Redux - Additional Topics

Redux Toolkit

The makers of Redux have recognized that Redux is complicated and have introduced a “Batteries Included, Highly Opinionated” framework for making stores called the Redux Toolkit

This toolkit specifies a few different means of building a reducer and action set that work well together and are easier to understand and integrate

Ultimately, your store code can be as simple and declarative as this:

const postsSlice = createSlice({ name: ‘posts’, initialState: [], reducers: { createPost(state, action) {}, updatePost(state, action) {}, deletePost(state, action) {} } })

// Extract the action creators object and the reducer const { actions, reducer } = postsSlice // Extract and export each action creator by name export const { createPost, updatePost, deletePost } = actions // Export the reducer, either as a default or named export export default reducer

// ————— Sample Use ————– // console.log(createPost({ id: 123, title: ‘Hello World’ })) // {type : “posts/createPost”, payload : {id : 123, title : “Hello World”}}

// Notice how createSlice transforms your defiition? console.log(postsSlice) /* { name: ‘posts’, actions : { createPost, updatePost, deletePost, }, reducer } */


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Redux Toolkit package is intended to be the standard way to write Redux logic. It was originally created to help address three common concerns about Redux:

"Configuring a Redux store is too complicated"
"I have to add a lot of packages to get Redux to do anything useful"
"Redux requires too much boilerplate code"
We can't solve every use case, but in the spirit of create-react-app and apollo-boost, we can try to provide some tools that abstract over the setup process and handle the most common use cases, as well as include some useful utilities that will let the user simplify their application code.

This package is not intended to solve every possible concern about Redux, and is deliberately limited in scope. It does not address concepts like "reusable encapsulated Redux modules", data fetching, folder or file structures, managing entity relationships in the store, and so on.

That said, these tools should be beneficial to all Redux users. Whether you're a brand new Redux user setting up your first project, or an experienced user who wants to simplify an existing application, Redux Toolkit can help you make your Redux code better.

# What's Included
Redux Toolkit includes:

A configureStore() function with simplified configuration options. It can automatically combine your slice reducers, adds whatever Redux middleware you supply, includes redux-thunk by default, and enables use of the Redux DevTools Extension.
A createReducer() utility that lets you supply a lookup table of action types to case reducer functions, rather than writing switch statements. In addition, it automatically uses the immer library to let you write simpler immutable updates with normal mutative code, like state.todos[3].completed = true.
A createAction() utility that returns an action creator function for the given action type string. The function itself has toString() defined, so that it can be used in place of the type constant.
A createSlice() function that accepts a set of reducer functions, a slice name, and an initial state value, and automatically generates a slice reducer with corresponding action creators and action types.
The createSelector utility from the Reselect library, re-exported for ease of use.