UPDATE. I think I got it to work by changing in the template to

 ngf-accept= "{{fileMask}}" 

Hi everybody,

We have a smFileUploaderDirective. In the template for that directive I use

<div class="btn btn-primary pull-left" 
                 ngf-multiple=multiFile 
                 title="@Labels.selectFile" 
                 ngf-select 
                 ngf-accept= fileMask 
                 ngf-change="$scope.filesloading=$files.length;onFileSelect($files, $event)">
                {{ uploadTitle }}
            </div>

In the script file for the directive we have

return {
            restrict: 'AE',
            transclude: false,
            scope: {
                okLabel: '@?',
                cancelLabel: '@?',
                confirmTitle: '@?',
                message: '=?',
                errorMessage: '=?',
                fileMask: '@?',
                uploadTitle:  '@?',
                onOpen: '&?',
                okAction: '&',
                disableAction: '=?',
                stopPropagation: '@',
                uploadOptions: '=',
                showDropZone: '@',
                uploadTemplate: '@?'
            },
            link: function (scope, element, attrs) {
                element.click(function (e) {
                    scope.click(e);

                });
            },
            controller: ['$scope', '$uibModal', 'Upload', 'resourceFactory', '$timeout', function ($scope, $uibModal, Upload, resourceFactory, $timeout) {
                // Set scope default values
                $scope.okLabel = $scope.okLabel || resourceFactory.getResource('Labels', 'uploadComplete');
                $scope.cancelLabel = $scope.cancelLabel || resourceFactory.getResource('Labels', 'cancel');
                $scope.title = $scope.confirmTitle || resourceFactory.getResource('Labels', 'uploadFile');
                $scope.uploadTitle = $scope.uploadTitle || resourceFactory.getResource('Labels', 'uploadFile');
                $scope.fileMask = $scope.fileMask || "'.*'";

(double quote, then single quote)

-----------------
In the HTML that uses that directive I use

file-mask="'.rdl'"

Unfortunately, it doesn't seem to work - I see no filter for rdl only. I found this https://github.com/danialfarid/ng-file-upload/issues/755 and tried the fiddle.

Do you see what may be wrong in the way I'm setting it up?

Thanks in advance.