redux-toolbelt-thunk

A set of helper functions that extends redux-toolbelt for usage with redux-thunk.

TOC

- Installation
- Import
- Motivation
- Usage
+ [makeThunkAsyncActionCreator(baseName, asyncFn [,argsMapper[, options]])](#makethunkasyncactioncreatorbasename-asyncfn-argsmapper-options)
* Arguments
* Returns
* _toolbeltAsyncFnArgs
* withDefaults

Article

Read about redux-toolbelt and redux-toolbelt-thunkhere

Installation

First, you have to install the redux-thunk npm package:
``sh
npm i -S redux-thunk

or

yarn add redux-thunk
`
And add it to redux's applyMiddleware:
`
applyMiddleware(thunk)
`
More info on it's installation can be found in the package's docs.

Then install the redux-toolbelt-thunk npm package and the redux-toolbelt npm package it depends on.
`sh
npm i -S redux-toolbelt redux-toolbelt-thunk


or


yarn add redux-toolbelt redux-toolbelt-thunk
`

Import

You may import the functions you'd like to use using one of the two methods:
`js
import {makeThunkAsyncActionCreator} from 'redux-toolbelt-thunk'
// or
import makeThunkAsyncActionCreator from 'redux-toolbelt/lib/makeThunkAsyncActionCreator'

`

Motivation


makeAsyncActionCreator can be very useful to create an action creator that uses promises and reports its progress to the Redux state:
`js
// Instead of:
const fetchUser = makeAsyncActionCreator('FETCH_USER')

dispatch(fetchUser('user_01'))
fetchUserFromServer('user_01')
.then(result => dispatch(fetchUser.success(result)))
.then(error => dispatch(fetchUser.failure(error)))
`

makeThunkAsyncActionCreator replaces these with one line:

`js
const fetchUser = makeThunkAsyncActionCreator('FETCH_USER', fetchUserFromServer)
dispatch(fetchUser('user_01'))
// this dispatches the action: { type: 'FETCH_USER', payload: 'user_01' }
// calls fetchUserFromServer
// when fetchUserFromServer's resolves, it calls fetchUser.success with the result.
// if fetchUserFromServer's fails, it calls fetchUser.failure with the error.
`

Usage


#### makeThunkAsyncActionCreator(baseName, asyncFn [,argsMapper[, options]])

$3

* baseName - The name of the action, and prefixes of sub-actions created.
* asyncFn - The function to execute when the action is called. It should return a Promise. When it resolves, it will trigger the success sub-action and if it rejects it will trigger the failure action.

asyncFn will be called with the arguments passed to the action with the addition of the following arguments: {getState, dispatch, extraThunkArg}. extraThunkArg is explained here.
* argsMapper - Maps the arguments that are passed to the action to the payload that will be used on the action dispatched when action is called and the meta that will be used when both the action and it's sub-actions are called.
* options
* prefix - Defaults to ''.

Prefixes the action and sub-action name. Mostly useful with makeThunkAsyncActionCreator.withDefaults that will be described below.
* defaultMeta - Defaults to undefined.

Adds metadata to the action and sub-actions:

`js
const getUserFromServer = userId => Promise.resolve({id: userId})

const fetchUserAction = makeAsyncThunkActionCreator(
'FETCH_USER', //
getUserFromServer,
{defaultMeta: {ignore: true}}
)

fetchUserAction('01', {log: true})
// {
// type: 'FETCH_USER',
// payload: '01',
// meta: {
// debug: false,
// log: false,
// _toolbeltAsyncFnArgs: ['user_01', {log: true}]
// }
// }
`
* argsMapper - Defaults to const trivialArgsMapper = (payload, meta) => ({payload, meta})

Same as the argsMapper argument described above. The argument takes priority over the option.

* ignoreOlderParallelResolves - Defaults to false

If several promises are made before any of them resolves, you can choose to ignore older resolves and only receive the last one by passing true to this option

`js
const getUserFromServer = userId => Promise.resolve({id: userId})

const fetchUserAction = makeAsyncThunkActionCreator(
'FETCH_USER',
getUserFromServer,
{ignoreOlderParallelResolves: true}
)

fetchUserAction('01') //<-- ignore this promise
fetchUserAction('02') //<-- ignore this promise
fetchUserAction('03')
`

Promises can be ignored not only by the action name but also by meta id (helpful when sending multiple requests using the same action)

`js
const getUserFromServer = userId => Promise.resolve({id: userId})

const fetchUserAction = makeAsyncThunkActionCreator(
'FETCH_USER',
getUserFromServer,
{ignoreOlderParallelResolves: true}
)

fetchUserAction('01', {id: 'user 01'}) //<-- ignore this promise
fetchUserAction('01', {id: 'user 01'})
fetchUserAction('02', {id: 'user 02'}) //<-- ignore this promise
fetchUserAction('02', {id: 'user 02'})
`

$3

An action creator that when called and dispatched, it will:

* Dispatch an action with the type of baseName and payload and meta that are based on the arguments of the call, possibly mapped via argsMapper, if present.
* Call the asyncFn and wait on the Promise it should return.
* If it resolves, the success sub-action is dispatched with the result of the Promise.
* If it rejects, the failure sub-action is dispatched with the error of the Promise.

$3


This property is always added to the meta of every action and sub-action that are created with thunkAsyncActionCreator and reflects the arguments that it was called with.

`js
const fetchUser = makeThunkAsyncActionCreator('FETCH_USER', fetchUserFromServer)
console.log(fetchUser('00'))
// {
// type: 'FETCH_USER',
// payload: ['00'],
// meta: { _toolbeltAsyncFnArgs: ['00'] }
// }
`

$3


Creates an instance of makeThunkAsyncActionCreator with the specified options:

`js
const userMakeThunkAsyncActionCreator = makeThunkAsyncActionCreator.withDefaults({
prefix: 'USER@',
defaultMeta: {log: true},
argsMapper: (...args) => ({payload: args})
})

const fetchUser = userMakeThunkAsyncActionCreator('FETCH_USER', fetchUserFromServer)
console.log(fetchUser.TYPE)
// 'USER@FETCH_USER'

console.log(fetchUser('00'))
// {
// type: 'USER@FETCH_USER',
// payload: ['00'],
// meta: {
// log: true,
// _toolbeltAsyncFnArgs: ['00']
// }
// }

console.log(fetchUser.success({id: 'user00'}))
// {
// type: 'USER@FETCH_USER@ASYNC_SUCCESS',
// payload: {
// id: 'user00'
// },
// meta: {
// log: true,
// _toolbeltAsyncFnArgs: ['00']
// }
// }
``