2 redux states for fetched entities and shown entities

[hyzhak]

• fetched fire evidences (update from wss and fetched directly)
• shown entities (sort, subset of fetched entities)

because we can fetch a lot of items and in different orders. Even in realtime. But playlist should reflect what actually we show to user.

[hyzhak]

• use normalized state:

{
  entities: {
    category: {
      1: {},
      2: {},
    },
    somethingElse: {}
  }
}

• use UI state

{
  entities: {},
  ui: {
    feed: {
      items: [],
      sortBy: 'date'
    }
  }
}

• get access to selectors and global state to get result of selector or state from other reducers
  I may need to modify this line https://github.com/reduxjs/redux/blob/master/src/combineReducers.js#L168 to pass global state
• another way to pass global state to reducers. To have middleware, which would add getState to all actions A concern on combineReducer, when an action is related to multiple reducers reduxjs/redux#601 (comment)
• and use this reducer on a top https://github.com/redux-utilities/reduce-reducers, because I'd like to share global state to ui slice (We don't need it in entities slice)

reduceReducers(
  combineReducers({
    entities: combineReducers({
       category1,
       category2
    })
  }),
  uiReducers({
    feeder,
    usersProfile
  })
)

uiReducers - would add global state as 3rd argument. So we be able to use selectors there or (alternative) we should just pass entities state slice and get needed data manually (problem - we may duplicate selectors there)

• ? How to deal with UI state? Are there any good redux practices?

[hyzhak]

I have decided to use redux saga for business logic.
So in sage I process incoming data and split data flow in to groups:

• entities
• ui