'Retrieve update information (metadata) of the latest data file from a
specified server.
.. note:: This method is the slot responses to the signal from
ButtonCheck widget while the button is clicked.'

def on_CheckUpdate_clicked(self):

    if (self.choice != [[], []]):
        self.refresh_func_list()
        self.set_update_click_btns()
    if ((self._update == {}) or (self._update['version'] == unicode(_translate('Util', '[Error]', None)))):
        self.check_update()
