React native + redux-persist: how to ignore keys (blacklist)? - javascript

I'm storing my settings with redux-persist and would like to ignore some of them to have them reset on every restart, e.g. after a crashing.
It's possible to add an array of reducer-names as blacklist or whitelist, but I'd like to ignore specific keys, e.g. settings.isLoggedIn instead of settings.
// ...
function configureStore(initialState) {
const store = createStore(
RootReducer,
initialState,
enhancer
);
persistStore(store, {
storage: AsyncStorage,
blacklist: ['router', 'settings'] // works, 'settings.isLoggedIn' doesn't.
}, () => {
// restored
});
return store;
}
// ...
Do I have to create another reducer or does anyone a solution to this problem?
Thanks in advance!

As per the documentation, the blacklist parameter contains: 'keys (read: reducers) to ignore', so I am afraid it is not possible to implement the behaviour that you want. You can try and implement that functionality yourself, but I think the codebase of the package is really focused on blacklisting reducers instead of properties (see this). I am afraid that the only solution is to create a separate reducer for your non-persistent keys (in my experience it is not much of a hassle).

Use transforms for save separate fields, for example for username in redux-form MyForm inside state.form.MyForm:
const formName = `MyForm`
const formTransform = createTransform(
(inboundState, key) => {
return {
...inboundState,
[formName]: {
values: {
username: _.get(inboundState, `${ MyForm }.values.username`)
}
}
}
},
(outboundState, key) => {
return outboundState
},
{ whitelist: [`form`] }
)
persistStore(store, {
whitelist: [
`form`
],
transforms: [
formTransform
]
})

You can use Nested Persists for this.
import { persistStore, persistReducer } from 'redux-persist';
const rootPersistConfig = {
key: 'root',
storage: storage,
blacklist: ['auth']
}
// here you can tell redux persist to ignore loginFormData from auth reducer
const authPersistConfig = {
key: 'auth',
storage: storage,
blacklist: ['loginFormData']
}
// this is your global config
const rootReducer = combineReducers({
auth: persistReducer(authPersistConfig, authReducer),
other: otherReducer,
})
// note: for this to work, your authReducer must be inside blacklist of
// rootPersistConfig
const myReducerConfig = {
key: "cp",
storage: storage,
blacklist: ["authReducer"],
debug: true
};

you have to create reducer for every prop you want to save.

A simple solution is to save the whole reducer in the whitelist and after in the reducer using 'persist/REHYDRATE' action to filter only the keys that you want to keep.
Example:
// configureStore.js
const persistConfig = {
keyPrefix: 'webapp',
whitelist: ['filters'],
}
// filtersReducer.js
const projectsBase = {
[KEYS.SORT]: PROJECTS_SORT_TYPE.NAME,
[KEYS.TEXT]: '',
}
const itemsBase = {
[KEYS.SORT]: ITEMS_SORT_TYPE.INDEX,
[KEYS.TEXT]: '',
}
const base = {
[KEYS.PROJECTS]: projectsBase,
[KEYS.ITEMS]: itemsBase
}
export const filters = (state = base, action) => {
const { type } = action
switch (type) {
case PERSIST_REHYDRATE_ACTION_TYPE: {
if (action.payload.filters) {
const filters = action.payload.filters
const projectsSort = _.get(filters, [KEYS.PROJECTS, KEYS.SORT])
const itemsSort = _.get(filters, [KEYS.ITEMS, KEYS.SORT])
const newBase = { ...base,
[KEYS.PROJECTS]: {
[KEYS.SORT]: projectsSort
},
[KEYS.ITEMS]: {
[KEYS.SORT]: itemsSort
}}
state = newBase
}
}
break
default:
break
}
return state
}

As #martinarroyo mentioned to create a separate reducer which is a good option and if we follow it and create a seperate reducer for errors, we can simply return an empty state as the default;
const initialState = {
error: null
}
export default errorReducer = (state = initialState, action) => {
switch (action.type) {
...
default:
return {
...state,
error: null
}
}
}
This will clear the state everytime we visit the site as defualt is setting the errors to null.

Related

Redux-toolkit + Signalr

What is the best way to update the state with signalr? At this moment I dispatching data inside on method callback and accessing it using useSelector inside other component.
I wonder if this is the optimal approach.
useEffect(()=> {
const connection = $.hubConnection("http://x.x.x.x/signalr", { useDefaultPath: false })
const proxy = connection.createHubProxy("exampleHub")
proxy.on("action", function(data) {
dispatch(setStatus(data))
}
})
Slice.js:
export const monitorSlice = createSlice({
name: "example",
initialState: {
status: {},
},
reducers: {
setStatus(state, {payload}) => {
state.status = payload
}
}
});
Your approach will work,
Here is other approach that you can have:
Using your own middleware
Another approach that is more agnostic is to use a middleware
import { Middleware } from 'redux'
import { monitorActions } from './monitorSlice';
const monitorMiddleware: Middleware = store => next => action => {
if (!monitorActions.startConnecting.match(action)) {
return next(action);
}
const connection = $.hubConnection("http://x.x.x.x/signalr", { useDefaultPath: false })
const proxy = connection.createHubProxy("exampleHub")
proxy.on("action", function(data) {
dispatch(setStatus(data))
});
next(action);
}
export default monitorMiddleware;
Then inside your react app when you want to establish the connection
useEffect(()=> {
dispatch(monitorActions.startConnecting())
}, [])
Then when you setup your store, do not forget to add your new middleware monitorMiddleware:
export const store = configureStore({
reducer: rootReducer,
middleware: (getDefaultMiddleware) => {
return getDefaultMiddleware().concat([monitorMiddleware])
},
});
Using create api
Another approach is to use createApi.

How to set my state from vuex to it's "original" form? [duplicate]

My state in vuex store is huge.
Is there a way to reset all the data in state in one go, instead of manually setting everything to null?
I have just found the great solution that works for me.
const getDefaultState = () => {
return {
items: [],
status: 'empty'
}
}
// initial state
const state = getDefaultState()
const actions = {
resetCartState ({ commit }) {
commit('resetState')
},
addItem ({ state, commit }, item) { /* ... */ }
}
const mutations = {
resetState (state) {
// Merge rather than replace so we don't lose observers
// https://github.com/vuejs/vuex/issues/1118
Object.assign(state, getDefaultState())
}
}
export default {
state,
getters: {},
actions,
mutations
}
Thanks to Taha Shashtari for the great solution.
Michael,
Update after using the below solution a bit more
So it turns out that if you use replaceState with an empty object ({}) you end up bricking reactivity since your state props go away. So in essence you have to actually reset every property in state and then use store.replaceState(resetStateObject). For store without modules you'd essentially do something like:
let state = this.$store.state;
let newState = {};
Object.keys(state).forEach(key => {
newState[key] = null; // or = initialState[key]
});
this.$store.replaceState(newState);
Update (from comments): What if one needs to only reset/define a single module and keep the rest as they were?
If you don't want to reset all your modules, you can just reset the modules you need and leave the other reset in their current state.
For example, say you have mutliple modules and you only want to reset module a to it's initial state, using the method above^, which we'll call resetStateA. Then you would clone the original state (that includes all the modules before resetting).
var currentState = deepClone(this.state)
where deepClone is your deep cloning method of choice (lodash has a good one). This clone has the current state of A before the reset. So let's overwrite that
var newState = Object.assign(currentState, {
a: resetStateA
});
and use that new state with replaceState, which includes the current state of all you modules, except the module a with its initial state:
this.$store.replaceState(newState);
Original solution
I found this handy method in Vuex.store. You can clear all state quickly and painlessly by using replaceState, like this:
store.replaceState({})
It works with a single store or with modules, and it preserves the reactivity of all your state properties. See the Vuex api doc page, and find in page for replaceState.
For Modules
IF you're replacing a store with modules you'll have to include empty state objects for each module. So, for example, if you have modules a and b, you'd do:
store.replaceState({
a: {},
b: {}
})
You can declare an initial state and reset it to that state property by property. You can't just do state = initialState or you lose reactivity.
Here's how we do it in the application I'm working on:
let initialState = {
"token": null,
"user": {}
}
const state = Vue.util.extend({}, initialState)
const mutations = {
RESET_STATE(state, payload) {
for (let f in state) {
Vue.set(state, f, initialState[f])
}
}
}
I am not sure what you use case is, but I had to do something similar. When a user logs out, I want to clear the entire state of the app - so I just did window.reload. Maybe not exactly what you asked for, but if this is why you want to clear the store, maybe an alternative.
If you do a state = {}, you will remove the reactivity of the properties and your getters mutations will suddenly stop working.
you can have a sub-property like:
state: {
subProperty: {
a: '',
lot: '',
of: '',
properties: '',
.
.
.
}
}
Doing a state.subProperty = {} should help, without losing the reactivity.
You should not have a state too big, break them down to different modules and import to your vuex store like so:
import Vue from 'vue'
import Vuex from 'vuex'
import authorization from './modules/authorization'
import profile from './modules/profile'
Vue.use(Vuex)
export const store = new Vuex.Store({
modules: {
authorization,
profile
}
})
now in your individual files:
// modules/authorization.js
import * as NameSpace from '../NameSpace'
import { someService } from '../../Services/something'
const state = {
[NameSpace.AUTH_STATE]: {
auth: {},
error: null
}
}
const getters = {
[NameSpace.AUTH_GETTER]: state => {
return state[NameSpace.AUTH_STATE]
}
}
const mutations = {
[NameSpace.AUTH_MUTATION]: (state, payload) => {
state[NameSpace.AUTH_STATE] = payload
},
}
const actions = {
[NameSpace.ASYNC_AUTH_ACTION]: ({ commit }, payload) => {
someService.login(payload.username, payload.password)
.then((user) => {
commit(NameSpace.AUTH_MUTATION, {auth: user, error: null})
})
.catch((error) => {
commit(NameSpace.AUTH_MUTATION, {auth: [], error: error})
})
}
}
export default {
state,
getters,
mutations,
actions
}
If you should want to clear the state you can just have a mutation implement:
state[NameSpace.AUTH_STATE] = {
auth: {},
error: null
}
Here's a solution that works in my app. I created a file named defaultState.js.
//defaultState.js
//the return value is the same as that in the state
const defaultState = () => {
return {
items: [],
poles: {},
...
}
}
export default defaultState
And then Where you want to use it
//anywhere you want to use it
//for example in your mutations.js
//when you've gotten your store object do
import defaultState from '/path/to/defaultState.js'
let mutations = {
...,
clearStore(state){
Object.assign(state, defaultState())
},
}
export default mutations
Then in your store.js
import Vue from 'vue';
import Vuex from 'vuex';
import actions from './actions';
import getters from './getters';
import mutations from './mutations'; //import mutations
import state from './state';
Vue.use(Vuex);
export default new Vuex.Store({
actions,
mutations,
state,
getters,
});
and That's it
If you want to reset your entire state you can use the built in replaceState method.
Given a state set in index.js:
const state = { user: '', token: '', products: [] /* etc. */ }
const initialStateCopy = JSON.parse(JSON.stringify(state))
export const store = new Vuex.Store({ state, /* getters, mutations, etc. */ })
export function resetState() {
store.replaceState(initialStateCopy)
}
Then in your vue component (or anywhere) import resetState:
import { resetState } from '#/store/index.js'
// vue component usage, for example: logout
{
// ... data(), computed etc. omitted for brevity
methods: {
logout() { resetState() }
}
}
Based on these 2 answers (#1 #2) I made a workable code.
My structure of Vuex's index.js:
import Vue from 'vue'
import Vuex from 'vuex'
import createPersistedState from 'vuex-persistedstate'
import { header } from './header'
import { media } from './media'
Vue.use(Vuex)
const store = new Vuex.Store({
plugins: [createPersistedState()],
modules: {
header,
media
}
})
export default store
Inside each module we need to move all states into separated var initialState and in mutation define a function resetState, like below for media.js:
const initialState = () => ({
stateOne: 0,
stateTwo: {
isImportedSelected: false,
isImportedIndeterminate: false,
isImportedMaximized: false,
isImportedSortedAsc: false,
items: [],
stateN: ...
}
})
export const media = {
namespaced: true,
state: initialState, // <<---- Our States
getters: {
},
actions: {
},
mutations: {
resetState (state) {
const initial = initialState()
Object.keys(initial).forEach(key => { state[key] = initial[key] })
},
}
}
In Vue component we can use it like:
<template>
</template>
<script>
import { mapMutations } from 'vuex'
export default {
name: 'SomeName',
data () {
return {
dataOne: '',
dataTwo: 2
}
},
computed: {
},
methods: {
...mapMutations('media', [ // <<---- define module
'resetState' // <<---- define mutation
]),
logout () {
this.resetState() // <<---- use mutation
// ... any code if you need to do something here
}
},
mounted () {
}
} // End of 'default'
</script>
<style>
</style>
Call router.go() or this.$router.go()
That will refresh the page and your state will be reset to how it was when the user first loaded the app.
Myself has read above and implemented a solution. could help you as well!!
All objects stored in Vue act as an observable. So if reference of a value is changed/mutated it triggers the actual value to be changed too.
So, Inorder to reset the state the initial store modules has to be copied as a value.
On logging out of an user, the same value has to be assigned for each modules as a copy.
This can be achieved as following:
Step 1: Create a copy of your initial module.
// store.ts
// Initial store with modules as an object
export const initialStoreModules = {
user,
recruitment,
};
export default new Vuex.Store({
/**
* Assign the modules to the store
* using lodash deepClone to avoid changing the initial store module values
*/
modules: _.cloneDeep(initialStoreModules),
mutations: {
// reset default state modules by looping around the initialStoreModules
[types.RESET_STATE](state: any) {
_.forOwn(initialStoreModules, (value: IModule, key: string) => {
state[key] = _.cloneDeep(value.state);
});
},
}
});
Step 2: Call the action to mutate the state to initial state.
// user_action.ts
const logout = ({ commit }: any) => {
commit(types.LOGOUT_INIT);
new UserProxy().logout().then((response: any) => {
router.push({
name: 'login',
});
// reset the state
commit(types.RESET_STATE);
}).catch((err: any) => {
commit(types.LOGOUT_FAIL, err);
});
};
You could take it easy by tiny package: vuex-extensions
Check out the example on CodeSandbox.
Creating Vuex.Store
import Vuex from 'vuex'
import { createStore } from 'vuex-extensions'
export default createStore(Vuex.Store, {
plugins: []
modules: {}
})
Store resets to initial State
// Vue Component
this.$store.reset()
// Vuex action
modules: {
sub: {
actions: {
logout() {
this.reset()
}
}
}
}
You can do this
index.js
...
const store = new Vuex.Store({
modules: {
...
}
})
store.initialState = clone(store.state)
store.resetState = () => {
store.replaceState(store.initialState)
}
export default store
Other place
this.$store.resetState()
function initialState () {
return { /* .. initial state ... */ }
}
export default {
state: initialState,
mutations: {
reset (state) {
// acquire initial state
const s = initialState()
Object.keys(s).forEach(key => {
state[key] = s[key]
})
}
}
}
This is an official recommendation
issue
if you clear your complete vuex store use:
sessionStorage.clear();

Resetting a vuex module's state to some initialState value

I'm attempting to come up with a method which can reset a modules state back to some initial value, and so far I am coming up o a few conceptual issues.
My base store is the following:
const store = new Vuex.Store({
modules: {
moduleA: moduleA,
},
actions: {
resetAllState: ({ dispatch }) => {"moduleA");
},
resetModuleState: (currentModule) => {
// Perform the reset here...somehow?
}
}
});
The moduleA.js store is created as follows with an intialState:
const initialState = () => ({
helloWorld: {}
});
const moduleA = {
namespaced: true,
state: {
initialState: initialState(),
...initialState(),
}
};
export default moduleA;
So I utilise a spread operator to create the following:
const moduleA = {
namespaced: true,
state: {
initialState: initialState(),
helloWord: {}
}
};
I can then mutate state.helloWorld whilst keeping a copy of the state.initialState...
So, my question now is, within the following global store
resetModuleState: (currentModule) => {
// Perform the reset here...somehow?
}
action, how do I actually perform the reset?
I have treid this as a global way of resetting state:
resetAllState: function() {
let defaultState = {};
Object.keys(store.state).forEach((key) => {
defaultState = {
...defaultState,
[key]: store.state[key].initialState ? store.state[key].initialState : store.state[key],
};
});
store.replaceState(Object.assign({}, defaultState));
},
But to no luck...?
The above code is having issue, the actions can have only access to
{ commit, dispatch, getters } as params
In above code "resetModuleState" takes modueleName in the first parameter, but it will have an object, so directly access the module object by below approach and reset the stathe by just calling initialState() function from each module you have
use this code inside the action "resetAllState"
resetAllState: function({ dispatch }) {
this._modules.root.forEachChild((childModule) => {
childModule.state.initialState();
});
},

Saving only a particular piece of state in localStorage w/ Redux

How to save in localStorage using Redux, only a particular piece of state?
For example, my state in list reducer is defined as follows:
state = {
companies: [],
currentDisplay: '',
recordNotFound: false,
}
This is my combineReducer file:
const rootReducer = combineReducers({
list: listReducer,
form: formReducer
})
localStorage.js:
export const loadState = () => {
try {
const serializedState = localStorage.getItem('state')
if (serializedState === null) {
return undefined;
}
return JSON.parse(serializedState)
} catch (err) {
return undefined
}
}
export const saveState = (state) => {
try {
const serializedState = JSON.stringify(state)
localStorage.setItem('state', serializedState)
} catch (err) {
// to define
}
}
And after browser reloads I want only companies: [{obj1}, {obj2}, ...] array to be preloaded and the rest of state reset to default values f.e. currentDisplay: '' to be equal ''.
Right now responsible for this operation code looks like this:
store.subscribe(() => {
saveState({
list: store.getState().list
})
})
And it stores the whole list obviously...
I guess I could easily reset these parameters in React using setState(), but would like to do this properly.
You can save just the companies parameter on localStorage if you don't need the other parameters to be loaded.
store.subscribe(() => {
saveState({
companies: store.getState().list.companies
})
})

How to reset the state of a Redux store?

I am using Redux for state management.
How do I reset the store to its initial state?
For example, let’s say I have two user accounts (u1 and u2).
Imagine the following sequence of events:
User u1 logs into the app and does something, so we cache some data in the store.
User u1 logs out.
User u2 logs into the app without refreshing the browser.
At this point, the cached data will be associated with u1, and I would like to clean it up.
How can I reset the Redux store to its initial state when the first user logs out?
One way to do that would be to write a root reducer in your application.
The root reducer would normally delegate handling the action to the reducer generated by combineReducers(). However, whenever it receives USER_LOGOUT action, it returns the initial state all over again.
For example, if your root reducer looked like this:
const rootReducer = combineReducers({
/* your app’s top-level reducers */
})
You can rename it to appReducer and write a new rootReducer delegating to it:
const appReducer = combineReducers({
/* your app’s top-level reducers */
})
const rootReducer = (state, action) => {
return appReducer(state, action)
}
Now we just need to teach the new rootReducer to return the initial state in response to the USER_LOGOUT action. As we know, reducers are supposed to return the initial state when they are called with undefined as the first argument, no matter the action. Let’s use this fact to conditionally strip the accumulated state as we pass it to appReducer:
const rootReducer = (state, action) => {
if (action.type === 'USER_LOGOUT') {
return appReducer(undefined, action)
}
return appReducer(state, action)
}
Now, whenever USER_LOGOUT fires, all reducers will be initialized anew. They can also return something different than they did initially if they want to because they can check action.type as well.
To reiterate, the full new code looks like this:
const appReducer = combineReducers({
/* your app’s top-level reducers */
})
const rootReducer = (state, action) => {
if (action.type === 'USER_LOGOUT') {
return appReducer(undefined, action)
}
return appReducer(state, action)
}
In case you are using redux-persist, you may also need to clean your storage. Redux-persist keeps a copy of your state in a storage engine, and the state copy will be loaded from there on refresh.
First, you need to import the appropriate storage engine and then, to parse the state before setting it to undefined and clean each storage state key.
const rootReducer = (state, action) => {
if (action.type === SIGNOUT_REQUEST) {
// for all keys defined in your persistConfig(s)
storage.removeItem('persist:root')
// storage.removeItem('persist:otherKey')
return appReducer(undefined, action);
}
return appReducer(state, action);
};
Dan Abramov's answer is correct except we experienced a strange issue when using the react-router-redux package along with this approach.
Our fix was to not set the state to undefined but rather still use the current routing reducer. So I would suggest implementing the solution below if you are using this package
const rootReducer = (state, action) => {
if (action.type === 'USER_LOGOUT') {
const { routing } = state
state = { routing }
}
return appReducer(state, action)
}
Define an action:
const RESET_ACTION = {
type: "RESET"
}
Then in each of your reducers assuming you are using switch or if-else for handling multiple actions through each reducer. I am going to take the case for a switch.
const INITIAL_STATE = {
loggedIn: true
}
const randomReducer = (state=INITIAL_STATE, action) {
switch(action.type) {
case 'SOME_ACTION_TYPE':
//do something with it
case "RESET":
return INITIAL_STATE; //Always return the initial state
default:
return state;
}
}
This way whenever you call RESET action, you reducer will update the store with default state.
Now, for logout you can handle the like below:
const logoutHandler = () => {
store.dispatch(RESET_ACTION)
// Also the custom logic like for the rest of the logout handler
}
Every time a userlogs in, without a browser refresh. Store will always be at default.
store.dispatch(RESET_ACTION) just elaborates the idea. You will most likely have an action creator for the purpose. A much better way will be that you have a LOGOUT_ACTION.
Once you dispatch this LOGOUT_ACTION. A custom middleware can then intercept this action, either with Redux-Saga or Redux-Thunk. Both ways however, you can dispatch another action 'RESET'. This way store logout and reset will happen synchronously and your store will ready for another user login.
Just a simplified answer to Dan Abramov's answer:
const rootReducer = combineReducers({
auth: authReducer,
...formReducers,
routing
});
export default (state, action) =>
rootReducer(action.type === 'USER_LOGOUT' ? undefined : state, action);
Using Redux Toolkit and/or Typescript:
const appReducer = combineReducers({
/* your app’s top-level reducers */
});
const rootReducer = (
state: ReturnType<typeof appReducer>,
action: AnyAction
) => {
/* if you are using RTK, you can import your action and use it's type property instead of the literal definition of the action */
if (action.type === logout.type) {
return appReducer(undefined, { type: undefined });
}
return appReducer(state, action);
};
From a security perspective, the safest thing to do when logging a user out is to reset all persistent state (e.x. cookies, localStorage, IndexedDB, Web SQL, etc) and do a hard refresh of the page using window.location.reload(). It's possible a sloppy developer accidentally or intentionally stored some sensitive data on window, in the DOM, etc. Blowing away all persistent state and refreshing the browser is the only way to guarantee no information from the previous user is leaked to the next user.
(Of course, as a user on a shared computer you should use "private browsing" mode, close the browser window yourself, use the "clear browsing data" function, etc, but as a developer we can't expect everyone to always be that diligent)
const reducer = (state = initialState, { type, payload }) => {
switch (type) {
case RESET_STORE: {
state = initialState
}
break
}
return state
}
You can also fire an action which is handled by all or some reducers, that you want to reset to initial store. One action can trigger a reset to your whole state, or just a piece of it that seems fit to you. I believe this is the simplest and most controllable way of doing this.
With Redux if have applied the following solution, which assumes I have set an initialState in all my reducers (e.g. { user: { name, email }}). In many components I check on these nested properties, so with this fix, I prevent my renders methods are broken on coupled property conditions (e.g. if state.user.email, which will throw an error user is undefined if the upper mentioned solutions).
const appReducer = combineReducers({
tabs,
user
})
const initialState = appReducer({}, {})
const rootReducer = (state, action) => {
if (action.type === 'LOG_OUT') {
state = initialState
}
return appReducer(state, action)
}
UPDATE NGRX4
If you are migrating to NGRX 4, you may have noticed from the migration guide that the rootreducer method for combining your reducers has been replaced with the ActionReducerMap method. At first, this new way of doing things might make resetting the state a challenge. It is actually straightforward, yet the way of doing this has changed.
This solution is inspired by the meta-reducers API section of the NGRX4 Github docs.
First, lets say your are combining your reducers like this using NGRX's new ActionReducerMap option:
//index.reducer.ts
export const reducers: ActionReducerMap<State> = {
auth: fromAuth.reducer,
layout: fromLayout.reducer,
users: fromUsers.reducer,
networks: fromNetworks.reducer,
routingDisplay: fromRoutingDisplay.reducer,
routing: fromRouting.reducer,
routes: fromRoutes.reducer,
routesFilter: fromRoutesFilter.reducer,
params: fromParams.reducer
}
Now, let's say you want to reset the state from within app.module
//app.module.ts
import { IndexReducer } from './index.reducer';
import { StoreModule, ActionReducer, MetaReducer } from '#ngrx/store';
...
export function debug(reducer: ActionReducer<any>): ActionReducer<any> {
return function(state, action) {
switch (action.type) {
case fromAuth.LOGOUT:
console.log("logout action");
state = undefined;
}
return reducer(state, action);
}
}
export const metaReducers: MetaReducer<any>[] = [debug];
#NgModule({
imports: [
...
StoreModule.forRoot(reducers, { metaReducers}),
...
]
})
export class AppModule { }
And that is basically one way to achieve the same affect with NGRX 4.
My workaround when working with typescript, built on top of Dan Abramov's answer (redux typings make it impossible to pass undefined to reducer as the first argument, so I cache initial root state in a constant):
// store
export const store: Store<IStoreState> = createStore(
rootReducer,
storeEnhacer,
)
export const initialRootState = {
...store.getState(),
}
// root reducer
const appReducer = combineReducers<IStoreState>(reducers)
export const rootReducer = (state: IStoreState, action: IAction<any>) => {
if (action.type === "USER_LOGOUT") {
return appReducer(initialRootState, action)
}
return appReducer(state, action)
}
// auth service
class Auth {
...
logout() {
store.dispatch({type: "USER_LOGOUT"})
}
}
Simply have your logout link clear session and refresh the page. No additional code needed for your store. Any time you want to completely reset the state a page refresh is a simple and easily repeatable way to handle it.
If you are using redux-actions, here's a quick workaround using a HOF(Higher Order Function) for handleActions.
import { handleActions } from 'redux-actions';
export function handleActionsEx(reducer, initialState) {
const enhancedReducer = {
...reducer,
RESET: () => initialState
};
return handleActions(enhancedReducer, initialState);
}
And then use handleActionsEx instead of original handleActions to handle reducers.
Dan's answer gives a great idea about this problem, but it didn't work out well for me, because I'm using redux-persist.
When used with redux-persist, simply passing undefined state didn't trigger persisting behavior, so I knew I had to manually remove item from storage (React Native in my case, thus AsyncStorage).
await AsyncStorage.removeItem('persist:root');
or
await persistor.flush(); // or await persistor.purge();
didn't work for me either - they just yelled at me. (e.g., complaining like "Unexpected key _persist ...")
Then I suddenly pondered all I want is just make every individual reducer return their own initial state when RESET action type is encountered. That way, persisting is handled naturally. Obviously without above utility function (handleActionsEx), my code won't look DRY (although it's just a one liner, i.e. RESET: () => initialState), but I couldn't stand it 'cuz I love metaprogramming.
Combining Dan Abramov's answer, Ryan Irilli's answer and Rob Moorman's answer, to account for keeping the router state and initializing everything else in the state tree, I ended up with this:
const rootReducer = (state, action) => appReducer(action.type === LOGOUT ? {
...appReducer({}, {}),
router: state && state.router || {}
} : state, action);
I have created actions to clear state. So when I dispatch a logout action creator I dispatch actions to clear state as well.
User record action
export const clearUserRecord = () => ({
type: CLEAR_USER_RECORD
});
Logout action creator
export const logoutUser = () => {
return dispatch => {
dispatch(requestLogout())
dispatch(receiveLogout())
localStorage.removeItem('auth_token')
dispatch({ type: 'CLEAR_USER_RECORD' })
}
};
Reducer
const userRecords = (state = {isFetching: false,
userRecord: [], message: ''}, action) => {
switch (action.type) {
case REQUEST_USER_RECORD:
return { ...state,
isFetching: true}
case RECEIVE_USER_RECORD:
return { ...state,
isFetching: false,
userRecord: action.user_record}
case USER_RECORD_ERROR:
return { ...state,
isFetching: false,
message: action.message}
case CLEAR_USER_RECORD:
return {...state,
isFetching: false,
message: '',
userRecord: []}
default:
return state
}
};
I am not sure if this is optimal?
My take to keep Redux from referencing to the same variable of the initial state:
// write the default state as a function
const defaultOptionsState = () => ({
option1: '',
option2: 42,
});
const initialState = {
options: defaultOptionsState() // invoke it in your initial state
};
export default (state = initialState, action) => {
switch (action.type) {
case RESET_OPTIONS:
return {
...state,
options: defaultOptionsState() // invoke the default function to reset this part of the state
};
default:
return state;
}
};
I've created a component to give Redux the ability to reset state, you just need to use this component to enhance your store and dispatch a specific action.type to trigger reset. The thought of implementation is the same as what Dan Abramov said in their answer.
Github: https://github.com/wwayne/redux-reset
The following solution worked for me.
I added resetting state function to meta reducers.The key was to use
return reducer(undefined, action);
to set all reducers to initial state. Returning undefined instead was causing errors due to the fact that the structure of the store has been destroyed.
/reducers/index.ts
export function resetState(reducer: ActionReducer<State>): ActionReducer<State> {
return function (state: State, action: Action): State {
switch (action.type) {
case AuthActionTypes.Logout: {
return reducer(undefined, action);
}
default: {
return reducer(state, action);
}
}
};
}
export const metaReducers: MetaReducer<State>[] = [ resetState ];
app.module.ts
import { StoreModule } from '#ngrx/store';
import { metaReducers, reducers } from './reducers';
#NgModule({
imports: [
StoreModule.forRoot(reducers, { metaReducers })
]
})
export class AppModule {}
Dan Abramov's answer helped me solve my case. However, I encountered a case where not the entire state had to be cleared. So I did it this way:
const combinedReducer = combineReducers({
// my reducers
});
const rootReducer = (state, action) => {
if (action.type === RESET_REDUX_STATE) {
// clear everything but keep the stuff we want to be preserved ..
delete state.something;
delete state.anotherThing;
}
return combinedReducer(state, action);
}
export default rootReducer;
Just an extension to #dan-abramov answer, sometimes we may need to retain certain keys from being reset.
const retainKeys = ['appConfig'];
const rootReducer = (state, action) => {
if (action.type === 'LOGOUT_USER_SUCCESS' && state) {
state = !isEmpty(retainKeys) ? pick(state, retainKeys) : undefined;
}
return appReducer(state, action);
};
This approach is very right: Destruct any specific state "NAME" to ignore and keep others.
const rootReducer = (state, action) => {
if (action.type === 'USER_LOGOUT') {
state.NAME = undefined
}
return appReducer(state, action)
}
For me to reset the state to its initial state, I wrote the following code:
const appReducers = (state, action) =>
combineReducers({ reducer1, reducer2, user })(
action.type === "LOGOUT" ? undefined : state,
action
);
I found that Dan Abramov's answer worked well for me, but it triggered the ESLint no-param-reassign error - https://eslint.org/docs/rules/no-param-reassign
Here's how I handled it instead, making sure to create a copy of the state (which is, in my understanding, the Reduxy thing to do...):
import { combineReducers } from "redux"
import { routerReducer } from "react-router-redux"
import ws from "reducers/ws"
import session from "reducers/session"
import app from "reducers/app"
const appReducer = combineReducers({
"routing": routerReducer,
ws,
session,
app
})
export default (state, action) => {
const stateCopy = action.type === "LOGOUT" ? undefined : { ...state }
return appReducer(stateCopy, action)
}
But maybe creating a copy of the state to just pass it into another reducer function that creates a copy of that is a little over-complicated? This doesn't read as nicely, but is more to-the-point:
export default (state, action) => {
return appReducer(action.type === "LOGOUT" ? undefined : state, action)
}
First on initiation of our application the reducer state is fresh and new with default InitialState.
We have to add an action that calls on APP inital load to persists default state.
While logging out of the application we can simple reAssign the default state and reducer will work just as new.
Main APP Container
componentDidMount() {
this.props.persistReducerState();
}
Main APP Reducer
const appReducer = combineReducers({
user: userStatusReducer,
analysis: analysisReducer,
incentives: incentivesReducer
});
let defaultState = null;
export default (state, action) => {
switch (action.type) {
case appActions.ON_APP_LOAD:
defaultState = defaultState || state;
break;
case userLoginActions.USER_LOGOUT:
state = defaultState;
return state;
default:
break;
}
return appReducer(state, action);
};
On Logout calling action for resetting state
function* logoutUser(action) {
try {
const response = yield call(UserLoginService.logout);
yield put(LoginActions.logoutSuccess());
} catch (error) {
toast.error(error.message, {
position: toast.POSITION.TOP_RIGHT
});
}
}
One thing Dan Abramov's answer doesn't do is clear the cache for parameterized selectors. If you have a selector like this:
export const selectCounter1 = (state: State) => state.counter1;
export const selectCounter2 = (state: State) => state.counter2;
export const selectTotal = createSelector(
selectCounter1,
selectCounter2,
(counter1, counter2) => counter1 + counter2
);
Then you would have to release them on logout like this:
selectTotal.release();
Otherwise, the memoized value for the last call of the selector and the values of the last parameters will still be in memory.
Code samples are from the ngrx docs.
A quick and easy option that worked for me was using redux-reset . Which was straightforward and also has some advanced options, for larger apps.
Setup in create store
import reduxReset from 'redux-reset'
// ...
const enHanceCreateStore = compose(
applyMiddleware(...),
reduxReset() // Will use 'RESET' as default action.type to trigger reset
)(createStore)
const store = enHanceCreateStore(reducers)
Dispatch your 'reset' in your logout function
store.dispatch({
type: 'RESET'
})
Approach with Redux Toolkit:
export const createRootReducer = (history: History) => {
const rootReducerFn = combineReducers({
auth: authReducer,
users: usersReducer,
...allOtherReducers,
router: connectRouter(history),
});
return (state: Parameters<typeof rootReducerFn>[0], action: Parameters<typeof rootReducerFn>[1]) =>
rootReducerFn(action.type === appActions.reset.type ? undefined : state, action);
};
why don't you just use return module.exports.default() ;)
export default (state = {pending: false, error: null}, action = {}) => {
switch (action.type) {
case "RESET_POST":
return module.exports.default();
case "SEND_POST_PENDING":
return {...state, pending: true, error: null};
// ....
}
return state;
}
Note: make sure you set action default value to {} and you are ok because you don't want to encounter error when you check action.type inside the switch statement.
Another option is to:
store.dispatch({type: '##redux/INIT'})
'##redux/INIT' is the action type that redux dispatches automatically when you createStore, so assuming your reducers all have a default already, this would get caught by those and start your state off fresh. It might be considered a private implementation detail of redux, though, so buyer beware...
for me what worked the best is to set the initialState instead of state:
const reducer = createReducer(initialState,
on(proofActions.cleanAdditionalInsuredState, (state, action) => ({
...initialState
})),
If you want to reset a single reducer
For example
const initialState = {
isLogged: false
}
//this will be your action
export const resetReducer = () => {
return {
type: "RESET"
}
}
export default (state = initialState, {
type,
payload
}) => {
switch (type) {
//your actions will come her
case "RESET":
return {
...initialState
}
}
}
//and from your frontend
dispatch(resetReducer())

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