Get the current notebook data and export.

def export(self, timestamp=None):
        """
        Get the current notebook data and export.
        """
        if self._timestamp is None:
            raise Exception("No timestamp set. Has the archive been initialized?")
        if self.skip_notebook_export:
            super(NotebookArchive, self).export(timestamp=self._timestamp,
                                                info={'notebook':self.notebook_name})
            return

        self.export_success = None
        name = self.get_namespace()
        # Unfortunate javascript hacks to get at notebook data
        capture_cmd = ((r"var capture = '%s._notebook_data=r\"\"\"'" % name)
                       + r"+json_string+'\"\"\"'; ")
        cmd = (r'var kernel = IPython.notebook.kernel; '
               + r'var json_data = IPython.notebook.toJSON(); '
               + r'var json_string = JSON.stringify(json_data); '
               + capture_cmd
               + "var pycmd = capture + ';%s._export_with_html()'; " % name
               + r"kernel.execute(pycmd)")

        tstamp = time.strftime(self.timestamp_format, self._timestamp)
        export_name = self._format(self.export_name, {'timestamp':tstamp, 'notebook':self.notebook_name})
        print(('Export name: %r\nDirectory    %r' % (export_name,
                                                     os.path.join(os.path.abspath(self.root))))
               + '\n\nIf no output appears, please check holoviews.archive.last_export_status()')
        display(Javascript(cmd))