export default {
    // ids of the items that should be currently displayed based on
    // current list type and current pagination
    
    activeIds (state) {
      const { activeType, itemsPerPage, lists } = state
      if (!activeType) {
        return []
      }
  
      const page = Number(state.route.params.page) || 1
      const start = (page - 1) * itemsPerPage
      const end = page * itemsPerPage
  
      return lists[activeType].slice(start, end)
    },
  
    // items that should be currently displayed.
    // this Array may not be fully fetched.
    activeItems (state, getters) {
      return getters.activeIds.map(id => state.items[id]).filter(_ => _)
    }
  }