How to use Android Jetpack Paging 3 with PHP - php

Question

I have succesfully implemented Android Pagination Library in my App,
The problem is - I dont know the proper way to use it with my PHP code as BackEnd with regards to number of items to load etc.
get_feed.php
<?php
$limit = 2;
//find out how many rows are in the table
$sql = "SELECT count(*) FROM uploads";
$result = $conn->prepare($sql);
$result->execute();
$total = $result->fetchColumn();
//total pages
$totalpages = ceil($total/$limit);
//get the current page or set a default
if (isset($_GET['page']) && is_numeric($_GET['page'])) {
// cast var as int
(int) $currentpage = $_GET['page'];
} else {
//default page num
$currentpage = 1;
}
//if current page is less than first page...
if ($currentpage < 1) {
// set current page to first page
$currentpage = 1;
}
//the offset of the list, based on current page
$offset = ($currentpage - 1) * $limit;
$stmt = "SELECT * FROM uploads ORDER by id DESC LIMIT $offset, $limit";
//I get all requiresd data, send and encode in json
echo json_encode($obj);
?>
All I want to do from this PHP code is to load 2 items at a time from the database.
Android codes
ApiService.kt
#GET(EndPoints.GET_RANDOM_FEED)
suspend fun getRandomFeed(
#Query("page") page: Int
) : PostsResponse
FeedSource.kt
class FeedSource(private val apiDataSource: ApiDataSource) : PagingSource<Int, Posts>() {
override suspend fun load(params: LoadParams<Int>): LoadResult<Int, Posts> {
return try {
//start from page 1 for undefined
val nextPage = params.key ?: 1
val response = apiDataSource.getRandomFeed(nextPage)
LoadResult.Page(
data = response.feeds,
prevKey = if (nextPage == 1) null else nextPage - 1,
nextKey = nextPage.plus(1)
)
} catch (e: Exception){
LoadResult.Error(e)
}
}
}
FeedViewModel.kt
#Singleton
class FeedViewModel constructor(private val apiDataSource: ApiDataSource) : ViewModel() {
//I want to load 10 items at first
val feeds = Pager(PagingConfig(pageSize = 10)) {
FeedSource(apiDataSource)
}.flow.cachedIn(viewModelScope)
}
As it is, All items are loaded at once. I have set up the loadState Adapter which should only show a spinner when items are loading or error as the case may be.
But right now, the spinner only shows when all item has been loaded and throws a HTTP 429 error
How do I make the app load 10 items initialy, then 2 at a time according to my PHP code?