JavaScript Redux Observe Store Subscribe

observeStore.md

export const observeStore = (store, select, onChange) => {
  let currentState

  function handleChange() {
    const nextState = select(store.getState())

    if (nextState !== currentState) {
      currentState = nextState
      onChange(currentState)
    }
  }

  const unsubscribe = store.subscribe(handleChange)

  handleChange()

  return unsubscribe
}

const store = configureStore({
  specificState: {
    enabled: true
  }
})

// Store setup
this.store: {
  subscribe: (select, onChange) => observeStore(store, select, onChange),
  getState: store.getState,
  dispatch: store.dispatch
}

// Use it like this
this.store.subscribe(fullState => fullState.specificState, mySpecificState => {
  this.buttonEnabled = mySpecificState.enabled
})