clear method
清空关联对象
Implementation
Future<bool> clear() async {
if (object.objectId.isEmpty) throw Exception('object objectId is empty');
if (list.isEmpty) return true;
var data = await BmobNetHelper.init().put(
'/1/classes/${object.getBmobTabName()}/${object.objectId}',
body: {key: _removeJson(list)},
);
if (data != null && data.containsKey('updatedAt')) {
list.clear();
return true;
}
return false;
}