generateUploadCallback: function(onUploadSuccess) {
        return function () {
            var form       = <HTMLFormElement> document.getElementById('uploadForm');
            var formData   = new FormData(form);
            // TODO: fail if the user selected more than one file

            $.ajax(
                {
                    url        : '/web/upload',
                    type       : 'POST',
                    data       : formData,
                    processData: false,
                    contentType: false,
                    cache      : false,
                    success    : onUploadSuccess,
                    error      : function (request, status, error) {
                        console.error(
                            `MOEsaic upload: ${error}\n${request.responseText}`
                        );

                        moesaic.ui.message_dialog.show(
                            'Server ERROR',
                            'Upload failed.',
                            function() {
                                // return to the default upload page
                                window.location.href = 'moesaic.html';
                            }
                        );
                    }
                }
            );
        };
    },