How can I handle multiple queries with useInfinityQuery?

1. Separating Queries

useInfiniteQuery is a hook in the React Query library that simplifies handling infinite scrolling or pagination scenarios. When dealing with multiple queries, we typically have several strategies to organize and manage them.

First, if each query is independent, we can simply use a separate useInfiniteQuery for each query. For example, if we have two different data sources requiring infinite loading, we can create a dedicated useInfiniteQuery hook for each list.

javascript
function App() {
  const { data: list1, fetchNextPage: fetchNextList1 } = useInfiniteQuery('list1', fetchList1);
  const { data: list2, fetchNextPage: fetchNextList2 } = useInfiniteQuery('list2', fetchList2);

  return (
    <div>
      <List1 data={list1} onLoadMore={fetchNextList1} />
      <List2 data={list2} onLoadMore={fetchNextList2} />
    </div>
  );
}

2. Merging Queries

If these queries are somewhat related, we might need to combine their data for display. In this case, we can query each data source individually and then use a state management library (such as Redux or Context API) or simple React state to merge them together.

javascript
function useCombinedInfiniteQueries(queryKeys) {
  const queries = queryKeys.map(key =>
    useInfiniteQuery(key, fetchDataForKey(key))
  );

  // Merge data
  const combinedData = React.useMemo(() => {
    return queries.map(q => q.data ? q.data.pages.flat() : []).flat();
  }, [queries]);

  // Handle loading more logic
  const fetchNextPages = () => {
    queries.forEach(query => {
      if (query.hasNextPage) {
        query.fetchNextPage();
      }
    });
  };

  return { combinedData, fetchNextPages };
}

function App() {
  const { combinedData, fetchNextPages } = useCombinedInfiniteQueries(['list1', 'list2']);

  return (
    <CombinedList data={combinedData} onLoadMore={fetchNextPages} />
  );
}

3. Dependent Queries

If the second query depends on the first query's result, we can trigger the second query when the first query's data or status changes.

javascript
function DependentQueries() {
  const firstQuery = useInfiniteQuery('first', fetchFirstList);

  const secondQuery = useInfiniteQuery('second', fetchSecondList, {
    // Only enable the second query when the first query has data
    enabled: !!firstQuery.data
  });

  return (
    <div>
      <FirstList data={firstQuery.data} />
      {firstQuery.data && <SecondList data={secondQuery.data} />}
    </div>
  );
}

The above are common patterns for handling multiple infinite loading queries. Depending on specific requirements and data relationships, selecting the most appropriate approach will help maintain code manageability and performance.