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Difficulty with ng-model, ng-repeat, and inputs

This seems to be a binding issue.

The advice is don't bind to primitives.

Your ngRepeat is iterating over strings inside a collection, when it should be iterating over objects. To fix your problem

<body ng-init="models = [{name:'Sam'},{name:'Harry'},{name:'Sally'}]">
    <h1>Fun with Fields and ngModel</h1>
    <p>names: {{models}}</p>
    <h3>Binding to each element directly:</h3>
    <div ng-repeat="model in models">
        Value: {{model.name}}
        <input ng-model="model.name">                         
    </div>

jsfiddle: http://jsfiddle.net/jaimem/rnw3u/5/


Using Angular latest version (1.2.1) and track by $index. This issue is fixed

http://jsfiddle.net/rnw3u/53/

<div ng-repeat="(i, name) in names track by $index">
    Value: {{name}}
    <input ng-model="names[i]">                         
</div>

You get into a difficult situation when it is necessary to understand how scopes, ngRepeat and ngModel with NgModelController work. Also try to use 1.0.3 version. Your example will work a little differently.

You can simply use solution provided by jm-

But if you want to deal with the situation more deeply, you have to understand:

  • how AngularJS works;
  • scopes have a hierarchical structure;
  • ngRepeat creates new scope for every element;
  • ngRepeat build cache of items with additional information (hashKey); on each watch call for every new item (that is not in the cache) ngRepeat constructs new scope, DOM element, etc. More detailed description.
  • from 1.0.3 ngModelController rerenders inputs with actual model values.

How your example "Binding to each element directly" works for AngularJS 1.0.3:

  • you enter letter 'f' into input;
  • ngModelController changes model for item scope (names array is not changed) => name == 'Samf', names == ['Sam', 'Harry', 'Sally'];
  • $digest loop is started;
  • ngRepeat replaces model value from item scope ('Samf') by value from unchanged names array ('Sam');
  • ngModelController rerenders input with actual model value ('Sam').

How your example "Indexing into the array" works:

  • you enter letter 'f' into input;
  • ngModelController changes item in names array => `names == ['Samf', 'Harry', 'Sally'];
  • $digest loop is started;
  • ngRepeat can't find 'Samf' in cache;
  • ngRepeat creates new scope, adds new div element with new input (that is why the input field loses focus - old div with old input is replaced by new div with new input);
  • new values for new DOM elements are rendered.

Also, you can try to use AngularJS Batarang and see how changes $id of the scope of div with input in which you enter.


If you don't need the model to update with every key-stroke, just bind to name and then update the array item on blur event:

<div ng-repeat="name in names">
    Value: {{name}}
    <input ng-model="name" ng-blur="names[$index] = name" />
</div>

I just updated AngularJs to 1.1.2 and have no problem with it. I guess this bug was fixed.

http://ci.angularjs.org/job/angular.js-pete/57/artifact/build/angular.js


The problem seems to be in the way how ng-model works with input and overwrites the name object, making it lost for ng-repeat.

As a workaround, one can use the following code:

<div ng-repeat="name in names">
    Value: {{name}}
    <input ng-model="names[$index]">                         
</div>

Hope it helps


I tried the solution above for my problem at it worked like a charm. Thanks!

http://jsfiddle.net/leighboone/wn9Ym/7/

Here is my version of that:

var myApp = angular.module('myApp', []);
function MyCtrl($scope) {
    $scope.models = [{
        name: 'Device1',
        checked: true
    }, {
        name: 'Device1',
        checked: true
    }, {
        name: 'Device1',
        checked: true
    }];

}

and my HTML

<div ng-app="myApp">
    <div ng-controller="MyCtrl">
         <h1>Fun with Fields and ngModel</h1>
        <p>names: {{models}}</p>
        <table class="table table-striped">
            <thead>
                <tr>
                    <th></th>
                    <th>Feature 1</td>
                    <th>Feature 2</th>
                    <th>Feature 3</th>
                </tr>
            </thead>
            <tbody>
                <tr>
                    <td>Device</td>
                   <td ng-repeat="modelCheck in models" class=""> <span>
                                    {{modelCheck.checked}}
                                </span>

                    </td>
                </tr>
                <tr>
                    <td>
                        <label class="control-label">Which devices?</label>
                    </td>
                    <td ng-repeat="model in models">{{model.name}}
                        <input type="checkbox" class="checkbox inline" ng-model="model.checked" />
                    </td>
                </tr>
            </tbody>
        </table>
    </div>
</div>