Tips for keeping your ng-model synced with ng-options in AngularJS

Question

Tips for keeping your ng-model synced with ng-options in AngularJS

Having trouble updating my model when I choose an option.

Below is my view code:

<select data-ng-model="period" ng-options="item.value as item.text for item in periodOptions"></select>

In my controller.js, this is what I have :

$scope.periodOptions = [
            { text: "This week", value: 'week' },
            { text:"This month", value: 'month '},
            { text:"This year",  value: 'year' }, 
            { text:"All times",  value: 'all-time '}
        ];

$scope.Search = function () {

            return $http({
                url: '/api/get',
                method: 'GET',
                params: {
                    period: $scope.period
                }
            }).then(function(response) {
                console.log(response);
            }, function(reason) {
                alert(reason);
            });
        };

The problem is that $scope.period does not update with the selected option from the User. Can't seem to figure out why after spending many hours on this issue.

javascript angularjs

Answer 1

Answer №1

After encountering a problem where ng-model was not updating, I discovered that the issue stemmed from having my select element nested within an element with ng-if.

<div class="editor-panel" ng-if="editorEnabled">
    ...
    <select ng-options="item as item.description for item in items" ng-model="selectedItem"/>
    ...
</div>

The use of ng-if created another scope, causing ng-model to reference a variable in this new child scope instead of the desired one.

To resolve the issue, I altered ng-model="selectedItem" to ng-model="$parent.selectedItem

Answer 2

After encountering a problem where ng-model was not updating, I discovered that the issue stemmed from having my select element nested within an element with ng-if.

<div class="editor-panel" ng-if="editorEnabled">
    ...
    <select ng-options="item as item.description for item in items" ng-model="selectedItem"/>
    ...
</div>

The use of ng-if created another scope, causing ng-model to reference a variable in this new child scope instead of the desired one.

To resolve the issue, I altered ng-model="selectedItem" to ng-model="$parent.selectedItem

Answer 3

Answer №2

Check out the note in angularjs documentation for select.
- "Note: ngModel compares by reference, not value. Make sure to keep this in mind when binding to an array of objects. Take a look at this example in the jsfiddle link provided."
You can find a similar solution to yours in this fiddle.

Here is a slightly modified solution that should work (just changed your existing code to use

ng-options="item as item.text ...

instead of

ng-options="item.value as item.text

). I hope this helps!

var myCtrl = function($scope){
  
  $scope.periodOptions = [
            { text: "This week", value: 'week' },
            { text:"This month", value: 'month '},
            { text:"This year",  value: 'year' }, 
            { text:"All times",  value: 'all-time '}
        ];
  
$scope.Search = function () {
alert('will call api with period: '+$scope.period.text);
  /*
            return $http({
                url: '/api/get',
                method: 'GET',
                params: {
                    period: $scope.period
                }
            }).then(function(response) {
                console.log(response);
            }, function(reason) {
                alert(reason);
            });
            */
        };
  
  }

<script src="https://ajax.googleapis.com/ajax/libs/angularjs/1.2.23/angular.min.js"></script>
<div ng-app ng-controller="myCtrl">
<select data-ng-model="period" ng-options="item as item.text for item in periodOptions" ng-change="updatePeriod()"></select>
  <div>{{period}} </div>
  <button ng-click='Search()' >Search</button>
  </div>

Answer 4

Check out the note in angularjs documentation for select.
- "Note: ngModel compares by reference, not value. Make sure to keep this in mind when binding to an array of objects. Take a look at this example in the jsfiddle link provided."
You can find a similar solution to yours in this fiddle.

Here is a slightly modified solution that should work (just changed your existing code to use

ng-options="item as item.text ...

instead of

ng-options="item.value as item.text

). I hope this helps!

var myCtrl = function($scope){
  
  $scope.periodOptions = [
            { text: "This week", value: 'week' },
            { text:"This month", value: 'month '},
            { text:"This year",  value: 'year' }, 
            { text:"All times",  value: 'all-time '}
        ];
  
$scope.Search = function () {
alert('will call api with period: '+$scope.period.text);
  /*
            return $http({
                url: '/api/get',
                method: 'GET',
                params: {
                    period: $scope.period
                }
            }).then(function(response) {
                console.log(response);
            }, function(reason) {
                alert(reason);
            });
            */
        };
  
  }

<script src="https://ajax.googleapis.com/ajax/libs/angularjs/1.2.23/angular.min.js"></script>
<div ng-app ng-controller="myCtrl">
<select data-ng-model="period" ng-options="item as item.text for item in periodOptions" ng-change="updatePeriod()"></select>
  <div>{{period}} </div>
  <button ng-click='Search()' >Search</button>
  </div>

Answer 5

Answer №3

give this a shot

<div ng-controller="MyCtrl">
    <select data-ng-model="period" ng-options="item.value as item.text for item in periodOptions"></select>
    <span>the value of the period is {{period}}!</span>
</div>

Answer 6

give this a shot

<div ng-controller="MyCtrl">
    <select data-ng-model="period" ng-options="item.value as item.text for item in periodOptions"></select>
    <span>the value of the period is {{period}}!</span>
</div>

Answer 7

Answer №4

The implementation of select and ngOptions is accurate. However, it appears that there is a desire for the $scope.Search function to be invoked upon every option change. To achieve this, it is necessary to establish an ngChange handler:

<select ng-model="period" 
        ng-options="item.value as item.text for item in periodOptions"
        ng-change="Search()">
</select>

Answer 8

The implementation of select and ngOptions is accurate. However, it appears that there is a desire for the $scope.Search function to be invoked upon every option change. To achieve this, it is necessary to establish an ngChange handler:

<select ng-model="period" 
        ng-options="item.value as item.text for item in periodOptions"
        ng-change="Search()">
</select>

Tips for keeping your ng-model synced with ng-options in AngularJS

Answer №1

Answer №2

Answer №3

Answer №4

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