Unable to http-get results into arrays for ons-lazy-repeat controller

Question

I'm using ons-lazy-repeat and trying to query from mySql. If I pre-defined the arrays it works perfectly. But I need it to be working dynamically with database hence I included httpget but it didn't work. So I tried adding alerts and realised httpget function gets called last after every other functions (configureItemScope, calculateItemHeight, countItems) are called finished.

I know I can use httpget function within configureItemScope but I will not be able to get CountItems anymore because it seems that countitem is run first before configureItemScope.

I'm so confused with using ons-lazy-repeat. And I'm a beginner with onsen-ui. Appreciate anyone to help please?

ons.bootstrap()
.controller('Ctrl', ['$scope', '$http', '$q', function($scope, $http, $q) {

    $scope.channels = [{
        name : '',
        description : '',
        category : ''
    }];

    $http.get(serviceURL + 'TestApp/services/getlist.php', {
        timeout: $scope.canceler.promise
    }).success(function(data) {
        for (i = 0; i < data.length; i = i + 1) {
            $scope.channels.push(data[index].name, data[index].description, data[index].category);
        }
    }).error(function() {

    });

    alert('scope.channels');

    $scope.query = '';
    $scope.$watch('query', function(q) {
        if ($scope.timeout) {
            $timeout.cancel($scope.timeout);
        }

        $scope.filteredChannels = $scope.channels.filter(function(channel) {
            return channel.name.toLowerCase()
                    .indexOf(q.toLowerCase()) > -1;
        });
    });

    $scope.MyDelegate = {
        configureItemScope: function(index, itemScope) {
            alert('MyDelegate');
            itemScope.name = $scope.filteredChannels[index].name;
            itemScope.description = $scope.filteredChannels[index].description;
            itemScope.category = $scope.filteredChannels[index].category;
        },
        calculateItemHeight: function(index) {
            alert('calculateItemHeight');
            return 90;
        },
        countItems: function() {
            alert('countItems');
            return $scope.filteredChannels.length;
        }
    };
}]);