Disabling/Pausing Queries

If you ever want to disable a query from automatically running, you can use the enabled = false option.

When enabled is false:

• If the query has cached data, then the query will be initialized in the status === 'success' or isSuccess state.
• If the query does not have cached data, then the query will start in the status === 'loading' and fetchStatus === 'idle' state.
• The query will not automatically fetch on mount.
• The query will not automatically refetch in the background.
• The query will ignore query client invalidateQueries and refetchQueries calls that would normally result in the query refetching.
• refetch returned from useQuery can be used to manually trigger the query to fetch.

function Todos() {
  const { isInitialLoading, isError, data, error, refetch, isFetching } =
    useQuery({
      queryKey: ['todos'],
      queryFn: fetchTodoList,
      enabled: false,
    })

  return (
    <div>
      <button onClick={() => refetch()}>Fetch Todos</button>

      {data ? (
        <>
          <ul>
            {data.map((todo) => (
              <li key={todo.id}>{todo.title}</li>
            ))}
          </ul>
        </>
      ) : isError ? (
        <span>Error: {error.message}</span>
      ) : isInitialLoading ? (
        <span>Loading...</span>
      ) : (
        <span>Not ready ...</span>
      )}

      <div>{isFetching ? 'Fetching...' : null}</div>
    </div>
  )
}

Permanently disabling a query opts out of many great features that TanStack Query has to offer (like background refetches), and it's also not the idiomatic way. It takes you from the declarative approach (defining dependencies when your query should run) into an imperative mode (fetch whenever I click here). It is also not possible to pass parameters to refetch. Oftentimes, all you want is a lazy query that defers the initial fetch:

The enabled option can not only be used to permanently disable a query, but also to enable / disable it at a later time. A good example would be a filter form where you only want to fire off the first request once the user has entered a filter value:

function Todos() {
  const [filter, setFilter] = React.useState('')

  const { data } = useQuery({
      queryKey: ['todos', filter],
      queryFn: () => fetchTodos(filter),
      // ⬇️ disabled as long as the filter is empty
      enabled: !!filter
  })

  return (
      <div>
        // 🚀 applying the filter will enable and execute the query
        <FiltersForm onApply={setFilter} />
        {data && <TodosTable data={data}} />
      </div>
  )
}

Lazy queries will be in status: 'loading' right from the start because loading means that there is no data yet. This is technically true, however, since we are not currently fetching any data (as the query is not enabled), it also means you likely cannot use this flag to show a loading spinner.

If you are using disabled or lazy queries, you can use the isInitialLoading flag instead. It's a derived flag that is computed from:

isLoading && isFetching

so it will only be true if the query is currently fetching for the first time.