A general-purpose reducer for React.
React Recast requires React 16.8.0 or later.
To use React Recast with your React app, install it as a dependency:
# If you use npm:
npm install react-recast
# Or if you use Yarn:
yarn add react-recastNote that both react and lodash-es are peer dependencies of this plugin that need to be installed separately.
Create a userStore.js store file and import the plugin:
import { noop } from 'lodash-es';
import { mapReducer } from 'react-recast';
import React, { createContext, useReducer, useContext } from 'react';
const initialState = null;
const StateContext = createContext(initialState);
const DispatchContext = createContext(noop);
export function useUserState() {
return useContext(StateContext);
}
export function useUserDispatch() {
return useContext(DispatchContext);
}
export function UserStoreProvider({ children }) {
const [state, dispatch] = useReducer(mapReducer, initialState);
return (
<StateContext.Provider value={state}>
<DispatchContext.Provider value={dispatch}>
{children}
</DispatchContext.Provider>
</StateContext.Provider>
);
}Instead of mutating the state directly, you specify the mutations you want to happen with plain objects called actions. Wrap the actions on the hook, similar to mapStateToProps function of the Redux.
function useUserActions() {
const userDispatch = useUserDispatch();
return {
setUser: (user) => userDispatch({
type: 'set',
payload: user
}),
updateUser: (partialUser) => userDispatch({
type: 'merge',
payload: partialUser
})
};
}You can call setUser and updateUser of useUserActions function from your component.
function ExampleComponent() {
const user = useUserState();
const { setUser, updateUser } = useUserActions();
return (
<>
<p>{user ? `Welcome! ID: ${user.id}, Name: ${user.name}` : 'You are not logged in.'}</p>
<button onClick={() => setUser({id: 1, name: 'Sanonz'})}>login</button>
<button onClick={() => updateUser({name: 'yourNewName'})}>update</button>
<button onClick={() => setUser(null)}>logout</button>
</>
);
}This is an interactive version of the code that you can play with online.
| Action | Description |
|---|---|
{type: 'set', payload: x} |
Sets the x of the object. |
{type: 'merge', payload: x} |
Deeply mix the properties of x into the object. |
It's extends mapReducer. See the base mapReducer reducer for common actions.
| Action | Description |
|---|---|
{type: 'add', payload: x} |
Appends the x to the end of this list. |
{type: 'addAll', payload: [x]} |
Appends all of the elements in the x collection to the end of this list. |
{type: 'insert', index: idx, payload: x} |
Inserts the x at the idx in this list. |
{type: 'insertAll', index: idx, payload: [x]} |
Inserts all of the [x] at the idx in this list. |
{type: 'replace', payload: {oldValue, newValue}} |
Replaces each element of this list with the result of applying the operator to that element. |
{type: 'shift'} |
Removes the first element from the list. |
{type: 'pop'} |
Removes the last element from the list. |
{type: 'remove', payload: x} |
Removes the first occurrence of the x from this list. |
{type: 'removeAll', payload: [x]} |
Removes from this list all of its elements that are contained in the [x]. |
{type: 'removeAt', index: idx} |
Removes the object at idx from this list. |
If you find a bug, please file an issue on our issue tracker on GitHub.
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