Conditional “multiple” attribute in <input type=“file”> with AngularJS

Question

I need an upload form field that may or may not allow the user to select more than one file.

I know I can do something like:

Answer 1

The easiest way is to write your own ngMultiple directive.

HTML (relevant):

 Allow multiple

JS:

angular
    .module('app', [])
    .controller('appCtrl', function($scope) {
        $scope.allowMultiple = false;
    })
    .directive('ngMultiple', function () {
        return {
            restrict: 'A',
            scope: {
                ngMultiple: '='
            },
            link: function (scope, element) {
                var unwatch = scope.$watch('ngMultiple', function (newValue) {
                    if(newValue) {
                        element.attr('multiple', 'multiple');
                    } else {
                        element.removeAttr('multiple');
                    }
                });
            }
        };
    });

Plunker