我最近发布了一篇关于我在SO面临的问题的详细描述。由于我无法发送一个实际的$http请求，所以我使用timeout来模拟异步行为。在@Gloopy的帮助下，从我的模型到视图的数据绑定工作正常
现在，当我使用$http而不是$timeout(在本地测试)时，我可以看到异步请求是成功的，数据在我的服务中被json响应填充。但是，我的观点并没有更新。
在这里更新Plunkr
当前回答
这里有一个Plunk，可以做你想要的:http://plnkr.co/edit/TTlbSv?p=preview
其思想是直接使用承诺及其“then”函数来操作和访问异步返回的响应。
app.factory('myService', function($http) {
var myService = {
async: function() {
// $http returns a promise, which has a then function, which also returns a promise
var promise = $http.get('test.json').then(function (response) {
// The then function here is an opportunity to modify the response
console.log(response);
// The return value gets picked up by the then in the controller.
return response.data;
});
// Return the promise to the controller
return promise;
}
};
return myService;
});
app.controller('MainCtrl', function( myService,$scope) {
// Call the async method and then do stuff with what is returned inside our own then function
myService.async().then(function(d) {
$scope.data = d;
});
});
这里有一个稍微复杂一点的版本，它缓存了请求，所以您只在第一次发出请求(http://plnkr.co/edit/2yH1F4IMZlMS8QsV9rHv?p=preview):
app.factory('myService', function($http) {
var promise;
var myService = {
async: function() {
if ( !promise ) {
// $http returns a promise, which has a then function, which also returns a promise
promise = $http.get('test.json').then(function (response) {
// The then function here is an opportunity to modify the response
console.log(response);
// The return value gets picked up by the then in the controller.
return response.data;
});
}
// Return the promise to the controller
return promise;
}
};
return myService;
});
app.controller('MainCtrl', function( myService,$scope) {
$scope.clearData = function() {
$scope.data = {};
};
$scope.getData = function() {
// Call the async method and then do stuff with what is returned inside our own then function
myService.async().then(function(d) {
$scope.data = d;
});
};
});
其他回答
简单点。这很简单
在您服务期间退货承诺(在您服务期间无需使用) 在你的控制器中使用then
演示。http://plnkr.co/edit/cbdG5p?p=preview
var app = angular.module('plunker', []);
app.factory('myService', function($http) {
return {
async: function() {
return $http.get('test.json'); //1. this returns promise
}
};
});
app.controller('MainCtrl', function( myService,$scope) {
myService.async().then(function(d) { //2. so you can use .then()
$scope.data = d;
});
});
在将UI绑定到数组时，您需要确保通过将长度设置为0并将数据推入数组来直接更新相同的数组。
而不是这个(设置一个不同的数组引用数据，你的UI不会知道):
myService.async = function() {
$http.get('test.json')
.success(function (d) {
data = d;
});
};
试试这个:
myService.async = function() {
$http.get('test.json')
.success(function (d) {
data.length = 0;
for(var i = 0; i < d.length; i++){
data.push(d[i]);
}
});
};
下面是一个演示，显示了设置一个新数组与清空和添加到现有数组之间的区别。我不能让你的plnkr工作，但希望这对你有用!
我读过http://markdalgleish.com/2013/06/using-promises-in-angularjs-views/ [AngularJS允许我们通过直接在作用域上放置承诺来简化我们的控制器逻辑，而不是在成功回调中手动处理已解析的值。]
如此简单和方便:)
var app = angular.module('myApp', []);
app.factory('Data', function($http,$q) {
return {
getData : function(){
var deferred = $q.defer();
var promise = $http.get('./largeLoad').success(function (response) {
deferred.resolve(response);
});
// Return the promise to the controller
return deferred.promise;
}
}
});
app.controller('FetchCtrl',function($scope,Data){
$scope.items = Data.getData();
});
希望这对你有所帮助
至于在服务中缓存响应，这里有另一个版本，似乎比我目前看到的更直接:
App.factory('dataStorage', function($http) {
var dataStorage;//storage for cache
return (function() {
// if dataStorage exists returned cached version
return dataStorage = dataStorage || $http({
url: 'your.json',
method: 'GET',
cache: true
}).then(function (response) {
console.log('if storage don\'t exist : ' + response);
return response;
});
})();
});
该服务将返回缓存的数据或$http.get;
dataStorage.then(function(data) {
$scope.data = data;
},function(e){
console.log('err: ' + e);
});
这里有一个Plunk，可以做你想要的:http://plnkr.co/edit/TTlbSv?p=preview
其思想是直接使用承诺及其“then”函数来操作和访问异步返回的响应。
app.factory('myService', function($http) {
var myService = {
async: function() {
// $http returns a promise, which has a then function, which also returns a promise
var promise = $http.get('test.json').then(function (response) {
// The then function here is an opportunity to modify the response
console.log(response);
// The return value gets picked up by the then in the controller.
return response.data;
});
// Return the promise to the controller
return promise;
}
};
return myService;
});
app.controller('MainCtrl', function( myService,$scope) {
// Call the async method and then do stuff with what is returned inside our own then function
myService.async().then(function(d) {
$scope.data = d;
});
});
这里有一个稍微复杂一点的版本，它缓存了请求，所以您只在第一次发出请求(http://plnkr.co/edit/2yH1F4IMZlMS8QsV9rHv?p=preview):
app.factory('myService', function($http) {
var promise;
var myService = {
async: function() {
if ( !promise ) {
// $http returns a promise, which has a then function, which also returns a promise
promise = $http.get('test.json').then(function (response) {
// The then function here is an opportunity to modify the response
console.log(response);
// The return value gets picked up by the then in the controller.
return response.data;
});
}
// Return the promise to the controller
return promise;
}
};
return myService;
});
app.controller('MainCtrl', function( myService,$scope) {
$scope.clearData = function() {
$scope.data = {};
};
$scope.getData = function() {
// Call the async method and then do stuff with what is returned inside our own then function
myService.async().then(function(d) {
$scope.data = d;
});
};
});
