Angular - data not available inside ng-init - angularjs

Question

Angular partial - HTML.
BaseCtrl
<div ng-controller="SelectTagCtrl">
<input type="text" ng-init="setTags(viewData['users'])" ui-select2="tagAllOptions" ng-model="tagsSelection" name="users" />
{{viewData['users']}} ECHOES CORRECTLY.
But undefined when passed inside ng-init callback.
</div>
<input type="text" class="span12" placeholder="Brief Description" name="description" value="{{viewData['description']}}">
ECHOES CORRECTLY.
Controller.js
function SelectTagCtrl(){
$scope.setTags = function(data){
// data is undfined when viewData['users'] is used. <-- PROBLEM
// correct when I pass some static string.
}
}
//POPULATING viewData to be used inside view partial.
function BaseCtrl(){
$http.get(url).success(function(data){
$scope.viewData = data.data || [];
$scope.view_type = $scope.viewData['view_type'];
$scope.fields = data.data.fields;
console.log($scope);
}).error();
}

Answer 1

Using timeout would be a workaround, instead I would take a $scope variable inside the controller to know if the ajax call has completed.
The problem is ng-init might get called before ajax completion.
I already had ui-if directive configured in my angular project, so I used it with the combination of $scope variable to get the things working.
<div ng-controller="SelectTagCtrl" ui-if="ajax_done">
<input type="text" ng-init="setTags(viewData['users'])" ui-select2="tagAllOptions" ng-model="tagsSelection" name="users" />
</div>
And inside controller,
$http.get(gurl + '.json').success(function(data,status){
// some stuff
$scope.ajax_done = true;
}).error();
Because of angular's magical two-way binding, the element will get updated. Now it sees that ajax request is completed, ui-if will get a truthy value and ng-init directive of the element will get a chance to execute its callback.
EDIT: ui-if was removed from Angular UI in favour of ng-if which is now built in.

Answer 2

Here are two different changes to your fiddle that appear to work.
Fiddle 1 - this version uses $scope.$apply(exp) as described in the documentation here and is useful when you are modifying angular bound data outside of the angular framework. In this example setTimeout is the culprit.
setTimeout(function(){
console.log("updateVal" );
$scope.$apply(function() {
$scope.updateVal2();
});
console.log($scope.tagsSelection);
},5000);
Fiddle 2 - this version uses angular's wrapper for setTimeout called the $timeout service.
$timeout(function(){
console.log("updateVal" );
$scope.updateVal2();
console.log($scope.tagsSelection);
},5000);