在 IE 上运行时，'Promise' 是未定义的错误

Question

我有一个在 Chrome 上运行良好的控制器代码，但在 IE 10 上运行时返回相同的代码

ReferenceError: 'Promise' is undefined

返回错误的函数是：

new Promise(function(resolve) {
    MetaModel.load($scope, (regionExist ? reqParmRegion[1] : reqParmRegion), (screenExist ? reqParmScreen[1] : reqParmScreen), resolve);
}).then(function(){

    loadRelationshipByStep($scope.preStep);
     if($rootScope.regionId === 'us') {
        $rootScope.currRel = 'itself';
    } 

    if($rootScope.screenId.indexOf('search') !== -1 ){
       EnumerationService.loadEnumerationByTab();
    }  
    // load data for tab click
    if($rootScope.currRel !== 'undefined' && $rootScope.currRel !== 'itself' && $scope.regionId !== 'us'){
        $scope.loadDataByTab($rootScope.currRel);
    } else if($rootScope.resourceHref !== undefined) {
        var params = {};
         resourceFactory.get($rootScope.resourceHref, params, $rootScope.headers).success(function(responseData){
            var data = responseData.data || responseData;
            if (data) {
                $scope.data=data;
                EnumerationService.executeEnumerationFromBackEnd(data, 'create');
                if($rootScope.regionId === 'us'){
                    EnumerationService.executeEnumerationFromBackEnd(data, 'fetch');    
                }
            }
        });            
    }
});

我需要添加任何 $promise 变量吗？

Answer 1

IE原生不支持原生javascript Promise。请参阅MDN 上的浏览​​器兼容性。

Angular 包括$q提供承诺功能的服务。您可以使用该对象创建延迟对象$q.defer()并返回该对象的承诺。

我认为等效的代码是：

// create the deferred object
var deferred = $q.defer();

// pass the resolve method as the callback
MetaModel.load($scope, (regionExist ? reqParmRegion[1] : reqParmRegion), 
    (screenExist ? reqParmScreen[1] : reqParmScreen), deferred.resolve);

// chain actions onto the promise.
deferred.promise.then(function(){

    loadRelationshipByStep($scope.preStep);
     if($rootScope.regionId === 'us') {
        $rootScope.currRel = 'itself';
    } 

    if($rootScope.screenId.indexOf('search') !== -1 ){
       EnumerationService.loadEnumerationByTab();
    }  
    // load data for tab click
    if($rootScope.currRel !== 'undefined' && $rootScope.currRel !== 'itself' && $scope.regionId !== 'us'){
        $scope.loadDataByTab($rootScope.currRel);
    } else if($rootScope.resourceHref !== undefined) {
        var params = {};
         resourceFactory.get($rootScope.resourceHref, params, $rootScope.headers).success(function(responseData){
            var data = responseData.data || responseData;
            if (data) {
                $scope.data=data;
                EnumerationService.executeEnumerationFromBackEnd(data, 'create');
                if($rootScope.regionId === 'us'){
                    EnumerationService.executeEnumerationFromBackEnd(data, 'fetch');    
                }
            }
        });            
    }
});