function() {
var deferred = $q.defer();
angular.copy({
label: 'an updated value'
}, serviceDef.someServiceData);
deferred.resolve(serviceDef.someServiceData);
return deferred.promise;
}
return serviceDef;
}).controller("MyCtrl", function($scope, MyService) {
//Using a data object from the service that has it's properties updated async
$scope.sharedData = MyService.someServiceData;
}).controller("MyCtrl2", function($scope, MyService) {
//Same as above just has a function to modify the value as well
$scope.sharedData = MyService.someServiceData;
$scope.updateValue = function() {
MyService.doSomething();
}
}).controller("MyCtrl3", function($scope, MyService) {
//Shows using a watch to see if the service data has changed during a digest
//if so updates the local scope
$scope.$watch(function(){ return MyService.someServiceData }, function(newVal){
$scope.sharedData = newVal;
})
$scope.updateValue = function() {
MyService.doSomething();
}
}).controller("MyCtrl4", function($scope, MyService) {
//This option relies on the promise returned from the service to update the local
//scope, also since the properties of the object are being updated not the object
//itself this still stays "in sync" with the other controllers and service since
//really they are all referring to the same object.
MyService.doSomething().then(function(newVal) {
$scope.sharedData = newVal;
});
});