Angularjs Dropdown OnChange Selected Text and Value

Question

I am new to AngularJS and trying to get Selected Text and Value from Dropdown. I followed a lot of tutorials with still unable to get there. SelectedValue and SelectedText are always undefined. Below is my code:

Html:

<div ng-app="SelectApp">
<div ng-controller="selectController">
    <select name="category-group" id="categoryGroup" class="form-control" ng-model="itemSelected" ng-change="onCategoryChange(itemSelected)">
        <option value="0">Select a category...</option>
        <option ng-repeat="category in categories" value="{{category.id}}"
             ng-disabled="category.disabled" ng-class="{'mainCategory' : category.disabled}">
             {{category.name}}
        </option>
     </select>
</div>

Js:

'use strict';
var app = angular.module('SelectApp', [ ]);
app.controller('selectController', ['$scope', '$window', function ($scope, $window) {

$scope.categories = [       
   { id: 1, name: "- Vehicles -", disabled: true },
   { id: 2, name: "Cars" },
   { id: 3, name: "Commercial vehicles", disabled: false },
   { id: 4, name: "Motorcycles", disabled: false },
   { id: 5, name: "Car & Motorcycle Equipment", disabled: false },
   { id: 6, name: "Boats", disabled: false },
   { id: 7, name: "Other Vehicles", disabled: false },
   { id: 8, name: "- House and Children -", disabled: true },
   { id: 9, name: "Appliances", disabled: false },
   { id: 10, name: "Inside", disabled: false },
   { id: 11, name: "Games and Clothing", disabled: false },
   { id: 12, name: "Garden", disabled: false }
];

$scope.onCategoryChange = function () {

    $window.alert("Selected Value: " + $scope.itemSelected.id + "\nSelected Text: " + $scope.itemSelected.name);

};
}]);

And one more thing, I have defined my first item as Select a category... then Why first item in Dropdown is always empty.

Below is my fiddle sample. http://jsfiddle.net/Qgmz7/136/

Answer 1

That's because, your model itemSelected captures the current value of your select drop down which is nothing but the value attribute of your option element. You have

<option ng-repeat="category in categories" value="{{category.id}}">

in your code, so in the rendered version, you'll get

<option ng-repeat="category in categories" value="0">

but you're expecting itemSelected to be your category object and any attempt to query id or other property will return undefined.

You can use ng-options with group by with little bit of change to your data or you can use normal ng-repeat, get the selectedIndex and lookup the category object from your categories list using that index. Showcasing the first approach here.

HTML

<select name="category-group" id="categoryGroup" 
        ng-model="itemSelected" ng-change="onCategoryChange(itemSelected)" 
        ng-options="category.name group by category.group for category in categories">
</select>

Updated Data

$scope.categories = [
       { id: 0, name: "Select a category..."},
       { id: 1, name: "Cars", group : "- Vehicles -" },
       { id: 2, name: "Commercial vehicles", group : "- Vehicles -" },
       { id: 3, name: "Motorcycles", group : "- Vehicles -" }
 ];

 $scope.itemSelected = $scope.categories[0];

Instead of disabled property, you can add a group property which can be used in group by.

Here' an updated Fiddle to illustrate the idea.