'Read-only representation of this sub-form
@param value: the value returned from extract()'

def represent(self, value):

    if isinstance(value, basestring):
        data = json.loads(value)
    else:
        data = value
    if (data['data'] == []):
        return current.messages['NONE']
    resource = self.resource
    component = resource.components[data['component']]
    layout = self._layout()
    columns = self.options.get('columns')
    if columns:
        layout.set_columns(columns, row_actions=False)
    fields = data['fields']
    if ((len(fields) == 1) and self.options.get('render_list', False)):
        output = layout.render_list(component, data)
    else:
        output = layout.readonly(component, data)
    layout.set_columns(None)
    return output
