AngularJS ng-model-options getter-setter

user2717436 picture user2717436 · Jan 13, 2015 · Viewed 32.4k times · Source

I've just upgrade to angular version 1.3.8.

When using 1.2.23 version I've created a directive to convert the data form view to model and vice verse.

This is my directive:

.directive('dateConverter', ['$filter', function ($filter) {

    return {

        require: 'ngModel',

        link: function (scope, element, attrs, ngModelController) {

            // Convert from view to model
            ngModelController.$parsers.push(function (value) {
                return $filter('date')(new Date(date), 'yyyy-MM-ddTHH:mm:ss')
            });

            // Convert from model to view
            ngModelController.$formatters.push(function (datetime) {
                return $filter('date')(datetime, 'MM/dd/yyyy');
            });
        }
    };
}]);

});

I see here that getters and setters in binding are now supported, but I cannot find anywhere how to use both getters and setters. Is there any way to do it? That is - can ng-model-options replace my convert directive?

Thanks

Answer

Dragos Rusu picture Dragos Rusu · Jan 29, 2015

The documentation might seem a bit fuzzy but the usage is quite simple. What you need to do:

  1. HTML:

    <input ng-model="pageModel.myGetterSetterFunc"
    ng-model-options=" {getterSetter: true }">
    
  2. in JS controller, instead of the actual model, create a function that will return the value (+ apply stripping) if the there is no parameter sent and that will update the model (+ apply other changes) if a parameter is sent.

The getter/setters is basically another "layer" between the view value and model value.

Example:

$scope.pageModel.firstName = '';
$scope.pageModel.myGetterSetterFunc: function (value) {
  if (angular.isDefined(value)) {
    $scope.pageModel.firstName = value + '...';
  } else {        
    return $scope.pageModel.firstName.substr(0,
      $scope.pageModel.firstName.lastIndexOf('...')
    );
  }
}

DEMO PLUNKER: http://plnkr.co/edit/Zyzg6hLMLlOBdjeW4TO0?p=preview

(check console - http://screencast.com/t/3SlMyGnscl)

NOTE: It would be interesting to see how would this scale in terms of reusability. I would advise to create these getter/setters as externalized reusable methods and have generators for them (because the data model is different for each case). And in controllers to only call those generators. Just my 2 cents.