fileModel.js

app.directive('fileModel', ['$parse', function($parse){
        return{
            restrict : 'A',
            link : function(scope, element, attrs){
                var model       = $parse(attrs.fileModel);
                var modelSetter = model.assign;

                element.bind('change', function(){
                    scope.$apply(function(){
                        modelSetter(scope, element[0].files[0]);
                    });
                });
            }
        };
    }]);