redux-lua

Originally, redux is a predictable state container for JavaScript apps. From now on, all the redux features are available on your Lua projects. Try it out! :-D

Install

redux-lua can be installed using LuaRocks:

$ luarocks install redux-lua

Usage

Here is an example of profile updating. To handle redux state changes, it is recommended to use redux-props. To get more usages, please checkout examples.

Define actions

--[[
    actions/profile.lua
--]]
local actions = {}

function actions.updateName(name)
    return {
        type = "PROFILE_UPDATE_NAME",
        name = name
    }
end

function actions.updateAge(age)
    return {
        type = "PROFILE_UPDATE_AGE",
        age = age
    }
end

function actions.remove()
    return {
        type = "PROFILE_REMOVE"
    }
end

function actions.thunkCall()
    return function (dispatch, state)
        return dispatch(actions.remove())
    end
end

return actions

Define reducer

--[[
    reducers/profile.lua
--]]
local assign = require 'redux.helpers.assign'
local Null = require 'redux.null'

local initState = {
    name = '',
    age = 0
}

local handlers = {
    ["PROFILE_UPDATE_NAME"] = function (state, action)
        return assign(initState, state, {
            name = action.name
        })
    end,
    
    ["PROFILE_UPDATE_AGE"] = function (state, action)
        return assign(initState, state, {
            age = action.age
        })
    end,
    
    ["PROFILE_REMOVE"] = function (state, action)
        return Null
    end,
}

return function (state, action)
    state = state or Null
    local handler = handlers[action.type]
    if handler then
        return handler(state, action)
    end
    return state
end

Combine reducers

--[[
    reducers/index.lua
--]]
local combineReducers = require 'redux.combineReducers'
local profile = require 'reducers.profile'

return combineReducers({
    profile = profile
})

Create store

--[[
    store.lua
--]]
local createStore = require 'redux.createStore'
local reducers = require 'reducers.index'

local store = createStore(reducers)

return store

Create store with middlewares

Here is an example about how to define a middleware.

--[[
    middlewares/logger.lua
--]]
local Logger = require 'redux.utils.logger'

local function logger(store)
    return function (nextDispatch)
        return function (action)
            Logger.info('WILL DISPATCH:', action)
            local ret = nextDispatch(action)
            Logger.info('STATE AFTER DISPATCH:', store.getState())
            return ret

        end
    end
end

return logger

Compose all defined middlewares to middlewares array.

--[[
    middlewares/index.lua
--]]
local logger = require 'middlewares.logger'
local thunk = require 'middlewares.thunk'

local middlewares = {
    thunk,
    logger,
}

return middlewares

Finally, pass middlewares to applyMiddleware, which is provided as an enhancer to createStore, and create our store instance.

--[[
    store.lua
--]]
local createStore = require 'redux.createStore'
local reducers = require 'reducers.index'
local applyMiddleware = require 'redux.applyMiddleware'
local middlewares = require 'middlewares.index'

local store = createStore(reducers, applyMiddleware(table.unpack(middlewares)))

return store

Dispatch & Subscription

--[[
    main.lua
--]]
local ProfileActions = require 'actions.profile'
local inspect = require 'redux.helpers.inspect'
local store = require 'store'

local function callback()
    print(inspect(store.getState()))
end

-- subscribe dispatching
local unsubscribe = store.subscribe(callback)

-- dispatch actions
store.dispatch(ProfileActions.updateName('Jack'))
store.dispatch(ProfileActions.updateAge(10))
store.dispatch(ProfileActions.thunkCall())

-- unsubscribe
unsubscribe()

Debug mode

redux-lua is on Debug mode by default. Messages with errors and warnings will be output when Debug mode is on. Use following code to turn it off.

local Env = require 'redux.env'

Env.setDebug(false)

Null vs. nil

nil is not allowed as a reducer result. If you want any reducer to hold no value, you can return Null instead of nil.

local Null = require 'redux.null'

License

MIT License