Cannot read property of Undefined in do..while - usage of $broadcast and $on

Question

I am writing a simple java script function inside a controller of angularJS,

$scope.getwork = function(taskData){

    $scope.workData = workData;
    var i =0;
    do{
        var getworkQuery = CommunicationsService.getGetworkValue($scope.workData.requestId, $scope.workData.waitTime);
        getworkQuery.query({},function(resp1,$scope){
            $scope.getTaskValue=resp1;
            console.log("inside getTaskAttri ");
            console.log($scope.getTaskValue);
            console.log($scope.getTaskValue.status);
            console.log($scope.getTaskValue.errorMessage);
            i++;
        });
    }while($scope.getworkValue.status == 'processing' && i<3);

}

Here, I am getting the error,

TypeError: Cannot read property 'status' of undefined
    at Object.$scope.getTaskAttri (http://127.0.0.1:7002/vtmui/views/js/Controllers/GetWorkController.js:128:31)
    at http://127.0.0.1:7002/vtmui/views/js/Controllers/GetTaskController.js:102:24
    at http://127.0.0.1:7002/vtmui/views/lib/angular/angular-resource.js:413:30
    at wrappedCallback (http://127.0.0.1:7002/vtmui/views/lib/angular/angular.js:6995:59)
    at http://127.0.0.1:7002/vtmui/views/lib/angular/angular.js:7032:26
    at Object.Scope.$eval (http://127.0.0.1:7002/vtmui/views/lib/angular/angular.js:8218:28)
    at Object.Scope.$digest (http://127.0.0.1:7002/vtmui/views/lib/angular/angular.js:8077:25)
    at Object.Scope.$apply (http://127.0.0.1:7002/vtmui/views/lib/angular/angular.js:8304:24)
    at done (http://127.0.0.1:7002/vtmui/views/lib/angular/angular.js:9357:20)
    at completeRequest (http://127.0.0.1:7002/vtmui/views/lib/angular/angular.js:9531:7) angular.js:5930
inside getTaskAttri  GetTaskController.js:122
Resource {requestId: "2641991", status: "failure", errorMessage: "Communication failure during execution process.", waitTime: 0, workLsit: Array[0]…}
failure 
Communication failure during execution process.

console.log inside the do..while loop is getting displayed but it is showing undefined error in the while loop for the variable $scope.getworkValue.status:

while($scope.getworkValue.status == 'processing' && i<3);

Any idea how to solve this?

Welcome to the wonderful world of **async**! You can't do that. — SLaks, Dec 10 '13 at 22:20
See if this helps http://stackoverflow.com/questions/14220321/how-to-return-the-response-from-an-ajax-call — elclanrs, Dec 10 '13 at 22:20
@Slaks I understood the aysnc function. Whether there is any way to achieve my requirement. I need to make an ajax call until the $scope.getworkValue.status='processing' or maximum of 3 times. Any suggestions? — sbala_20, Dec 10 '13 at 22:27
defer each call until other completes. If conditions met in callback don't make another call — charlietfl, Dec 10 '13 at 23:38

sbala_20 · Accepted Answer · 2014-06-17T13:59:50.097

I was able to solve the problem using $broadcast and $on.Here is my solution,

$scope.getwork = function(taskData){
    $scope.workData = workData;
     var getworkQuery = CommunicationsService.getGetworkValue($scope.workData.requestId, $scope.workData.waitTime);
        getworkQuery.query({},function(resp1,$scope){
            $scope.getTaskValue=resp1;
            $rootScope.$broadcast("taskWork_received",resp1);
        });
}

  $scope.$on("taskWork_received", function(scope,taskWorkReceived){
    $scope.getWorkValue=taskWorkReceived;
    switch( $scope.getWorkValue)
    {
        case 'processing':
            getwork($scope.workData );
            break;
        default:
            alert("no response");
            break;
    }
});

Hope this might help some one. Please let me know if there is any problem in this solution. But it works fine for me.

Cannot read property of Undefined in do..while - usage of $broadcast and $on

1 Answers1