BlogDetailsPage.js
import { connect } from "react-redux";
import { useParams } from "react-router-dom";
const BlogDetailsPage = (props) => {
const { id } = useParams();
return <div>Blog Details: {}</div>;
};
const mapStateToProps = (state, props) => {
const { id } = useParams();
return {
blog: state.blogs.find((blog) => {
return blog.id === id;
}),
};
};
export default connect(mapStateToProps)(BlogDetailsPage);
How to use mapStateToProps in "useParams()" react-router-dom ?
and whatever links that navigate to /slug path are ended up in BlogDetailsPage.js, Since BlogDetailsPage.js is being nested nowhere else so i couldn't get specific props pass down but route params. From my perspective this is completely wrong but i couldn't figure out a better way to do it.
Compiled with problems:X
ERROR
src\components\BlogDetailsPage.js
Line 11:18: React Hook "useParams" is called in function "mapStateToProps" that is neither a React function component nor a custom React Hook function. React component names must start with an uppercase letter. React Hook names must start with the word "use" react-hooks/rules-of-hooks
Search for the keywords to learn more about each error.```
Issue
React hooks can only be called from React function components or custom React hooks. Here it is being called in a regular Javascript function that is neither a React component or custom hook.
Solutions
Preferred
The preferred method would be to use the React hooks directly in the component. Instead of using the connect Higher Order Component use the useSelector hook to select/access the state.blogs array.
Example:
import { useSelector } from 'react-redux';
import { useParams } from 'react-router-dom';
const BlogDetailsPage = () => {
const { id } = useParams();
const blog = useSelector(state => state.blogs.find(
blog => String(blog.id) === id
));
return <div>Blog Details: {}</div>;
};
export default BlogDetailsPage;
Alternative/Legacy
If you have the need to access path params in any mapStateToProps function, if you are using a lot of oder code for example, then you'll need to create another HOC to access the path params and have them injected as props so they are available in the mapStateToProps function.
Example:
import { useParams, /* other hooks */ } from "react-router-dom";
const withRouter = Component => props => {
const params = useParams();
// other hooks, useLocation, useNavigate, etc..
return <Component {...props} {...{ params, /* other injected props */ }} />;
};
export default withRouter;
...
import { compose } from 'redux';
import { connect } from 'react-redux';
import withRouter from '../path/to/withRouter';
const BlogDetailsPage = ({ blog }) => {
return <div>Blog Details: {}</div>;
};
const mapStateToProps = (state, { params }) => {
const { id } = params || {};
return {
blog: state.blogs.find((blog) => {
return String(blog.id) === id;
}),
};
};
export default compose(
withRouter, // <-- injects a params prop
connect(mapStateToProps) // <-- props.params accessible
)(BlogDetailsPage);
I think, react hook functions are allowed to use inside of react component.
Outside of react components, it's not allowed to use react api hook functions.
Thanks, I'd liked to help you my answer.
Related
I recive a url param from useParams. I want to pass it to a selector using mapStateToProps.
collection.component.jsx
import { useParams } from "react-router-dom";
import { connect } from "react-redux";
import { selectShopCollection } from "../../redux/shop/shop.selectors";
import './collection.styles.scss'
const Collection = ({ collection }) => {
const { collectionId } = useParams();
console.log(collection)
return (
<div>
<h1>{collection}</h1>
</div>
)
}
const mapStateToProps = (state, ownProps) => ({
collection: selectShopCollection(ownProps.match.params.collectionId)(state)
})
export default connect(mapStateToProps)(Collection);
shop.selectors.js
import { createSelector } from "reselect"
const selectShop = state => state.shop
export const selectShopCollections = createSelector([selectShop], shop =>
shop.collections
)
export const selectShopCollection = collectionUrlParam =>
createSelector([selectShopCollections], collections =>
collections.find(collection => collection.id === collectionUrlParam)
)
I guess the problem is that, I cannot pass params using match as react-router-dom v6 does not pass it in props. Is there any other way to pass collectionId to the selector selectShopCollection?
Since Collection is a function component I suggest importing the useSelector hook from react-redux so you can pass the collectionId match param directly. It simplifies the component API. reselect selectors work well with the useSelector hook.
import { useParams } from "react-router-dom";
import { useSelector } from "react-redux";
import { selectShopCollection } from "../../redux/shop/shop.selectors";
import './collection.styles.scss'
const Collection = () => {
const { collectionId } = useParams();
const collection = useSelector(selectShopCollection(collectionId));
console.log(collection);
return (
<div>
<h1>{collection}</h1>
</div>
)
};
export default Collection;
Collection component can be given props by withRouter. But it was deprecated with react-router v6. Hence we need to create our own HOC which wrap our component.
I created a HOC like this:
import { useParams } from "react-router-dom"
const withRouter = WrappedComponent => props => {
const params = useParams()
return (
<WrappedComponent {...props} params={params} />
)
}
export default withRouter;
See this answer for How to get parameter value from react-router-dom v6 in class to see why this HOC was made.
And, we can import the withRouter to the component and use with connect inside compose. Read more on compose. It just returns final function obtained by composing the given functions from right to left.
const mapStateToProps = (state, ownProps) => ({
collection: selectShopCollection(ownProps.params.collectionId)(state)
})
export default compose(withRouter, connect(mapStateToProps))(Collection)
In React Router v5 there was a listen mehtode on the history object.
With the method I wrote a usePathname hook to rerender a component on a path change.
In React Router v6, this method no longer exists. Is there an alternative for something like this? I would hate to use useLocation because it also renders if the state changes, which I don't need in this case.
The hook is used with v5.
import React from "react";
import { useHistory } from "react-router";
export function usePathname(): string {
let [state, setState] = React.useState<string>(window.location.pathname);
const history = useHistory();
React.useLayoutEffect(
() =>
history.listen((locationListener) => setState(locationListener.pathname)),
[history]
);
return state;
}
As mentioned above, useLocation can be used to perform side effects whenever the current location changes.
Here's a simple typescript implementation of my location change "listener" hook. Should help you get the result you're looking for
function useLocationEffect(callback: (location?: Location) => any) {
const location = useLocation();
useEffect(() => {
callback(location);
}, [location, callback]);
}
// usage:
useLocationEffect((location: Location) =>
console.log('changed to ' + location.pathname));
I am using now this code
import { BrowserHistory } from "history";
import React, { useContext } from "react";
import { UNSAFE_NavigationContext } from "react-router-dom";
export default function usePathname(): string {
let [state, setState] = React.useState<string>(window.location.pathname);
const navigation = useContext(UNSAFE_NavigationContext)
.navigator as BrowserHistory;
React.useLayoutEffect(() => {
if (navigation) {
navigation.listen((locationListener) =>
setState(locationListener.location.pathname)
);
}
}, [navigation]);
return state;
}
It seems to work fine
I find using useNavigate and useLocation quite meaningless compared to useHistory in React Rrouter v5.
As a result of these changes, I made a thin custom hook to ease myself from any refactoring.
Just rename the import path to this hook and use the "old" api with v6. To answer or just give hints to your question - using this approach is should be easy to implement the listen function in the custom hook yourself.
export function useHistory() {
const navigate = useNavigate();
const location = useLocation();
const listen = ...; // implement the hook yourself
return {
push: navigate,
go: navigate,
goBack: () => navigate(-1),
goForward: () => navigate(1),
listen,
location,
};
}
Why not simply use const { pathname } = useLocation();? It will indeed renders if the state changes but it shouldn't be a big deal in most scenarii.
If you REALLY want to avoid such behaviour, you could create a context of your own to hold the pathname:
// PathnameProvider.js
import React, { createContext, useContext } from 'react';
import { useLocation } from 'react-router';
const PathnameContext = createContext();
const PathnameProvider = ({ children }) => {
const { pathname } = useLocation();
return (
<PathnameContext.Provider value={pathname}>
{children}
</PathnameContext.Provider>
);
}
const usePathname = () => useContext(PathnameContext);
export { PathnameProvider as default, usePathname };
Then you can use usePathname() in any component down the tree. It will render only if the pathname actually changed.
Given that #kryštof-Řeháček's recommendation (just above) is to implement your own useListen hook, but it might not be obvious how to do that, here's a version I've implemented for myself as a guide (nb: I havent't exhaustively unit tested this yet):
import { useState } from "react";
import { useLocation } from "react-router";
interface HistoryProps {
index: number;
isHistoricRoute: boolean;
key: string;
previousKey: string | null;
}
export const useHistory = (): HistoryProps => {
const { key } = useLocation();
const [history, setHistory] = useState<string[]>([]);
const [currentKey, setCurrentKey] = useState<string | null>(null);
const [previousKey, setPreviousKey] = useState<string | null>(null);
const contemporaneousHistory = history.includes(key)
? history
: [...history, key];
const index = contemporaneousHistory.indexOf(key);
const isHistoricRoute = index + 1 < contemporaneousHistory.length;
const state = { index, isHistoricRoute, key, previousKey };
if (history !== contemporaneousHistory) setHistory(contemporaneousHistory);
if (key !== currentKey) {
setPreviousKey(currentKey);
setCurrentKey(key);
}
return state;
}
I now have just created a new routing library for react where this is possible.
https://github.com/fast-router/fast-router
Server-Side rendering is not supported. The rest should work fine. The library is mainly inspired by wouter -> https://github.com/molefrog/wouter
There are hooks for example usePathname which only cause a new render if the actual pathname changes (ignoring the hash and search)
It is possible to select just a single property of the history.state and don't get a new render if any other values inside the state changes.
I'm using react-router-dom v6 and don't know how to get parameter value
ex: http://localhost:3000/user/:id
i want to get :id
Someone use hook useParams to get but i'm using class so i can't use hook.
The library-provided HOC, withRouter, has been deprecated in React Router v6. If you need to use v6 and are using class-based React components, then you will need to write your own HOC which wraps the v6 use* hooks.
For example:
export function withRouter( Child ) {
return ( props ) => {
const location = useLocation();
const navigate = useNavigate();
return <Child { ...props } navigate={ navigate } location={ location } />;
}
}
This is useful if you have a large code base that you need to move to v6, but haven't migrated all of your class-based components into functional ones.
This is based on the recommendation from the dev team as stated in this Github issue: https://github.com/ReactTraining/react-router/issues/7256 t
Typescript HoC
import React from "react";
import { NavigateFunction, useLocation, useNavigate, useParams } from "react-router";
export interface RoutedProps<Params = any, State = any> {
location: State;
navigate: NavigateFunction;
params: Params;
}
export function withRouter<P extends RoutedProps>( Child: React.ComponentClass<P> ) {
return ( props: Omit<P, keyof RoutedProps> ) => {
const location = useLocation();
const navigate = useNavigate();
const params = useParams();
return <Child { ...props as P } navigate={ navigate } location={ location } params={ params }/>;
}
}
then let the class component props extends RoutedProps with optional Params and State types
If you are using react-redux, this example will help you.
where you are defining your Routes, Use that component as shown:
<Route path="/user" component={ManageUser} />
<Route path="/user/:id" component={ManageUser} />
In this ManageUser component, where you are doing mapStateToProps your can use like this:
function mapStateToProps(state, ownProps) {
const id = ownProps.match.params.id;
// get the user
const contextuser = getUserById(state.users, id);
return {
contextuser; contextuser
};
}
In this way you can pass the User to your component.
import { withRouter } from 'react-router-dom'
export withRouter(YourComponent)
then access this.props.match.params in your component
It is my first application using react context with hooks instead of react-redux and would like to get help of the structure of the application.
(I'm NOT using react-redux or redux-saga libraries.)
Context
const AppContext = createContext({
client,
user,
});
One of actions example
export const userActions = (state, dispatch) => {
function getUsers() {
dispatch({ type: types.GET_USERS });
axios
.get("api address")
.then(function(response) {
dispatch({ type: types.GOT_USERS, payload: response.data });
})
.catch(function(error) {
// handle error
});
}
return {
getUsers,
};
};
Reducer (index.js): I used combineReducer function code from the redux library
const AppReducer = combineReducers({
client: clientReducer,
user: userReducer,
});
Root.js
import React, { useContext, useReducer } from "react";
import AppContext from "./context";
import AppReducer from "./reducers";
import { clientActions } from "./actions/clientActions";
import { userActions } from "./actions/userActions";
import App from "./App";
const Root = () => {
const initialState = useContext(AppContext);
const [state, dispatch] = useReducer(AppReducer, initialState);
const clientDispatch = clientActions(state, dispatch);
const userDispatch = userActions(state, dispatch);
return (
<AppContext.Provider
value={{
clientState: state.client,
userState: state.user,
clientDispatch,
userDispatch,
}}
>
<App />
</AppContext.Provider>
);
};
export default Root;
So, whenever the component wants to access the context store or dispatch an action, this is how I do from the component :
import React, { useContext } from "react";
import ListMenu from "../common/ListMenu";
import List from "./List";
import AppContext from "../../context";
import Frame from "../common/Frame";
const Example = props => {
const { match, history } = props;
const { userState, userDispatch } = useContext(AppContext);
// Push to user detail route /user/userId
const selectUserList = userId => {
history.push(`/user/${userId}`);
userDispatch.clearTabValue(true);
};
return (
<Frame>
<ListMenu
dataList={userState.users}
selectDataList={selectUserList}
/>
<List />
</Frame>
);
};
export default Example;
The problem I faced now is that whenever I dispatch an action or try to access to the context store, the all components are re-rendered since the context provider is wrapping entire app.
I was wondering how to fix this entire re-rendering issue (if it is possible to still use my action/reducer folder structure).
Also, I'm fetching data from the action, but I would like to separate this from the action file as well like how we do on redux-saga structure. I was wondering if anybody know how to separate this without using redux/redux-saga.
Thanks and please let me know if you need any code/file to check.
I once had this re-rendering issue and I found this info on the official website:
https://reactjs.org/docs/context.html#caveats
May it will help you too
This effect (updating components on context update) is described in official documentation.
A component calling useContext will always re-render when the context value changes. If re-rendering the component is expensive, you can optimize it by using memoization
Possible solutions to this also described
I see universal solution is to useMemo
For example
const Example = props => {
const { match, history } = props;
const { userState, userDispatch } = useContext(AppContext);
// Push to user detail route /user/userId
const selectUserList = userId => {
history.push(`/user/${userId}`);
userDispatch.clearTabValue(true);
};
const users = userState.users;
return useMemo(() => {
return <Frame>
<ListMenu
dataList={users}
selectDataList={selectUserList}
/>
<List />
</Frame>
}, [users, selectUserList]); // Here are variables that component depends on
};
I also may recommend you to completly switch to Redux. You're almost there with using combineReducers and dispatch. React-redux now exposes useDispatch and useSelector hooks, so you can make your code very close to what you're doing now (replace useContext with useSelector and useReducer with useDispatch. It will require minor changes to arguments)
Is there a way with new react hooks API to replace a context data fetch?
If you need to load user profile and use it almost everywhere, first you create context and export it:
export const ProfileContext = React.createContext()
Then you import in top component, load data and use provider, like this:
import { ProfileContext } from 'src/shared/ProfileContext'
<ProfileContext.Provider
value={{ profile: profile, reloadProfile: reloadProfile }}
>
<Site />
</ProfileContext.Provider>
Then in some other components you import profile data like this:
import { ProfileContext } from 'src/shared/ProfileContext'
const context = useContext(profile);
But there is a way to export some function with hooks that will have state and share profile with any component that want to get data?
React provides a useContext hook to make use of Context, which has a signature like
const context = useContext(Context);
useContext accepts a context object (the value returned from
React.createContext) and returns the current context value, as given
by the nearest context provider for the given context.
When the provider updates, this Hook will trigger a rerender with the
latest context value.
You can make use of it in your component like
import { ProfileContext } from 'src/shared/ProfileContext'
const Site = () => {
const context = useContext(ProfileContext);
// make use of context values here
}
However if you want to make use of the same context in every component and don't want to import the ProfileContext everywhere you could simply write a custom hook like
import { ProfileContext } from 'src/shared/ProfileContext'
const useProfileContext = () => {
const context = useContext(ProfileContext);
return context;
}
and use it in the components like
const Site = () => {
const context = useProfileContext();
}
However as far a creating a hook which shares data among different component is concerned, Hooks have an instance of the data for them self and don'tshare it unless you make use of Context;
updated:
My previous answer was - You can use custom-hooks with useState for that purpose, but it was wrong because of this fact:
Do two components using the same Hook share state? No. Custom Hooks are a mechanism to reuse stateful logic (such as setting up a subscription and remembering the current value), but every time you use a custom Hook, all state and effects inside of it are fully isolated.
The right answer how to do it with useContext() provided #ShubhamKhatri
Now i use it like this.
Contexts.js - all context export from one place
export { ClickEventContextProvider,ClickEventContext} from '../contexts/ClickEventContext'
export { PopupContextProvider, PopupContext } from '../contexts/PopupContext'
export { ThemeContextProvider, ThemeContext } from '../contexts/ThemeContext'
export { ProfileContextProvider, ProfileContext } from '../contexts/ProfileContext'
export { WindowSizeContextProvider, WindowSizeContext } from '../contexts/WindowSizeContext'
ClickEventContext.js - one of context examples:
import React, { useState, useEffect } from 'react'
export const ClickEventContext = React.createContext(null)
export const ClickEventContextProvider = props => {
const [clickEvent, clickEventSet] = useState(false)
const handleClick = e => clickEventSet(e)
useEffect(() => {
window.addEventListener('click', handleClick)
return () => {
window.removeEventListener('click', handleClick)
}
}, [])
return (
<ClickEventContext.Provider value={{ clickEvent }}>
{props.children}
</ClickEventContext.Provider>
)
}
import and use:
import React, { useContext, useEffect } from 'react'
import { ClickEventContext } from 'shared/Contexts'
export function Modal({ show, children }) {
const { clickEvent } = useContext(ClickEventContext)
useEffect(() => {
console.log(clickEvent.target)
}, [clickEvent])
return <DivModal show={show}>{children}</DivModal>
}