ChildController.js

        // when a new profile is loaded, convert the vertices to the new data format
        $scope.$on('profileLoadedEvent', function (event) {
          ProfileVertexConverterService.convert($scope.profile.vertices).then(function (vertices) {

            // do stuff
            ModalService.close();
          });
        });

ModalService.js

    .service('ModalService', [
      '$timeout',
      '$modal',
      function ($timeout, $modal) {

        var modalInstance, isOpen = false;
        function open(header) {

          if (!isOpen) {

            modalInstance = $modal.open({
              templateUrl: 'static/views/modal-template.html',
              backdrop: 'static',
              keyboard: false,
              windowClass: 'modal-absolute-center',
              controllerAs: 'modal',
              controller: function () {
                var ctrl = this;
                ctrl.header = header || 'Please Wait...';
              }
            });
            isOpen = true;
            return modalInstance;
          }
        }

        function close() {

          if (angular.isDefined(modalInstance)) {
            modalInstance.close();
            isOpen = false;
            modalInstance = undefined;
          }
        }

        return {
          open: open,
          close: close
        }
      }
    ])

ParentController.js

        $scope.loadProfile = function (id, onSuccess) {
            $q.when(ModalService.open('Loading profile, please wait...')).then(function(){
                $scope.$broadcast('profileLoadedEvent');
            })
        }