React component doesn't update after updating state with redux action - reactjs

/keywordsActions
import { UPDATE_KEYWORDS } from "./actionTypes";
import queryString from "query-string";
const keywordsArrayFromUrl = () => {
const query = queryString.parse(window.location.search);
if (query.keywords) {
const removeDuplicate = new Set(query.keywords.split(" "));
return Array.from(removeDuplicate);
}
return [];
};
export function updateKeywords() {
return async dispatch => {
dispatch({
type: UPDATE_KEYWORDS,
payload: await keywordsArrayFromUrl()
});
};
}
/keywordReducer
import { UPDATE_KEYWORDS } from "../actions/actionTypes";
export default function(state = [], action) {
switch (action.type) {
case UPDATE_KEYWORDS:
return action.payload;
default:
return state;
}
}
/SearchBar -- React Component
import React, { Component } from "react";
import { withRouter } from "react-router-dom";
//Redux
import { connect } from "react-redux";
import { updateKeywords } from "../store/actions/KeywordsAction";
class Searchbar extends Component {
constructor(props) {
super(props);
this.state = {
keywords : this.props.keywords
keywordsString: this.props.keywords.join(" ")
};
}
componentDidMount() {
this.props.updateKeywords();
console.log(this.props)
setTimeout(() => console.log(this.props), 10);
}
_handleChange = e => {
this.setState({ keywordsString: e.target.value });
};
_handleSearch = value => {
this.setState({ keywordsString: value });
this.props.history.push(`/search?keywords=${value}`);
};
render() {
return (
<Search
className="Searchbar"
placeholder="Cauta prin iBac..."
value={this.state.keywordsString}
onChange={this._handleChange}
onSearch={this._handleSearch}
/>
);
}
}
const mapStateToProps = state => {
return {
keywords: state.keywords
};
};
export default connect(
mapStateToProps,
{ updateKeywords }
)(withRouter(Searchbar));
I want to save the keywords from the Url to the store and then pass it to the Search bar state.
But i dont understand this :
componentDidMount() {
this.props.updateKeywords();
console.log(this.props); // this.props.keywords is empty
setTimeout(() => console.log(this.props), 10); // After 10 ms this.props.keywords is no empty
}
After 10 ms the props of Searchbar gets updated but the component doesn't render again.
Sorry for my question, I am really new to React / Redux. Please let me know what I am doing wrong. Thank you all!
Update :
componentDidMount() {
this.props.updateKeywords();
setTimeout(() => {
this.setState({
keywordsString: this.props.keywords.join(" ")
});
}, 0);
}
This code is also working... but this other is not working
componentDidMount() {
this.props.updateKeywords();
this.setState({
keywordsString: this.props.keywords.join(" ")
});
}

The reason is that componentDidMount is only called once on mount. What you're looking for is either componentShouldUpdate or componentDidUpdate or the render function, all of which are called when your component receives the updated state from redux. You can read here for more information on what these functions do.
https://reactjs.org/docs/react-component.html#updating

Related

how to use map function with (axios/classhooks) to read from API

import React, { Component } from "react";
import axios from "axios";
class Verifry extends Component {
constructor(props) {
super(props);
this.state = {
s: "0",
user: [],
};
}
/* has title as attribute within the res.data*/
async componentDidMount() {
await axios
.get(http://10.0.0.106:8080/kuwait_elections/api/about_us)
.then((res) => {
const persons = res.data;
this.setState({ user: persons.data.title, s: "4" });
console.log(this.state.user);
});
}
componentDidUpdate() {
// this.state.user.map((u) => {
// return u;
// });
}
render() {
return (
{this.state.user.map((t) => {
return {t.title};
})}
);
}
}
export default Verifry;
Seems your return is not correct. It should be like this.
{
this.state.user.map(({title}) => {
return { title };
})
}
Note: Please format your code properly to make it easier to understand.

Redux State null in render method, even after redux state is updated correctly

I am in learning phase of react, and creating small application which fetches user wishlist from firebase table and updated redux store and I am trying to access that redux store in render method but when i console.log this.props.wishlist in render method its shows null. Redux state is updated correctly. Checked with redx dev tool.
redux state screenshot
Action creator which gets wishlist data from firebase API
export const fetchWishlist = (email)=> {
return dispatch => {
dispatch(fetchWishlistStart());
let rawMovieId=[];
let uniqueMovieIdList = [];
const queryParams ='?orderBy="email"&equalTo="'+email+'"';
axios.get('https://movie-project-6fc34.firebaseio.com/wishlist.json'+queryParams)
.then (response=>{
for(let key in response.data){
rawMovieId.push(response.data[key].movieId)
}
uniqueMovieIdList = [ ...new Set(rawMovieId) ];
dispatch(fetchMovieDetailsForWishlist(uniqueMovieIdList))
})
.catch(error=> {
console.log(error);
})
}
}
export const setMovieDetailsForWishlist = (movieDetailsList)=> {
return {
type:actionType.SET_MOVIEDETAILS_WISHLIST,
movieDetailsList:movieDetailsList
}
}
export const fetchMovieDetailsForWishlist = (movieList) => {
return dispatch => {
dispatch(fetchWishlistSuccess());
let updatedMovieList = []
movieList.map((currItem)=>{
let final_api_url = api_url+movieDetails_api_end_point+currItem+api_key+'&language='+language
axios.get(final_api_url)
.then(response=>{
updatedMovieList.push({
title:response.data.title,
movieId:response.data.id,
poster:response.data.poster_path
})
})
.catch(error=>{
console.log(JSON.stringify(error));
})
})
dispatch(setMovieDetailsForWishlist(updatedMovieList));
}
}
WhislistReducer --
import * as actionType from '../actions/actionType.js'
const intialState = {
wishList:null,
showLoader:false
}
const wishListReducer = (state=intialState, action) => {
switch (action.type) {
case actionType.FETCH_WISHLIST_START:
return {
...state,
showLoader:true
}
case actionType.FETCH_WISHLIST_SUCCESS:
return {
...state,
showLoader:false
}
case actionType.SET_MOVIEDETAILS_WISHLIST:
return {
...state,
showLoader:false,
wishList:action.movieDetailsList
}
default:
return state
}
}
export default wishListReducer;
wishlist component
import React, { Component } from 'react';
import {connect} from 'react-redux';
import {withRouter} from 'react-router-dom';
import * as action from '../store/actions/index'
export class Wishlist extends Component {
componentDidMount() {
this.props.fetchWishlist(window.localStorage.getItem('email'));
render() {
let wishListPageContent = '<div> Loading........</div>'
let userWishlistDetails = this.props.wishlist
console.log(userWishlistDetails);
if (!this.props.showLoader) {
wishListPageContent = (
<div> wishlist component</div>
)
}
return (
<div>
{wishListPageContent}
</div>
);
}
}
const mapStateToProps = state => {
return {
userEmail:state.authState.userEmail,
wishlist:state.wishlistState.wishList,
isAuthSuccess:state.authState.isAuthSuccess,
showLoader:state.wishlistState.showLoader
}
}
const mapDispatchToProps = dispatch => {
return {
fetchWishlist:(email)=>dispatch(action.fetchWishlist(email)),
fetchMovieDetailsForWishlist:(movieList)=>dispatch(action.fetchMovieDetailsForWishlist(movieList))
}
}
export default withRouter(connect(mapStateToProps,mapDispatchToProps)(Wishlist));

React + Axios - Map returns is not a function?

I'm working on my first API with React. I am able to console log my current state after its loaded and the state for that array is set. However, running my component with a prop "FragrancesArray" which is set after loading the data from this.state.fragrances returns in not a function.
Using axios async and await.
No idea why? Can someone help?
Thanks.
My code:
// Core React
import React, { Component } from 'react';
// Axios
import axios from 'axios';
// Constants
import { FRAGRANCES_URL, BLOGS_URL, MAKE_UP_URL } from 'constants/import';
// Components
import Fragrances from 'components/Fragrances/Fragrances';
class App extends Component {
state = {
fragrances: [],
blogs: [],
makeup: []
}
getCoffee() {
return new Promise(resolve => {
setTimeout(() => resolve('☕'), 0); // it takes 1 seconds to make coffee
});
}
async showData() {
try {
// Coffee first
const coffee = await this.getCoffee();
console.log(coffee); // ☕
// Axios API's
const fragranceData = axios(FRAGRANCES_URL);
const blogData = axios(BLOGS_URL);
const makeupData = axios(MAKE_UP_URL);
// await all three promises to come back and destructure the result into their own variables
await Promise.all([fragranceData, blogData, makeupData])
.then((data) => {
this.setState({
fragrances: data[0],
blogs: data[1],
makeup: data[2]
});
const { blogs } = this.state;
console.log(blogs);
})
} catch (e) {
console.error(e); // 💩
}
}
componentDidMount() {
this.showData();
}
render() {
return (
<Fragrances FragranceArray={this.state.fragrances} AppURL={FRAGRANCES_URL} />
)
}
}
export default App;
In react, before you can set/use state, you need to declare it with getInitialState() but with ES6 class model you initialize state in a constructor.
class App extends Component {
constructor(props) {
super(props)
//- Initialize default state values
this.state = {
fragrances: [],
blogs: [],
makeup: []
}
}
//The rest of code stays the same.
render() {
return (
<Fragrances FragranceArray={this.state.fragrances} AppURL={FRAGRANCES_URL} />
)
}
}
More about React state

React doesn't update the view even when Redux state is changed

The problem is when I update state in Redux, React doesn't run the render function. I am a beginner in Redux so I am not getting what exactly should I be doing to solve this. I read about the #connect function but as I am using CreateReactApp CLI tool, I won't be able to provide support for Decorators without ejecting (Which I dont want to do).
Component:
import React from "react";
import Store from "../store";
Store.subscribe(() => {
console.log(Store.getState().Auth);
});
export default class Login extends React.Component {
login = () => {
Store.dispatch({ type: "AUTH_LOGIN" });
// this.forceUpdate(); If I forceUpdate the view, then it works fine
};
logout = () => {
Store.dispatch({ type: "AUTH_LOGOUT" });
// this.forceUpdate(); If I forceUpdate the view, then it works fine
};
render() {
if (Store.getState().Auth.isLoggedIn) {
return <button onClick={this.logout}>Logout</button>;
} else {
return <button onClick={this.login}>Login</button>;
}
}
}
Reducer:
export default AuthReducer = (
state = {
isLoggedIn: false
},
action
) => {
switch (action.type) {
case "AUTH_LOGIN": {
return { ...state, isLoggedIn: true };
}
case "AUTH_LOGOUT": {
return { ...state, isLoggedIn: false };
}
}
return state;
};
Can anyone please point me in the right direction? Thanks
You can make use of connect HOC instead of decorator, it would be implemented like
import { Provider, connect } from 'react-redux';
import Store from "../store";
class App extends React.Component {
render() {
<Provider store={store}>
{/* Your routes here */}
</Provider>
}
}
import React from "react";
//action creator
const authLogin = () => {
return { type: "AUTH_LOGIN" }
}
const authLogout = () => {
return { type: "AUTH_LOGOUT" }
}
class Login extends React.Component {
login = () => {
this.props.authLogin();
};
logout = () => {
this.props.authLogout();
};
render() {
if (this.props.Auth.isLoggedIn) {
return <button onClick={this.logout}>Logout</button>;
} else {
return <button onClick={this.login}>Login</button>;
}
}
}
const mapStateToProps(state) {
return {
Auth: state.Auth
}
}
export default connect(mapStateToProps, {authLogin, authLogout})(Login);

react-lifecycle-component have props in componentDidMount

I'm using react-lifecycle-component in my react app, and incurred in this situation where I need the componentDidMount callback to load some data from the backend. To know what to load I need the props, and I can't find a way to retrieve them.
here's my container component:
import { connectWithLifecycle } from "react-lifecycle-component";
import inspect from "../../../libs/inspect";
import fetchItem from "../actions/itemActions";
import ItemDetails from "../components/ItemDetails";
const componentDidMount = () => {
return fetchItem(props.match.params.number);
};
// Which part of the Redux global state does our component want to receive as props?
const mapStateToProps = (state, props) => {
return {
item: state.item,
user_location: state.user_location
};
};
// const actions = Object.assign(locationActions, lifecycleMethods);
export default connectWithLifecycle(mapStateToProps, { componentDidMount })(
ItemDetails
);
Any clues?
thanks.
import React, { Component } from 'react'
import { connect } from 'react-redux'
import fetchItem from '../actions/itemActions'
class Container extends Component {
state = {
items: []
}
componentDidMount() {
const { match } = this.props
fetchItem(match.params.number)
// if your fetchItem returns a promise
.then(response => this.setState({items: response.items}))
}
render() {
const { items } = this.state
return (
<div>
{ items.length === 0 ? <h2>Loading Items</h2> :
items.map((item, i) => (
<ul key={i}>item</ul>
))
}
</div>
)
}
const mapStateToProps = (state, props) => {
return {
item: state.item,
user_location: state.user_location
}
}
export default connect(mapStateToProps)(Container)
Though I don't see where you are using the props you take from your Redux store...

Resources