Mawg Mawg - 1 year ago 59
AngularJS Question

AngularJS combo box selection is not updating model

I am getting an array by AJAX, which looks like this

0: Object event_id: "1"title: "Event one" __proto__: Object
1: Object event_id: "2"title: "Event two" __proto__: Objectlength:
2__proto__: Array[0]

So, an array of JSON, with each entry having an
and a

I want to display a drop down combo box with each of the titles, and store the user selected

My HTML is

<select ng-model="analyticEvent" ng-options="x.title for x in eventNameData"

I initialize the model, when I receive the JSON data, with

if (! $scope.eventNameData)

if ($scope.selectedEventId == -1)
$scope.selectedEventId = $scope.eventNameData[0]['event_id'];
$scope.analyticEvent = $scope.eventNameData[0];

and handle the selection changing with

$scope.SelectedAnalyticEventChanged = function()
$scope.selectedEventId = $scope.analyticEvent.event_id;

but, when I breakpoint that, the value of the model,
never changes.

HOWEVER, when I add
analyticEvent == {{analyticEvent}}
to my HTML, just before the combo box, that is updated when I select from the combo box.

What am I doing wrongly? How do I get the value of the
of the selected object into

[Update] Googling, I see some remarks about
child scope
- could that be it?

[Update++] I think I should stress more that if display
in my HTML, then it is getting updated correctly - even though it doesn't get updated in the
function - how can that be?

Answer Source

Aha! It was a child scope problem.

Change the html to

<select ng-model="" ng-options="event as event.title 
        for event in eventNameData"   ng-change="SelectedAnalyticEventChanged()">

and the intialzation code to

$scope.analyticEventDummyData = {"event_id" : -1,
                                 "title" : ''};
$scope.analyticEvent = {"data" : $scope.analyticEventDummyData};

at the start of the controller, and do this when the JSON is received

                if (! $scope.eventNameData)

                if ($scope.selectedEventId == -1)
                    $scope.selectedEventId = $scope.eventNameData[0]['event_id'];
                    $ = $scope.eventNameData[0];

and the ng-change code becomes

$scope.SelectedAnalyticEventChanged = function()
    $scope.selectedEventId = $;

and we see the correct value in that function:

    event_id: "2"
    title: "Event two"
   __proto__: Object

Quod erat demomstrandum :-)

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