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Using in an existing Redux App

xoid and Redux can coexist in a project without a problem. There's no requirement to get rid of Redux when xoid is added. If you're planning to gradually move away from Redux however, xoid is a good candidate to do so. For this, one thing you can do is to start managing some part of your Redux state via xoid. You can follow these steps:

Step 1: create an "omnipotent" action that has the ability to replace the Redux state​

const someExistingReducer = (state, action) => {
  switch(action.type) {
    case 'EXTERNAL_XOID_UPDATE': {
      return action.payload
    }
    ... // other `case` clauses
  }

Step 2: Create an "enhanced atom"​

This will forward subscriptions and state modifications directly to the Redux store.

import { store } from './store'

const $mediatorAtom = atom((read) => read(store.getState, store.subscribe))
$mediatorAtom.set = (payload) => store.dispatch({ type: 'EXTERNAL_XOID_UPDATE', payload })

Usually, atoms are derived from other atoms (as atom((read) => get($someAtom))). Observe how read is used with two arguments in this example. This is an additional overload that is used to consume an external (non-xoid) source. As long as the external source implements some getState & subscribe pair, it can be consumed by xoid like this. (See Deriving state from external sources)

Also, in the second line, you may see that the default set method is overriden. In xoid's terminology, atoms like these are called enhanced atoms. Overriding the default set method also will modify the update method's behavior.

Note: If a partial Redux state is desired, A selector instead of the store.getState can be used. Second argument remains same as store.subscribe.