Dynamically assign ng-model

I'm trying to generate a set of check-boxes from an object array. I'm aiming to have the check-boxes dynamically map their ng-model to a property of the new object that will be submitted into the array.

What I had in mind is something like

<li ng-repeat="item in items">
<label>{{item.name}}</label>
<input type="checkbox" ng-model="newObject.{{item.name}}">
</li>

This doesn't work as can be seen on this JSFiddle:

http://jsfiddle.net/GreenGeorge/NKjXB/2/

Can anybody help?

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最佳答案

This should give you desired results:

<input type="checkbox" ng-model="newObject[item.name]">

Here is a working plunk: http://plnkr.co/edit/ALHQtkjiUDzZVtTfLIOR?p=preview

小开

EDIT As correctly noted in the comments using this with ng-change requires a "dummy" ng-model to be present beforehand. It should however be noted that apparently with 1.3 the required options have been provided by the framework. Please check out https://stackoverflow.com/a/28365515/3497830 below! /EDIT

Just in case you are like me stumbling over a simple case while having a more complex task, this is the solution I came up with for dynamically binding arbitrary expressions to ng-model: http://plnkr.co/edit/ccdJTm0zBnqjntEQfAfx?p=preview

Method: I created a directive dynamicModel that takes a standard angular expression, evaluates it and links the result to the scope via ng-model and $compile.

var app = angular.module('plunker', []);


app.controller('MainCtrl', function($scope) {
$scope.data = {};
$scope.testvalue = 'data.foo';
$scope.eval = $scope.$eval;
});


var app = angular.module('plunker', []);


app.controller('MainCtrl', function($scope) {
$scope.data = {};
$scope.testvalue = 'data.foo';
$scope.eval = $scope.$eval;
});


app.directive('dynamicModel', ['$compile', function ($compile) {
return {
'link': function(scope, element, attrs) {
scope.$watch(attrs.dynamicModel, function(dynamicModel) {
if (attrs.ngModel == dynamicModel || !dynamicModel) return;


element.attr('ng-model', dynamicModel);
if (dynamicModel == '') {
element.removeAttr('ng-model');
}


// Unbind all previous event handlers, this is
// necessary to remove previously linked models.
element.unbind();
$compile(element)(scope);
});
}
};
}]);

Usage is simply dynamic-model="angularExpression" where angularExpression results in a string that is used as the expression for ng-model.

I hope this saves someone the headache of having to come up with this solution.

Regards, Justus

小开

With Angular 1.3, you can use ng-model-options directive to dynamically assign the model, or bind to an expression.

Here is a plunkr: http://plnkr.co/edit/65EBiySUc1iWCWG6Ov98?p=preview

<input type="text" ng-model="name"><br>
<input type="text" ng-model="user.name"
ng-model-options="{ getterSetter: true }">

More info on ngModelOptions here: https://docs.angularjs.org/api/ng/directive/ngModelOptions

小开

This is my approach to support deeper expression, e.g. 'model.level1.level2.value'

<input class="form-control" ng-model="Utility.safePath(model, item.modelPath).value">

where item.modelPath = 'level1.level2' and Utility(model, 'level1.level2') is the utility function that returns model.level1.level2

小开 

<!DOCTYPE html>
<html>
<script src="https://ajax.googleapis.com/ajax/libs/angularjs/1.6.4/angular.min.js"></script>
<body>


<div ng-app="myApp" ng-controller="myCtrl">
<form name="priceForm" ng-submit="submitPriceForm()">
<div ng-repeat="x in [].constructor(9) track by $index">
<label>
Person \{\{$index+1}} <span class="warning-text">*</span>
</label>
<input type="number" class="form-control" name="person\{\{$index+1}}" ng-model="price['person'+($index+1)]" />


</div>
<button>Save</button>
</form>
</div>


<script>
var app = angular.module('myApp', []);
app.controller('myCtrl', function ($scope) {
$scope.price = [];
$scope.submitPriceForm = function () {
//objects be like $scope.price=[{person1:value},{person2:value}....]
console.log($scope.price);
}
});
</script>
</body>
</html>


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