I have implementated a infinite scroller which loads data at

Question

I have implementated a infinite scroller which loads data at the end of page And it is working as expected But I also want to keep observing all loaded data for any changes from local database I don t know how to do this Any suggestion

nglauber · Answer

I think you could use LiveData Flow to observe your database or maybe Paging library once you re working with paged data Then you set this data to your Composable state using `yourLiveData observeAsState `

amar_1995 · Answer

Yes I am doing for 1st chunk of data But after the scroll down there will be 2nd chunk of data and so on I am only able to observe last chunk of data But don t know how to observe the loaded previous chunks

amar_1995 · Answer

Is there any way to observe all loaded small chunk of data using livedata or something

Timo Drick · Answer

You could add the data to a ModelList which is also observed by compose

amar_1995 · Answer

I am getting `Not in frame` error on any element updated

amar_1995 · Answer

Room database will trigger any data change if observing a list of data as livedata or flow But I am working infinite scroll to show list of data Now I am only able to observe latest chunk of data but unable to observe loaded data

molikto · Answer

As I understand your queries is paginated using for example `LIMIT` so you don t load too much data into memory and you have two query one for first page and then one for load more maybe you can use ` Query` and combine with `InvalidationTracker Observer` API instead then create your own `Observable`

molikto · Answer

the approach I was talking about is incrementally update the query result without requery the database because you know what the change is so you know how it will change the query result this can avoid requery if the dataset is very large but it is error prone to implement it manually

amar_1995 · Answer

Yes I limit the data using `LIMIT` and getting the list of data as livedata from room query

amar_1995 · Answer

Now to load more I am using same query with a dynamic limit and offset value

amar_1995 · Answer

I am using server sent events which will update room local database

amar_1995 · Answer

I want to reflect those change in ui

molikto · Answer

I think in this case the ` LiveData` is not a useful abstraction because the query doesn t conrespond to a list of items that can be directly shown to users it is better to use the two query as one off ` Query` and construct your own `LiveData` instead

amar_1995 · Answer

So you mean get a list of data not livedata from query as ` Query` and then construct my own `LiveData` of that list

amar_1995 · Answer

But the issue is how to know if any data changes is that livedata

molikto · Answer

I think you can use <https developer android com reference androidx room InvalidationTracker Observer> It seems to me that s what LiveData adapter and Observable adapter use under the hood

amar_1995 · Answer

I need to check this

amar_1995 · Answer

I am not getting how to use `InvalidationTracker Observer` Due you have any example It will be a great help