在加载时绑定ng-model中的ng-options（如双向绑定）

Question

The situation:

I have the following select:

<select ng-model="model" ng-options="o as o.name for o in options track by o.code">
    <option value="">- Default -</option>
</select>

My options datas are like this:

$scope.options = [{id: 1, code: 'foo', name: 'Foo!'}, {id: 2, code: 'bar', name: 'Bar!'}];

What I want to do:

I want to have my select with a pre-selected value. My constraint is that I only know the code attribute of my object. With the help of the track by notation I can do that simply like this:

$scope.model = {code: 'bar'};

And it works, the selected value of the select is "Bar!"

The problem:

When I send this data to my backend, I need to send the id attribute of my object. The data sent is {code: 'bar'} but not {id: 2, code: 'bar', name: 'Bar!'} as I want.

For me it is the normal behavior... because I stored in my model {code: 'bar'} and I did not change the value selected.

The conclusion:

Is there a way to tell to AngularJS to copy the value from the options list to model when there is a default value in model (when there is a match using the track by notation) ?

Info: I know that I can do something like this $scope.model = $scope.options[2] (with some logic to determine the index...) but I would like something more magical... If it is possible... :D

Answer 1

OP Info : I know that I can do something like this $scope.model = $scope.options[2] (with some logic to determine the index...) but I would like something more magical... If it is possible... :D

---

I have 3 magic's for your 3 objects

Magic 1 :

$scope.model = $scope.options.filter(function(item) {
  return item.code=== 'bar';
})[0];

Magic 2:

app.filter('getById', function() {
  return function(input, id) {
    var i=0, len=input.length;
    for (; i<len; i++) {
      if (+input[i].id == +id) {
        return input[i];
      }
    }
    return null;
  }
});

$scope.model  = $filter('getById')($scope.options, 2);

Magic 3

angular.forEach($scope.options, function(option) {
        $scope.model = option.name == "name";
        if($scope.model !=null){break}
    });

Answer 2

You need to add a ng-change on the <select> and then create a function that will look for the selected option and its corresponding JSON model. Use this

HTML

<div ng-app='app' ng-controller='mainCtrl'>
    <select ng-model="model" ng-options="o as o.name for o in options track by o.code" 
    ng-change='getValue(this)'>
    <option value="">- Default -</option>
</select>
</div>

CONTROLLER

angular.module('app',['QuickList']).controller('mainCtrl', function($scope){
   $scope.options = [{id: 1, code: 'foo', name: 'Foo!'}, {id: 2, code: 'bar', name: 'Bar!'}];
   $scope.model = {code: 'bar'};
   $scope.getValue = function(item){
      console.log($scope.selectedOption = item.model);
   }
});

Whenever you will select the option in the <select> box you will see the actual JSON object for that option printed in the console.

Here is the working JSFIDDLE