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AngularJS:从rest服务获取数据延迟,导致在使用数据时出现html问题

angularjs mongodb javascript

Mohamed Hussain · 技术社区 · 11 年前

我正在开发一个angular应用程序,使用Mongo作为DB和Java。

当我点击获取数据按钮时,我正试图从mongo DB中获取数据。请参阅js bin中的代码 http://jsbin.com/aRuWInU/2/edit ,对于我的html页面,请参阅下面的代码:

<!DOCTYPE html>
<html ng-app="myapp">
<head>
<script src="/angular.js"></script>
<script src="myscript.js"></script>
<meta charset=utf-8 />
<title>Demo</title>

  </head>

<body ng-controller="MyApp">
    <!--It will fetch data from Mongo Using REST service through 
    the angular factory ConsumptionEngineRESTService-->
    <button type="button" ng-click="getAllData()">Get Data</button>
    <h1>My Demo With filter</h1>
    <div ng-repeat="Maindata in myFilteredKey" class="">
        <h2>{{Maindata}}</h2>
        <div ng-repeat="item in data | filter:{'key':Maindata}">
            <p>My key is {{item.key}}</p>
            <p>My val is {{item.value}}</p>
        </div>

    </div>

</body>
</html>

当我从REST服务获取数据时会发生问题, 获取数据的延迟会导致问题,例如$scope.data未填充,但在下面的for循环中用于填充$scope.myFilteredKey数组,因此我的$scope.myFilteredKey阵列为空。请参阅myscript.js的代码

myscript.js
    var app = angular.module('myapp', []);

app.controller('MyApp', ['$scope', function($scope,ConsumptionEngineRESTService) {
        $scope.getAllData=function(){
            console.log("hi");
            /*STUB Data: when it is used , code is working perfectly*/
              /* $scope.data = [
                {key:"home",value:"hk1"},
                {key:"home",value:"hk2"},
                {key:"home",value:"hk3"},
                {key:"home",value:"hk4"},
                {key:"product",value:"pk1"},
                {key:"product",value:"pk2"},
                {key:"product",value:"pk3"},
                {key:"product",value:"pk4"},
                {key:"service",value:"sk1"},
                {key:"service",value:"sk2"},
                {key:"service",value:"sk3"},
                {key:"service",value:"sk4"}
            ]; */
            /* Data From REST Service: Issue happens when i fetch data from REST service,
            *Delay in fetching data cause me the issue, such as $scope.data is not populated but
            *that is used in the below for loop to populate the $scope.myFilteredKey array*/
            /*ConsumptionEngineRESTService is a angular factory. uses REST service to fetch from Mongo*/
            $scope.data =ConsumptionEngineRESTService.getAll();
            $scope.myFilteredKey=[];
            for(i=0;i<$scope.data.length;i++){
                if($scope.myFilteredKey.indexOf($scope.data[i].key)==-1){
                    $scope.myFilteredKey.push($scope.data[i].key);
                    console.log($scope.data[i].key);
                }
            }
        }
}]);

请帮助我解决这个问题,即当for循环执行时,我想填充$scope.data,因为for循环正在使用$scope.data。注意:对于这个问题,我没有包括REST服务角度工厂 ConsumptionEngineRESTService .

app.factory("ConsumptionEngineRESTService ", function($resource, $http) {
  var resource = $resource("/rest/:ID ", { ID : "@_ID " },
    {
      'create':  { method: 'POST' },
      'getAll':   { method: 'GET', isArray: true },
      'get':    { method: 'GET', isArray: false },
      'update':  { method: 'PUT' },
      'destroy': { method: 'DELETE' }
    }
  );
  return resource;
});

请帮我做这件事。谢谢你提前提供的帮助。

1 回复 | 直到 11 年前

mnemosyn 11 年前

我认为 ConsumptionEngineRESTService.getAll(); 内部使用角资源?

如果是这样的话(如果是使用角度 $http 服务),您将不得不在成功回调中处理您的数据。resource和http方法的结果只是承诺,即代理对象,它们最终会包含数据,但不会马上包含。您的代码应该是这样的:

$scope.data = ConsumptionEngineRESTService.getAll(function() {
    $scope.myFilteredKey=[];
    // note that you can work with $scope.data in here, because it's been 
    // assigned before
    for(i = 0; i < $scope.data.length; i++) {
        if($scope.myFilteredKey.indexOf($scope.data[i].key)==-1){
            $scope.myFilteredKey.push($scope.data[i].key);
            console.log($scope.data[i].key);
        }
    }
});

如果你 ConsumptionEngineRESTService 还不支持此回调,我建议您仔细查看的文档 angular-resource “卡片”示例代码第8行采用了完全相同的模式。