populateInitialState<T> function

ThunkAction<SwipeFeedState<T>> populateInitialState<T>(InitialFeedState<T> state)

Hydrates the initial state from a pre-exsisting state

Implementation

ThunkAction<SwipeFeedState<T>> populateInitialState<T>(InitialFeedState<T> state){
  return (Store<SwipeFeedState<T>> store) async {

    bool loading = store.state.loading;

    if(!loading){

      store.dispatch(_SetLoadingEvent(true));

      // Ensure one element is present inside of the list
      final showItem = SwipeFeedCardState.tower();
      final placeholder = Tuple2(null, showItem);
      store.dispatch(SetItemsEvent<T>([placeholder]));
      Store<SwipeFeedCardState> lastItem = store.state.items[0].item2;

      // Old items will be empty but just a procaution
      // This will just be the null placeholder
      // The set items event seen above ensures this
      List<Tuple2<T?, Store<SwipeFeedCardState>>> oldItems = store.state.items;

      /// Generate new items
      List<Tuple2<T, Store<SwipeFeedCardState>>> items =
        List<Tuple2<T, Store<SwipeFeedCardState>>>.generate(
        state.items.length, (i) => Tuple2(state.items[i], SwipeFeedCardState.tower()));

      // Shift add new items into state
      final newState = shiftAdd(oldItems, items);

      // Show first card
      if(newState[0].item1 != null && items.isNotEmpty){
        store.dispatch(SetItemsEvent(newState));
        store.state.items[0].item2.dispatch(SetSwipeFeedCardState(SwipeCardShowState()));
      }
      else {
        /// Animate from loading card back to hide state
        lastItem.dispatch(SetSwipeFeedCardState(SwipeCardHideState()));

        /// Duration between animating back to hide state and displaying no items or connectivity
        await Future.delayed(Duration(milliseconds: 200));

        /// Set card back to hide state because no items loaded in
        lastItem.dispatch(SetSwipeFeedCardState(SwipeCardHideState(!store.state.connectivity ? store.state.connectivityError : store.state.noMoreItems)));
      }

      store.dispatch(_SetLoadingEvent(false));
    }
  };
}