Possible to add a reducer that can read from multiple state slices?

Question

I am using createSlice to create slices of state. Let's call them sliceA and sliceB. Mostly these slices are decoupled from each other. However I would like to create one reducer in sliceA that has (read) access to both sliceA and sliceB. Is this possible?

I know I can use extraReducers to accept actions that were not defined in the slice. But I think I would still be limited (in these extra reducers) to read only sliceA, and not sliceB.

Any idea how I could create a reducer that can read from both slices?

Answer 1

By default, you can't. Each slice reducer is a standalone encapsulated function that can only see its own state.

Per the Redux FAQ entry on "How can I share state across slices?", your main options are:

• Reorganize the state tree so that all the needed state is in one place
• Use an additional "top-level reducer" to run more logic
• Put more of the relevant data into the action