android - SaveAllInBackground 不能根据需要在 deleteAllInBackground 内部工作

Question

SaveAllInBackground 在 deleteAllInBackground 中无法正常工作。

我正在尝试在后台使用全部保存来保存解析对象列表。为了避免表中的重复项，我正在查询已经存在的行并删除它们(如果有)然后保存新副本。因此，我在 deleteAllInBackground 的回调中调用 saveAllInBackground。

问题是这样的:

例如:如果要删除的列表包含 [a,b,c,d] 并且要上传的列表有 [a,b,c,d,e,f] 只有 [e,f] 得到解析.我将 [a,b,c,d,e,f] 传递给 saveAllInBackground 但只有 [e,f] 得到保留。

• 我缺少什么吗？怎么解决？

• 我可以使用不同的方法吗？

• 是否有更好的方法来避免重复？我不想添加beforeSave Hook 。调用 saveAll 的全部目的是减少 API 调用的次数。我想如果我使用 beforeSave，无论如何我都必须在云代码中运行一些查询。

这是我的代码

            ParseQuery query = new ParseQuery("PostChoice");

            query.fromPin();
            query.findInBackground(new FindCallback<ParseObject>() {
                @Override
                public void done(final List<ParseObject> localList, ParseException e) {
                    if (localList != null && !localList.isEmpty()) {
                        List<ParseObject> postList = new ArrayList<ParseObject>();
                        for (ParseObject object : localList) {

                            postList.add(object.getParseObject("post"));
                        }
                        ParseQuery query = new ParseQuery("PostChoice");
                        query.whereContainedIn("post", postList);
                        query.whereEqualTo("user", ParseUser.getCurrentUser());
                        query.findInBackground(new FindCallback<ParseObject>() {
                            @Override
                            public void done(List<ParseObject> parseCloudList, ParseException e) {

                                if (parseCloudList != null && !parseCloudList.isEmpty()) {
                                    ParseObject.deleteAllInBackground(parseCloudList, new DeleteCallback() {
                                        @Override
                                        public void done(ParseException e) {
               // this gets executed and rows are accordingly deleted                             
                                            ParseObject.saveAllInBackground(localList, new SaveCallback() {
                                                @Override
                                                public void done(ParseException e) {
// this gets executed but the rows are not uploaded. 
//the locallist is not empty. it contains the right data.
                                                    editor.putLong(Four.LAST_CHOICE_SYNC_TIME, System.currentTimeMillis());
                                                    editor.commit();
                                                    Log.i("SyncChoiceService", "Synced Choices");
                                                }
                                            });
                                        }
                                    });
                                }
                                else{
                                    ParseObject.saveAllInBackground(localList, new SaveCallback() {
                                        @Override
                                        public void done(ParseException e) {
                                            Log.i("SyncChoiceService", "Synced Choices");
                                            editor.putLong(Four.LAST_CHOICE_SYNC_TIME,System.currentTimeMillis());
                                            editor.commit();
                                        }
                                    });
                                }
                            }
                        });


                    }
                }
            });

Answer 1

我想出了这样的解决方案。它符合我的要求。我使用 updatedValue 并删除旧的，其余的作为整个列表更新。

ParseQuery query = new ParseQuery("PostChoice");

            query.fromPin();
            query.findInBackground(new FindCallback<ParseObject>() {
                @Override
                public void done(final List<ParseObject> localList, ParseException e) {
                    if (localList != null && !localList.isEmpty()) {

                        List<ParseObject> postList = new ArrayList<ParseObject>();
                        for (ParseObject object : localList) {

                            postList.add(object.getParseObject("post"));
                        }
                        ParseQuery query = new ParseQuery("PostChoice");
                        query.whereContainedIn("post", postList);
                        query.whereLessThan("updatedAt",System.currentTimeMillis());
                        query.whereEqualTo("user", ParseUser.getCurrentUser());
                        query.findInBackground(new FindCallback<ParseObject>() {
                            @Override
                            public void done(final List<ParseObject> parseCloudList, ParseException e) {
                                if (parseCloudList != null && !parseCloudList.isEmpty()) {
                                    ParseObject.deleteAllInBackground(parseCloudList, new DeleteCallback() {
                                        @Override
                                        public void done(ParseException e) {
                                            Log.i("SyncChoiceService", "Deleted old  Choices");

                                        }
                                    });
                                }


                                    }
                                });


ParseObject.saveAllInBackground(localList, new SaveCallback() {
        @Override
        public void done(ParseException e) {
            Log.i("SyncChoiceService", "Synced Choices");
        }
    });

                    }
                }
            });