How to implement rtk's createApi query for debouncing - reactjs

Can someone help me in implementing the debounce functionality using creatApi with query implementation from redux toolkit.
Thanks in advance.

I personally didn't find any debounce implementation in RTK Query out-of-the-box. But you can implement it yourself.
Define an api. I'm using an openlibrary's one:
import { createApi, fetchBaseQuery } from '#reduxjs/toolkit/query/react';
type BooksSearchResult = {
docs: Book[];
};
type Book = {
key: string;
title: string;
author_name: string;
first_publish_year: number;
};
export const booksApi = createApi({
reducerPath: 'booksApi',
baseQuery: fetchBaseQuery({ baseUrl: 'http://openlibrary.org/' }),
endpoints: builder => ({
searchBooks: builder.query<BooksSearchResult, string>({
query: term => `search.json?q=${encodeURIComponent(term)}`,
}),
}),
});
export const { useSearchBooksQuery } = booksApi;
Next thing you need is debounce hook, which guarantees that some value changes only after specified delay:
function useDebounce(value: string, delay: number): string {
const [debouncedValue, setDebouncedValue] = useState(value);
useEffect(() => {
const handler = setTimeout(() => {
setDebouncedValue(value);
}, delay);
return () => {
clearTimeout(handler);
};
}, [value, delay]);
return debouncedValue;
}
Use debounce hook on your search form:
import React, { useEffect, useState } from "react";
import BookSearchResults from "./BookSearchResults";
function useDebounce(value: string, delay: number): string {
const [debouncedValue, setDebouncedValue] = useState(value);
useEffect(() => {
const handler = setTimeout(() => {
setDebouncedValue(value);
}, delay);
return () => {
clearTimeout(handler);
};
}, [value, delay]);
return debouncedValue;
}
const DebounceExample: React.FC = () => {
const [searchTerm, setSearchTerm] = useState("");
const debouncedSearchTerm = useDebounce(searchTerm, 500);
return (
<React.Fragment>
<h1>Debounce example</h1>
<p>Start typing some book name. Search starts at length 5</p>
<input
className="search-input"
type="text"
placeholder="Search books"
value={searchTerm}
onChange={(e) => setSearchTerm(e.target.value)}
/>
<BookSearchResults searchTerm={debouncedSearchTerm}></BookSearchResults>
</React.Fragment>
);
};
export default DebounceExample;
Use the search query hook in search results component. It uses its own state for search term value, which is very convenient if you want to add extra "filters" for debounced value (for example, start query only when search term's length is greater than some value).
import React, { useState, useEffect } from "react";
import { useSearchBooksQuery } from "./booksApi";
type BookSearchResultsProps = {
searchTerm: string;
};
const BookSearchResults: React.FC<BookSearchResultsProps> = ({
searchTerm
}: BookSearchResultsProps) => {
const [filteredSearchTerm, setFilteredSearchTerm] = useState(searchTerm);
const { data, error, isLoading, isFetching } = useSearchBooksQuery(
filteredSearchTerm
);
const books = data?.docs ?? [];
useEffect(() => {
if (searchTerm.length === 0 || searchTerm.length > 4) {
setFilteredSearchTerm(searchTerm);
}
}, [searchTerm]);
if (error) {
return <div className="text-hint">Error while fetching books</div>;
}
if (isLoading) {
return <div className="text-hint">Loading books...</div>;
}
if (isFetching) {
return <div className="text-hint">Fetching books...</div>;
}
if (books.length === 0) {
return <div className="text-hint">No books found</div>;
}
return (
<ul>
{books.map(({ key, title, author_name, first_publish_year }) => (
<li key={key}>
{author_name}: {title}, {first_publish_year}
</li>
))}
</ul>
);
};
export default BookSearchResults;
Full example is available here.

In my case the following solution worked well.
I used component way of debouncing. Use any debounce fn, in my way:
npm i debounce
And then in component
import debounce from 'debounce';
const Component = () => {
const { data, refetch } = useYourQuery();
const [mutate] = useYourMutation();
const handleDebouncedRequest = debouce(async () => {
try {
// you can use refetch or laze query way
await refetch();
await mutate();
} catch {}
}, 2000);
// ...other component logic
}

after the first render our request hook will try to send the request we can bypass this with the skipToken
the request will not be sent until searchTerm returns some value
import { useDebounce } from 'use-debounce'
import { skipToken } from '#reduxjs/toolkit/query'
const [storeName, setStoreName] = useState('')
const [searchTerm] = useDebounce(storeName, 1500)
const { data } = useSearchStoresRequestQuery(searchTerm || skipToken)
more about skipToken: https://redux-toolkit.js.org/rtk-query/usage/conditional-fetching
and also inside my useSearchStoresRequestQuery
endpoints: (builder) => ({
getStoresWithSearchRequest: builder.query({
query: ({searchTerm}) => {
return {
url: `admin/v1/stores?searchTerm?${searchTerm}`,
method: 'GET',
}
},

Related

React Query invalidateQueries not updating the UI

My UI is not updating on the creation of a project with invalidateQueries. I have confirmed that the database updates are being made successfully and the onSuccess functions are being called. I'm unsure what I am doing wrong, and would love some help.
useProjects.ts
import { getProjects } from 'queries/get-projects';
import { useQuery } from 'react-query';
function useGetProjectsQuery() {
return useQuery('projects', async () => {
return getProjects().then((result) => result.data);
});
}
export default useGetProjectsQuery;
get-project.ts
import { supabase } from '../utils/supabase-client';
export const getProjects = async () => {
return supabase.from('projects').select(`*`);
};
useCreateProject.ts
import { useUser } from '#/utils/useUser';
import { createProject } from 'queries/create-project';
import { useMutation, useQueryClient } from 'react-query';
export const useCreateProject = () => {
const { user } = useUser();
const queryClient = useQueryClient();
return useMutation(
({ title, type, bgColorClass, pinned }: any) => {
return createProject(title, type, bgColorClass, pinned, user.id).then(
(result) => result.data
);
},
{
onSuccess: () => {
queryClient.invalidateQueries('projects');
}
}
);
};
create-project.ts
import { supabase } from '../utils/supabase-client';
export async function createProject(
title: string,
type: string,
bgColorClass: string,
pinned: boolean,
userId: string
) {
return supabase
.from('projects')
.insert([
{ title, type, bg_color_class: bgColorClass, pinned, user_id: userId }
]);
}
Home Component
const { data: projects, isLoading, isError } = useGetProjectsQuery();
const createProject = useCreateProject();
const createNewProject = async () => {
await createProject.mutateAsync({
title: projectName,
type: selectedType.name,
bgColorClass: _.sample(projectColors),
pinned: false
});
};
_app.tsx
export default function MyApp({ Component, pageProps }: AppProps) {
const [initialContext, setInitialContext] = useState();
const [supabaseClient] = useState(() =>
createBrowserSupabaseClient<Database>()
);
useEffect(() => {
document.body.classList?.remove('loading');
}, []);
const getUserDetails = async () =>
supabaseClient.from('users').select('*').single();
const getSubscription = async () =>
supabaseClient
.from('subscriptions')
.select('*, prices(*, products(*))')
.in('status', ['trialing', 'active'])
.single();
const getInitialData = async () => {
const userDetails = await getUserDetails();
const subscription = await getSubscription();
setInitialContext({
//#ts-ignore
userDetails: userDetails.data,
subscription: subscription.data
});
};
const queryClient = new QueryClient({
defaultOptions: {
queries: {
retry: 0
}
}
});
useEffect(() => {
getInitialData();
}, []);
return (
<QueryClientProvider client={queryClient}>
<SessionContextProvider supabaseClient={supabaseClient}>
<MyUserContextProvider initial={initialContext}>
<SidebarProvider>
<Component {...pageProps} />
<ReactQueryDevtools initialIsOpen={false} />
</SidebarProvider>
</MyUserContextProvider>
</SessionContextProvider>
</QueryClientProvider>
);
}
I have tried moving the onSuccess followup calls to the Home component, and within the hooks, neither one updates the UI. I'm unsure what I am doing wrong and the react query devtools is not helpful.
You are instantiating QueryClient on every render pass so the cache of query keys is being torn down and rebuilt often.
Instantiate this outside of render:
const queryClient = new QueryClient({
defaultOptions: {
queries: {
retry: 0
}
}
});
export default function MyApp({ Component, pageProps }: AppProps) {
const [initialContext, setInitialContext] = useState();
// ... etc
This will ensure the client is always stable.

Rerendering page based on submission in React/Redux with Calling API

I am trying to call API with Redux, and it calls again based on a form submission.
which means if query is none, it returns all lists or it returns lists that match the query.
// List.tsx
import React, { useEffect, useState } from "react";
import { connect } from "react-redux";
import { getFeatures, increasePage } from "../../redux/featuresSlice";
import { FeatureItem } from "../../components/featureItem";
interface IFeatureProp {
featureObject: any;
getFeaturesWith: any;
}
const FeatureList = ({
featureObject,
getFeaturesWith,
}: // page,
IFeatureProp) => {
const [keywords, setKeywords] = useState("");
const fetchData = async () => {
getFeaturesWith(featureObject.page, keywords);
};
const handleSubmit = (e: any) => {
e.preventDefault();
fetchData();
};
useEffect(() => {
console.log(keywords);
fetchData();
}, []);
return (
<div className="max-w-screen-xl mx-auto mt-8">
<div className="px-12">
<div className="relative">
<div className="relative">
<form onSubmit={handleSubmit}>
<div className="absolute top-0 bottom-0 left-0 flex items-center px-5">
</div>
<input
type="text"
placeholder="Search..."
value={keywords}
onChange={e => setKeywords(e.target.value)}
/>
</form>
</div>
<ul>
{featureObject.features
.map((c: any) => {
return (
<FeatureItem
id={c.id}
name={c.name}
desc={c.desc}
/>
);
})}
</ul>
</div>
</div>
</div>
);
};
function mapStateToProps(state: any) {
return { featureObject: state.featuresReducer.explore };
}
function mapDispatchToProps(dispatch: any) {
return {
getFeaturesWith: (page: any, keyword: string) =>
dispatch(getFeatures(page, keyword)),
increasePageWith: () => dispatch(increasePage(1)),
};
}
export default connect(mapStateToProps, mapDispatchToProps)(FeatureList);
//featuresSlice.js
import { createSlice } from "#reduxjs/toolkit";
import api from "../api";
const featuresSlice = createSlice({
name: "features",
initialState: {
explore: {
page: 1,
features: [],
},
favs: [],
},
reducers: {
setExploreFeatures(state, action) {
const { explore } = state;
const { payload } = action;
payload.features.forEach(payloadFeature => {
const exists = explore.features.find(
savedFeature => savedFeature.id === payloadFeature.id
);
if (!exists) {
explore.features.push(payloadFeature);
}
});
state.explore.page = payload.page;
},
},
});
export const { setExploreFeatures, increasePage, setFavs, setFav } =
featuresSlice.actions;
export const getFeatures = (page, keyword) => async (dispatch, getState) => {
const {
usersReducer: { token },
} = getState();
try {
const {
data: { results },
} = await api.features(token, page, keyword);
dispatch(
setExploreFeatures({
features: results,
page: 1,
})
);
} catch (e) {
console.warn(e);
}
};
export default featuresSlice.reducer;
when I submit keyword, it works as I expected at backend.
[07/Feb/2022 01:55:23] "GET /api/v1/features/?search=abcd HTTP/1.1" 200 3615
And I see only lists that match the query in redux-debugger.
But it doesn't re-render the page, which means I only see whole lists.
Is there what I can do for updating state?
The issue is that your reducer is mutating the state, which should never be the case within the Redux ideology.
Instead, you should be creating a new state object (with your changes applied) and return it from the reducer. And if you don't want to modify the state - just return the original one kept intact. All your reducers should be like that.
reducers: {
setExploreFeatures(state, action) {
const { payload } = action;
const newFeatures = payload.features.filter(x => !state.explore.features.some(y => y.id === x.id));
return { ...state, explore: { ...state.explore, features: [...state.explore.features, ...newFeatures], page: payload.page } };
},
},
along these lines ^^

Need to call an alert message component from action in react

I've created a common component and exported it, i need to call that component in action based on the result from API. If the api success that alert message component will call with a message as "updated successfully". error then show with an error message.
calling service method in action. is there any way we can do like this? is it possible to call a component in action
You have many options.
1. Redux
If you are a fan of Redux, or your project already use Redux, you might want to do it like this.
First declare the slice, provider and hook
const CommonAlertSlice = createSlice({
name: 'CommonAlert',
initialState : {
error: undefined
},
reducers: {
setError(state, action: PayloadAction<string>) {
state.error = action.payload;
},
clearError(state) {
state.error = undefined;
},
}
});
export const CommonAlertProvider: React.FC = ({children}) => {
const error = useSelector(state => state['CommonAlert'].error);
const dispatch = useDispatch();
return <>
<MyAlert
visible={error !== undefined}
body={error} onDismiss={() =>
dispatch(CommonAlertSlice.actions.clearError())} />
{children}
</>
}
export const useCommonAlert = () => {
const dispatch = useDispatch();
return {
setError: (error: string) => dispatch(CommonAlertSlice.actions.setError(error)),
}
}
And then use it like this.
const App: React.FC = () => {
return <CommonAlertProvider>
<YourComponent />
</CommonAlertProvider>
}
const YourComponent: React.FC = () => {
const { setError } = useCommonAlert();
useEffect(() => {
callYourApi()
.then(...)
.catch(err => {
setError(err.message);
});
});
return <> ... </>
}
2. React Context
If you like the built-in React Context, you can make it more simpler like this.
const CommonAlertContext = createContext({
setError: (error: string) => {}
});
export const CommonAlertProvider: React.FC = ({children}) => {
const [error, setError] = useState<string>();
return <CommonAlertContext.Provider value={{
setError
}}>
<MyAlert
visible={error !== undefined}
body={error} onDismiss={() => setError(undefined)} />
{children}
</CommonAlertContext.Provider>
}
export const useCommonAlert = () => useContext(CommonAlertContext);
And then use it the exact same way as in the Redux example.
3. A Hook Providing a Render Method
This option is the simplest.
export const useAlert = () => {
const [error, setError] = useState<string>();
return {
setError,
renderAlert: () => {
return <MyAlert
visible={error !== undefined}
body={error} onDismiss={() => setError(undefined)} />
}
}
}
Use it.
const YourComponent: React.FC = () => {
const { setError, renderAlert } = useAlert();
useEffect(() => {
callYourApi()
.then(...)
.catch(err => {
setError(err.message);
});
});
return <>
{renderAlert()}
...
</>
}
I saw the similar solution in Antd library, it was implemented like that
codesandbox link
App.js
import "./styles.css";
import alert from "./alert";
export default function App() {
const handleClick = () => {
alert();
};
return (
<div className="App">
<button onClick={handleClick}>Show alert</button>
</div>
);
}
alert function
import ReactDOM from "react-dom";
import { rootElement } from ".";
import Modal from "./Modal";
export default function alert() {
const modalEl = document.createElement("div");
rootElement.appendChild(modalEl);
function destroy() {
rootElement.removeChild(modalEl);
}
function render() {
ReactDOM.render(<Modal destroy={destroy} />, modalEl);
}
render();
}
Your modal component
import { useEffect } from "react";
export default function Modal({ destroy }) {
useEffect(() => {
return () => {
destroy();
};
}, [destroy]);
return (
<div>
Your alert <button onClick={destroy}>Close</button>
</div>
);
}
You can't call a Component in action, but you can use state for call a Component in render, using conditional rendering or state of Alert Component such as isShow.

React useState hook is not working as expected inside useEffect hook

Disclaimer: Please don't mark this as duplicate. I've seen similar questions with answers. But none of them is working for me. I'm just learning React.
What I'm trying to achieve is basically infinite scrolling. So that when a user scrolls to the end of the page, more data will load.
I've used scroll eventListener to achieve this. And it is working.
But I'm facing problems with the state of the variables.
First, I've changed the loading state to true. Then fetch data and set the state to false.
Second, when scrolling to the end of the page occurs, I again change the loading state to true. Add 1 with pageNo. Then again fetch data and set the loading state to false.
The problems are:
loading state somehow remains true.
Changing the pageNo state is not working. pageNo always remains to 1.
And actually none of the states are working as expected.
My goal: (Sequential)
Set loading to true.
Fetch 10 posts from API after component initialization.
Set loading to false.
After the user scrolls end of the page, add 1 with pageNo.
Repeat Step 1 to Step 3 until all posts loaded.
After getting an empty response from API set allPostsLoaded to true.
What I've tried:
I've tried adding all the states into dependencyList array of useEffect hook. But then an infinite loop occurs.
I've also tried adding only pageNo and loading state to the array, but same infinite loop occurs.
Source:
import React, { lazy, useState } from 'react';
import { PostSection } from './Home.styles';
import { BlogPost } from '../../models/BlogPost';
import { PostService } from '../../services/PostService';
const defaultPosts: BlogPost[] = [{
Id: 'asdfg',
Content: 'Hi, this is demo content',
Title: 'Demo title',
sections: [],
subTitle: '',
ReadTime: 1,
CreatedDate: new Date()
}];
const defaultPageNo = 1;
const PostCardComponent = lazy(() => import('./../PostCard/PostCard'));
const postService = new PostService();
const Home = (props: any) => {
const [posts, setPosts]: [BlogPost[], (posts: BlogPost[]) => void] = useState(defaultPosts);
const [pageNo, setPageNo] = useState(defaultPageNo);
const [pageSize, setPageSize] = useState(10);
const [loading, setLoading] = useState(false);
const [allPostsLoaded, setAllPostsLoaded] = useState(false);
const [featuredPost, setFeaturedPost]: [BlogPost, (featuredPost: BlogPost) => void] = useState(defaultPosts[0]);
async function getPosts() {
return await postService.getPosts(pageSize, pageNo);
}
async function getFeaturedPost() {
return await postService.getFeaturedPost();
}
function handleScroll(event: any) {
console.log('loading ' + loading);
console.log('allPostsLoaded ' + allPostsLoaded);
var target = event.target.scrollingElement;
if (!loading && !allPostsLoaded && target.scrollTop + target.clientHeight === target.scrollHeight) {
setLoading(true);
setPageNo(pageNo => pageNo + 1);
setTimeout(()=>{
getPosts()
.then(response => {
const newPosts = response.data.data;
setLoading(false);
if (newPosts.length) {
const temp = [ ...posts ];
newPosts.forEach(post => !temp.map(m => m.Id).includes(post.Id) ? temp.push(post) : null);
setPosts(temp);
} else {
setAllPostsLoaded(true);
}
})
}, 1000);
}
}
function init() {
setLoading(true);
Promise.all([getFeaturedPost(), getPosts()])
.then(
responses => {
setLoading(false);
setFeaturedPost(responses[0].data.data);
setPosts(responses[1].data.data);
}
);
}
React.useEffect(() => {
window.addEventListener("scroll", handleScroll);
init();
return () => {
window.removeEventListener("scroll", handleScroll);
};
}, []
);
return (
<PostSection className="px-3 py-5 p-md-5">
<div className="container">
<div className="item mb-5">
{posts.map(post => (
<PostCardComponent
key={post.Id}
Title={post.Title}
intro={post.Content}
Id={post.Id}
ReadTime={post.ReadTime}
CreatedDate={post.CreatedDate}
/>
))}
</div>
</div>
</PostSection>
);
};
export default Home;
Used more effects to handle the change of pageNo, loader and allPostsLoaded state worked for me.
Updated Source:
import React, { lazy, useState } from 'react';
import { Guid } from "guid-typescript";
import { PostSection } from './Home.styles';
import { BlogPost } from '../../models/BlogPost';
import { PostService } from '../../services/PostService';
import { Skeleton } from 'antd';
const defaultPosts: BlogPost[] = [{
Id: '456858568568568',
Content: 'Hi, this is demo content. There could have been much more content.',
Title: 'This is a demo title',
sections: [],
subTitle: '',
ReadTime: 1,
CreatedDate: new Date()
}];
const defaultPageNo = 1;
const defaultPageSize = 10;
const PostCardComponent = lazy(() => import('./../PostCard/PostCard'));
const postService = new PostService();
const Home: React.FC<any> = props => {
const [posts, setPosts]: [BlogPost[], (posts: BlogPost[]) => void] = useState(defaultPosts);
const [pageNo, setPageNo] = useState(defaultPageNo);
const [pageSize, setPageSize] = useState(defaultPageSize);
const [loading, setLoading] = useState(false);
const [allPostsLoaded, setAllPostsLoaded] = useState(false);
const [featuredPost, setFeaturedPost]: [BlogPost, (featuredPost: BlogPost) => void] = useState(defaultPosts[0]);
function getNewGuid() {
return Guid.create().toString();
}
async function getPosts() {
return await postService.getPosts(pageSize, pageNo);
}
async function getFeaturedPost() {
return await postService.getFeaturedPost();
}
function init() {
setLoading(true);
Promise.all([getFeaturedPost(), getPosts()])
.then(
responses => {
setLoading(false);
setFeaturedPost(responses[0].data.data);
setPosts(responses[1].data.data);
}
);
}
React.useEffect(() => {
init();
return;
}, []);
React.useEffect(() => {
if (allPostsLoaded || loading) return;
function handleScroll(event: any) {
var target = event.target.scrollingElement;
if (!loading && !allPostsLoaded && target.scrollTop + target.clientHeight === target.scrollHeight) {
setPageNo(pageNo => pageNo+1);
}
}
window.addEventListener("scroll", handleScroll);
return () => {
window.removeEventListener("scroll", handleScroll);
};
}, [loading, allPostsLoaded]
);
React.useEffect(() => {
if (pageNo > 1) {
setLoading(true);
setTimeout(()=>{
getPosts()
.then(response => {
const newPosts = response.data.data;
setTimeout(()=>{
setLoading(false);
if (newPosts.length) {
const temp = [ ...posts ];
newPosts.forEach(post => !temp.map(m => m.Id).includes(post.Id) ? temp.push(post) : null);
setPosts(temp);
} else {
setAllPostsLoaded(true);
}
}, 1000);
})
}, 1000);
}
}, [pageNo]
);
return (
<PostSection className="px-3 py-5 p-md-5">
<div className="container">
<div className="item mb-5">
{posts.map(post => (
<PostCardComponent
key={post.Id}
Title={post.Title}
intro={post.Content}
Id={post.Id}
ReadTime={post.ReadTime}
CreatedDate={post.CreatedDate}
/>
))}
</div>
</div>
</PostSection>
);
};
export default Home;

To fix, cancel all subscriptions and asynchronous tasks in a useEffect cleanup function

I have this code
import ReactDOM from "react-dom";
import React, { useState, useEffect } from "react";
import { BrowserRouter as Router, Route, Link } from "react-router-dom";
function ParamsExample() {
return (
<Router>
<div>
<h2>Accounts</h2>
<Link to="/">Netflix</Link>
<Route path="/" component={Miliko} />
</div>
</Router>
);
}
const Miliko = ({ match }) => {
const [data, setData] = useState([]);
const [isLoading, setIsLoading] = useState(false);
const [isError, setIsError] = useState(false);
useEffect(() => {
(async function() {
setIsError(false);
setIsLoading(true);
try {
const Res = await fetch("https://foo0022.firebaseio.com/New.json");
const ResObj = await Res.json();
const ResArr = await Object.values(ResObj).flat();
setData(ResArr);
} catch (error) {
setIsError(true);
}
setIsLoading(false);
})();
console.log(data);
}, [match]);
return <div>{`${isLoading}${isError}`}</div>;
};
function App() {
return (
<div className="App">
<ParamsExample />
</div>
);
}
const rootElement = document.getElementById("root");
ReactDOM.render(<App />, rootElement);
I created three links that open the Miliko component. but when I quickly click on the links I get this error:
To fix, cancel all subscriptions and asynchronous tasks in a useEffect
cleanup function.
I think the problem is caused by dismount before async call finished.
const useAsync = () => {
const [data, setData] = useState(null)
const mountedRef = useRef(true)
const execute = useCallback(() => {
setLoading(true)
return asyncFunc()
.then(res => {
if (!mountedRef.current) return null
setData(res)
return res
})
}, [])
useEffect(() => {
return () => {
mountedRef.current = false
}
}, [])
}
mountedRef is used here to indicate if the component is still mounted. And if so, continue the async call to update component state, otherwise, skip them.
This should be the main reason to not end up with a memory leak (access cleanedup memory) issue.
Demo
https://codepen.io/windmaomao/pen/jOLaOxO , fetch with useAsync
https://codepen.io/windmaomao/pen/GRvOgoa , manual fetch with useAsync
Update
The above answer leads to the following component that we use inside our team.
/**
* A hook to fetch async data.
* #class useAsync
* #borrows useAsyncObject
* #param {object} _ props
* #param {async} _.asyncFunc Promise like async function
* #param {bool} _.immediate=false Invoke the function immediately
* #param {object} _.funcParams Function initial parameters
* #param {object} _.initialData Initial data
* #returns {useAsyncObject} Async object
* #example
* const { execute, loading, data, error } = useAync({
* asyncFunc: async () => { return 'data' },
* immediate: false,
* funcParams: { data: '1' },
* initialData: 'Hello'
* })
*/
const useAsync = (props = initialProps) => {
const {
asyncFunc, immediate, funcParams, initialData
} = {
...initialProps,
...props
}
const [loading, setLoading] = useState(immediate)
const [data, setData] = useState(initialData)
const [error, setError] = useState(null)
const mountedRef = useRef(true)
const execute = useCallback(params => {
setLoading(true)
return asyncFunc({ ...funcParams, ...params })
.then(res => {
if (!mountedRef.current) return null
setData(res)
setError(null)
setLoading(false)
return res
})
.catch(err => {
if (!mountedRef.current) return null
setError(err)
setLoading(false)
throw err
})
}, [asyncFunc, funcParams])
useEffect(() => {
if (immediate) {
execute(funcParams)
}
return () => {
mountedRef.current = false
}
// eslint-disable-next-line react-hooks/exhaustive-deps
}, [])
return {
execute,
loading,
data,
error
}
}
Update 2022
This approach has been adopted in the book https://www.amazon.com/Designing-React-Hooks-Right-Way/dp/1803235950 where this topic has been mentioned in useRef and custom hooks chapters, and more examples are provided there.
useEffect will try to keep communications with your data-fetching procedure even while the component has unmounted. Since this is an anti-pattern and exposes your application to memory leakage, cancelling the subscription to useEffect optimizes your app.
In the simple implementation example below, you'd use a flag (isSubscribed) to determine when to cancel your subscription. At the end of the effect, you'd make a call to clean up.
export const useUserData = () => {
const initialState = {
user: {},
error: null
}
const [state, setState] = useState(initialState);
useEffect(() => {
// clean up controller
let isSubscribed = true;
// Try to communicate with sever API
fetch(SERVER_URI)
.then(response => response.json())
.then(data => isSubscribed ? setState(prevState => ({
...prevState, user: data
})) : null)
.catch(error => {
if (isSubscribed) {
setState(prevState => ({
...prevState,
error
}));
}
})
// cancel subscription to useEffect
return () => (isSubscribed = false)
}, []);
return state
}
You can read up more from this blog juliangaramendy
Without #windmaomao answer, I could spend other hours trying to figure out how to cancel the subscription.
In short, I used two hooks respectively useCallback to memoize function and useEffect to fetch data.
const fetchSpecificItem = useCallback(async ({ itemId }) => {
try {
... fetch data
/*
Before you setState ensure the component is mounted
otherwise, return null and don't allow to unmounted component.
*/
if (!mountedRef.current) return null;
/*
if the component is mounted feel free to setState
*/
} catch (error) {
... handle errors
}
}, [mountedRef]) // add variable as dependency
I used useEffect to fetch data.
I could not call the function inside effect simply because hooks can not be called inside a function.
useEffect(() => {
fetchSpecificItem(input);
return () => {
mountedRef.current = false; // clean up function
};
}, [input, fetchSpecificItem]); // add function as dependency
Thanks, everyone your contribution helped me to learn more about the usage of hooks.
fetchData is an async function which will return a promise. But you have invoked it without resolving it. If you need to do any cleanup at component unmount, return a function inside the effect that has your cleanup code. Try this :
const Miliko = () => {
const [data, setData] = useState({ hits: [] });
const [url, setUrl] = useState('http://hn.algolia.com/api/v1/search?query=redux');
const [isLoading, setIsLoading] = useState(false);
const [isError, setIsError] = useState(false);
useEffect(() => {
(async function() {
setIsError(false);
setIsLoading(true);
try {
const result = await axios(url);
setData(result.data);
} catch (error) {
setIsError(true);
}
setIsLoading(false);
})();
return function() {
/**
* Add cleanup code here
*/
};
}, [url]);
return [{ data, isLoading, isError }, setUrl];
};
I would suggest reading the official docs where it is clearly explained along with some more configurable parameters.
Folowing #Niyongabo solution, the way I ended up that fixed it was:
const mountedRef = useRef(true);
const fetchSpecificItem = useCallback(async () => {
try {
const ref = await db
.collection('redeems')
.where('rewardItem.id', '==', reward.id)
.get();
const data = ref.docs.map(doc => ({ id: doc.id, ...doc.data() }));
if (!mountedRef.current) return null;
setRedeems(data);
setIsFetching(false);
} catch (error) {
console.log(error);
}
}, [mountedRef]);
useEffect(() => {
fetchSpecificItem();
return () => {
mountedRef.current = false;
};
}, [fetchSpecificItem]);
Create a mutable ref object and set it to true, and during clean-up toggle its value, to ensure that the component has been unmouted.
const mountedRef = useRef(true)
useEffect(() => {
// CALL YOUR API OR ASYNC FUNCTION HERE
return () => { mountedRef.current = false }
}, [])
const [getAllJobs, setgetAlljobs] = useState();
useEffect(() => {
let mounted = true;
axios.get('apiUrl')
.then(function (response) {
const jobData = response.data;
if (mounted) {
setgetAlljobs(jobData)
}
})
.catch(function (error) {
console.log(error.message)
})
return () => mounted = false;
}, [])
set a variable mounted to true->
then if it is true, mount the function->
in the bottom you return it to unmount it
My case was pretty different from what this questions wants. Still I got the same error.
My case was because I had a 'list', which was rendered by using .map from array. And I needed to use .shift. (to remove first item in array)
If array had just one item, it was ok, but since it had 2 of them -> the first one got 'deleted/shifted' and because I used key={index} (while index was from .map), it assumed, that the second item, which later was first, was the same component as the shifted item..
React kept info from the first item (they were all nodes) and so, if that second node used useEffect(), React threw error, that the component is already dismounted, because the former node with index 0 and key 0 had the same key 0 as the second component.
The second component correctly used useEffect, but React assumed, that it is called by that former node, which was no longer on the scene -> resulting in error.
I fixed this by adding different key prop value (not index), but some unique string.
you can wrap any action as a callback inside checkUnmount
const useUnmounted = () => {
const mountedRef = useRef(true);
useEffect(
() => () => {
mountedRef.current = false;
},
[],
);
const checkUnmount = useCallback(
(cb = () => {}) => {
try {
if (!mountedRef.current) throw new Error('Component is unmounted');
cb();
} catch (error) {
console.log({ error });
}
},
[mountedRef.current],
);
return [checkUnmount, mountedRef.current];
};
import React, { useCallback, useEffect, useRef, useState } from "react";
import { userLoginSuccessAction } from "../../../redux/user-redux/actionCreator";
import { IUser } from "../../../models/user";
import { Navigate } from "react-router";
import XTextField from "../../../x-lib/x-components/x-form-controls/XTextField";
import { useDispatch } from "react-redux";
interface Props {
onViewChange?: (n: number) => void;
userInit?: (user: IUser) => void;
}
interface State {
email: string;
password: string;
hasError?: boolean;
errorMessage?: string;
}
const initialValue = {
email: "eve.holt#reqres.in",
password: "cityslicka",
errorMessage: "",
};
const LoginView: React.FC<Props> = (props) => {
const { onViewChange } = props;
const [state, setState] = useState(initialValue);
const mountedRef = useRef(true);
const dispatch = useDispatch();
const handleEmailChange = useCallback(
(val: string) => {
setState((state) => ({
...state,
email: val,
}));
},
[state.email]
);
const handlePasswordChange = useCallback(
(val: string) => {
setState((state) => ({
...state,
password: val,
}));
},
[state.password]
);
const onUserClick = useCallback( async () => {
// HTTP Call
const data = {email: state.email , password: state.password}
try{
await dispatch(userLoginSuccessAction(data));
<Navigate to = '/' />
setState( (state)=>({
...state,
email: "",
password: ""
}))
}
catch(err){
setState( (state)=>({
...state,
errorMessage: err as string
}))
}
},[mountedRef] )
useEffect(()=>{
onUserClick();
return ()=> {
mountedRef.current = false;
};
},[onUserClick]);
const Error = (): JSX.Element => {
return (
<div
className="alert alert-danger"
role="alert"
style={{ width: "516px", margin: "20px auto 0 auto" }}
>
{state.errorMessage}
</div>
);
};
return (
<div>
<div>
email: "eve.holt#reqres.in"
<span style={{ paddingRight: "20px" }}></span> password: "cityslicka"{" "}
</div>
{state.errorMessage && <Error />}
<form className="form-inline">
<div className="form-group">
<XTextField
label="email"
placeholder="E-Posta"
value={state.email}
onChange={handleEmailChange}
/>
</div>
<div className="form-group my-sm-3">
<XTextField
type="password"
label="password"
placeholder="Şifre"
value={state.password}
onChange={handlePasswordChange}
/>
</div>
<button type="button" className="btn btn-primary" onClick = {onUserClick} >
Giriş Et
</button>
<a
href="#"
onClick={(e) => {
e.preventDefault();
onViewChange && onViewChange(3);
}}
>
Şifremi Unuttum!
</a>
</form>
<p>
Hələdə üye deyilsiniz? <br />
pulsuz registir olmak üçün
<b>
<u>
<a
style={{ fontSize: "18px" }}
href="#"
onClick={(e) => {
e.preventDefault();
onViewChange && onViewChange(2);
}}
>
kilik edin.
</a>
</u>
</b>
</p>
</div>
);
};
export default LoginView;
<script src="https://cdnjs.cloudflare.com/ajax/libs/react/16.6.3/umd/react.production.min.js"></script>
<script src="https://cdnjs.cloudflare.com/ajax/libs/react-dom/16.6.3/umd/react-dom.production.min.js"></script>
For this problem I used a tricky way
first I deploy a state like this
const [routing,setRouting] = useState(false)
then when my works finished I changed it to true
and change my useEffect like this
useEffect(()=>{
if(routing)
navigation.navigate('AnotherPage')
),[routing]}

Resources