Redux is a predictable state container, we use this for ESP devices.
NodeRedux evolves the ideas of Redux, which help to maintain state lua base app basically NodeMCU devices.
The whole global state of your app is stored in an object tree inside a single store. The only way to change the state tree is to create an action, an object describing what happened, and dispatch it to the store. To specify how state gets updated in response to an action, you write pure reducer functions that calculate a new state based on the old state and the action.
local redux = require('redux') -- optional line for nodemcu, only need for lua app
-- This is a reducer - a function that takes a current state value and an
-- action object describing "what happened", and returns a new state value.
-- A reducer's function signature is: (state, action) => newState
--
-- The NodeRedux state should contain only plain Lua table.
-- The root state value is usually an table. It's important that you should
-- not mutate the state table, but return a new table if the state changes.
--
-- You can use any conditional logic you want in a reducer. In this example,
-- we use a if statement, but it's not required.
local function counterReducer(state, action)
state = state or { value = 0 }
if action.type == 'counter/incremented' then
return { value = state.value + 2 }
elseif action.type == 'counter/decremented' then
return { value = state.value - 1 }
else
return state
end
end
redux.createStore(counterReducer)
local function console(pState, cState)
print('Previous State: '.. pState.value, 'Current State: '.. cState.value)
end
redux.store.subscribe(console)
redux.store.dispatch({type = 'counter/incremented'})
-- {value = 1}
redux.store.dispatch({type = 'counter/incremented'})
-- {value = 2}
redux.store.dispatch({type = 'counter/decremented'})
-- {value = 1}