Angular JS: how to stop two way binding from happening - angularjs

Question

I have a very simple script that contains angular js
<script>
var delightApp = angular.module('delightmeter', []);
delightApp.controller('delightController', function ($scope) {
$scope.delightScore = 0;
$scope.test = function () {
if (isNaN($scope.delightScore)) {
// do not bind if this happens
}
}
});
</script>
The html of the above script is
<div id="angularapp" data-ng-app="delightmeter" data-ng-controller="delightController">
<input id="Text1" type="text" data-ng-model="delightScore" />
{{delightScore}}
<input id="Button1" type="button" value="button" data-ng-click="test()"/>
</div>
As we know in angular two way binding happens whatever may be the value in $scope.delightScore it gets bound to the html page.
Is there any way to stop this binding from happening ?

Answer 1

Rather than binding to the variable directly, Bind to a function that does your check
<div id="angularapp" data-ng-app="delightmeter" data-ng-controller="delightController">
<input id="Text1" type="text" data-ng-model="delightScore" />
{{ValideDelightScore()}}
<input id="Button1" type="button" value="button" data-ng-click="test()"/>
</div>
And in your controller define:
$scope.ValideDelightScore = function () {
if (isNaN($scope.delightScore)) {
return "";
}else{
return $scope.delightScore
}
}

Answer 2

There is no way to do that because you are explicity binding the model in both scopes. And even if you could you should'n mess with the Angular life-cycle, or you are going to have a bad time.
The right way to achieve what you need is, or using solution purposed by #Shivas Jayaram, or use a filter in where you don't want to display the model if isNaN.
angular.module('myApp.filters', [])
.filter('NaNFilter', function($moment, $translate) {
return function(value) {
if(isNaN(val)) {
return '';
}
return value;
};
});
And in your template:
<div id="angularapp" data-ng-app="delightmeter" data-ng-controller="delightController">
<div>Show delightScore if !NaN: {{delightScore | NaNFilter}}</div>
<input id="Text1" type="text" data-ng-model="delightScore" />
{{delightScore}}
<input id="Button1" type="button" value="button" data-ng-click="test()"/>
</div>