Question

我有一个页面，它会调用api来返回一页的记录。这是很多信息，需要时间来加载。我试图链接承诺，以便在显示它的页面加载之前加载数据。我使用以下内容来调用第一部分：

$scope.selectAll = function () {
    alert('Please wait while your data is loaded...');
    $scope.print.sections = angular.copy($scope.sections);
    var promise = getAllSections($scope.print.sections);

    promise.then(function () {
        $scope.dataLoading = false;
        alert('Dataload complete!');
    })

};

function getAllSections(sections) {
    var deferred = $q.defer();
    deferred.notify('Getting Data');
    for (var i = 0; i < $scope.print.sections.length; i++) {
        getSectionData($scope.print.sections[i]);
    }
    deferred.resolve('Data Complete')
    return deferred.promise;
};

我的问题是函数“getSectionData”在我的服务中调用了几个函数（为简洁起见，这只是服务的一部分）：

angular.module('myModule').service('contractorService', [
     '$http', '$q', function ($http, $q) {

         this.getcompletioncertificatepage = function () {
             return $http.post('/SSQV4/SSQV5/Contractor/GetCompletionCertificate')
         };
         this.getselectedcontractorservices = function (id) {
             return $http.post('/SSQV4/SSQV5/Contractor/GetSelectedContractorServices?sectionId=' + id)
         }
         this.getavailablecontractorservices = function (id) {
             return $http.post('/SSQV4/SSQV5/Contractor/GetAvailableContractorServices?sectionId=' + id)
         };

         this.getgeneraluploadimage = function (id) {
             return $http.post('/SSQV4/SSQV5/Contractor/GetGeneralUploadDocument?imageType=' + id)
         };
         this.getemrtabulation = function () {
             return $http.post('/SSQV4/SSQV5/Contractor/GetEMRTabulationColumns')
         };

         this.getimage = function (id, docDate) {
             return $http.post('/SSQV4/SSQV5/Contractor/GetImage', {"emrDetailID": id, "docDate" : docDate})
          };
         this.getemrquestion = function () {
             return $http.post('/SSQV4/SSQV5/Contractor/GetEMRQuestion')
         };

在我的控制器中，我称之为：

       function getSectionData(section) {
            var id = section.QuestionSectionID;
                    contractorService.getIncidentColumns(clusterId)
                    .success(function (data) {
    ...}
                contractorService.getgeneralincidentquestions(id)
                .success(function (data) {
...}

    ... (there are many calls to the service here)
        }

我正在试图弄清楚如何使用服务的promises为我必须调用的每个函数并链接它们，以便我的“selectAll”函数中的“then”函数不会显示直到所有get函数已经完成。我试着把它放在servcie中：

       this.getIncidentDetailByQtr = function (id) {
     var deferred = $q.defer();
     $http.post('/SSQV4/SSQV5/Contractor/GetIncidentDetailByQtr?tabId=' + id)
     return deferred.promise;
 };

这在控制器中：

            var promise = contractorService.getIncidentDetailByQtr(7)
            .then(function (data) {
                $scope.qtrDetail = data;
                deleteTableRows($scope.qtrDetail);
            });

有效，直到我尝试向其他调用添加更多承诺（即var promiseA等）。

当我尝试这样做时：

                var promise = contractorService.getIncidentDetailByQtr(7)
                .then(function (data) {
                    $scope.qtrDetail = data;
                    deleteTableRows($scope.qtrDetail);
                });
                $scope.incidentTableDefinition = '<table>' + firstRow + secondRow + thirdRow + '<tr style="text-align:center" ng-repeat="q in qtrDetail">' + repeatRow + '</tr></table>';
                firstRow = '';
                secondRow = '';
                thirdRow = '';
                repeatRow = '';
                var promiseA = contractorService.getincidentsummarycolumns(9)
                .then(function (data) {
                    $scope.summaryColumns = data;

我收到错误“无法获取属性”，然后是“未定义或空引用”。

函数“getSelectedData”对服务进行大约15次调用。我需要初始“解决”，直到所有这些都完成后才执行。我是新手，但我很确定这与链接承诺有关，但我无法弄清楚如何在这里完成我需要的东西。非常感谢任何帮助！

Answer 1

在对＆＃34; $ q.all＆＃34;：

进行一些研究后，有以下工作

 $scope.selectAll = function () {
        alert('Please wait while your data is loaded...');
        $scope.print.sections = angular.copy($scope.sections);
        var promise = getAllSections($scope.print.sections);

        promise.then(function () {
            $scope.dataLoading = false;
            alert('Dataload complete!');
        })

    };
    function getAllSections(sections) {
        var promises = [];
        angular.forEach(sections, function (section) {
            var promise = getSectionData(section)
            promises.push(promise);
        });
        return $q.all(promises);
    }

希望这有助于其他人。快乐的编码！

Angularjs在服务中使用Promise

1 个答案: