Use angular's $timeout
service instead of setTimeout:
myApp.controller('parent',['$scope','$timeout', function($scope, $timeout) {
$scope.items = [
{'id':1},
{'id':2},
{'id':3},
{'id':4}
];
$scope.items.push({'id':10});
$scope.myfun = function() {
$timeout(function(){
$scope.items.push({'id':20});
alert("inserting 20....!");
},3000);
}
$scope.myfun();
}]);