map() is not rendering html elements - arrays

I had spent 4hrs in this issue but can't figure out what's the problem. Through props I had passed an array(props.content) and wanted to render each element with <h4> tag(not specific) but I can't. It works when I try to console.log each elements of array.
import classes from "./Memes.module.css";
const Memes = (props) => {
return (
<div className={classes.memes__body}>
{Array.prototype.forEach.call(props.content,items=>{
console.log(items)
})}
</div>
);
}
export default Memes;
Output -
but It didn't work when I run the same to render all items in some html tags.
import classes from "./Memes.module.css";
const Memes = (props) => {
return (
<div className={classes.memes__body}>
{Array.prototype.forEach.call(props.content,items=>{
<h1>{items}</h1>
})}
</div>
);
}
export default Memes;
OutPut
Doesn't work.
Note - Here props.content is an array of strings.
Fetch_memes.js (Parent one)
import { useState } from "react";
import { useEffect } from "react";
import Memes from "./Memes";
const Fetch_memes = () => {
const [image, setImage] = useState();
const [text, setText] = useState("");
useEffect(() => {
const memes = async () => {
const response = await fetch('https://www.reddit.com/r/memes.json');
if (!response.ok) {
throw new Error("Something went wrong");
}
const responseData = await response.json();
const img = responseData.data.children[0].data.thumbnail;
const memesCollection = [];
memesCollection.push("If you can Code then this doesn't mean that your are developer");
for(let i=0 ; i<20 ; i++){
memesCollection.push(responseData.data.children[i].data.title);
}
console.log(memesCollection[1]);
setImage(img);
setText(memesCollection);
}
memes();
}, []);
return (
<Memes src={image} content={text}/>
);
}
export default Fetch_memes;

You need to use return in your code:
import classes from "./Memes.module.css";
const Memes = (props) => {
return (
< >
{props.content.map((items)=>{
return <h1>{items}</h1>
})}
</>
);
}
export default Memes;

you can either use
{props.content.map(items=>{
return <h4>{items}</h4>
})}
or replace {} by ()and react returns the value by default:
{props.content.map(items=>(<h4>{items}</h4>))}
UPDATE: try this:
import classes from "./Memes.module.css";
import React from "react"
const Memes = ({content})=>{
return (
<div>
{content.map(item=>(<h1>{item}</h1>))}
</div>
);
}
export default Memes;
let me know the result.

Related

How can I send state to another component in react?

I would like to ask how can I send state from component to another component?
I have 3 components and I want to send data between them. So I have an input component where I handle an IP call and I want to send this shortedLink state to another component, so I can render that data. I don't know that is it clear what I want to do, but I hope so :D
import ShortedLinks from './ShortedLinks'
const testimonials = () => {
return (
<div>
<ShortedLinks />
</div>
);
};
export default testimonials;
const shortedLinks = () => {
return (
<div>
<h1>I want to get the state here</h1>
</div>
);
};
export default shortedLinks;
const InputSection = () => {
const [shortedLink, setShortedLink] = useState("")
return (...);
};
export default InputSection;
You can use the props to achieve it like this :
import ShortedLinks from './ShortedLinks'
const Testimonials = () => {
const [shortedLink, setShortedLink] = useState("")
return (
<div>
<ShortedLinks shortedLink={shortedLink} /> // Pass props here
</div>
);
};
export default Testimonials;
And then in your ShortedLinks component
const ShortedLinks = ({shortedLink}) => { // Get props here
return (
<div>
<h1>{shortedLink}</h1>
</div>
);
};
export default ShortedLinks;
And if you can't use the props like this you can use the useContext like this :
import React,{ useState, createContext } from "react";
export const ShortedLinkContext = createContext('');
const InputSection = () => {
const [shortedLink, setShortedLink] = useState("")
return (
<ShortedLinkContext.Provider value={shortedLink}>
....
</ShortedLinkContext.Provider>
);
};
export default InputSection;
And finally you can comsume the context here :
import {ShortedLinkContext} from ....
const ShortedLinks = () => {
const shortedLink = useContext(ShortedLinkContext);
return (
<div>
<h1>{shortedLink}</h1>
</div>
);
};
export default shortedLinks;
Enjoy :)

Function components cannot have string refs. We recommend using useRef() instead

I'm creating a counter state using useState and useRef. However I'm getting this error
Here's my code
import { useEffect, useRef, useState} from 'react';
const App = () => {
const [clicks, setClick] = useState(0)
const myComponentDiv = useRef(null)
useEffect(() => {
if (myComponentDiv && myComponentDiv.current) {
myComponentDiv.current.addEventListener('click', clickHandler)
return () => {
myComponentDiv.current.removeEventListener('click', clickHandler)
}
}
}, [myComponentDiv]);
const clickHandler = () => {
setClick(clicks + 1)
}
return (
<div className="App">
<div className="my-component" ref="myComponentDiv">
<h2>My Component {clicks} clicks</h2>
</div>
</div>
);
}
export default App;
May i know where i did wrong?
Here:
ref="myComponentDiv"
should be:
ref={myComponentDiv}

Not Rendering Card - React

I'm new to React, and I would like to know if someone can help me?
I'm trying to use useEffect and State to manipulate the API.
But the cards are not rendering.
Sometimes all the cards are rendering, other times not.. and they always come on a different order even after sorting them :( Can you help me?
App.js
/* eslint-disable react-hooks/exhaustive-deps */
import React, { useState, useEffect } from "react";
import PlayerList from "./PlayerList";
import axios from "axios";
function App() {
const Team = [
...
];
const Team2 = [
...
];
const Team3 = [
...
];
const teamForLoop = [Team, Team2, Team3];
const [allPlayers, setAllPlayers] = useState([]);
const [team, setTeam] = useState([]);
const [allTeams] = useState(teamForLoop);
const [loading, setLoading] = useState(true);
useEffect(() => {
const playerInfo = async () => {
setLoading(true);
allTeams.map(async (teamArray) => {
setTeam([]);
teamArray.map(async (player) => {
let playerName = player.split(" ");
const result = await axios.get(
`https://www.thesportsdb.com/api/v1/json/2/searchplayers.php?p=${playerName[0]}%20${playerName[1]}`
);
if (result.data.player === null) {
setTeam((state) => {
return [...state];
});
} else {
setTeam((state) => {
return [...state, result.data.player[0]];
});
}
});
setAllPlayers(team);
});
setLoading(false);
};
playerInfo();
}, [allTeams]);
if (loading) return "...Loading...";
return (
<>
<PlayerList allPlayers={allPlayers} />
</>
);
}
export default App;
PlayerList.js
import React from "react";
export default function PlayerList({ allPlayers }) {
const myData = []
.concat(allPlayers)
.sort((a, b) => (a.strNumber > b.strNumber ? 1 : -1))
.sort((a, b) => (a.idTeam !== b.idTeam ? 1 : -1));
return (
<div>
{myData.map((player, index) => (
<div key={index}>
<div className="playerCard">
<img
className="playerImage"
src={player.strCutout}
alt={`${player.strPlayer}`}
/>
<h1 className="playerName">{player.strPlayer}</h1>
<h2 className="playerNumber">{player.strNumber}</h2>
</div>
</div>
))}
</div>
);
}
Codesandbox link:
"https://codesandbox.io/s/busy-orla-v872kt?file=/src/App.js"

How to create infinite scroll in React and Redux?

import React, {useState, useEffect} from 'react';
import {connect} from 'react-redux';
import {
fetchRecipes
} from '../../store/actions';
import './BeerRecipes.css';
const BeerRecipes = ({recipesData, fetchRecipes}) => {
const [page, setPage] = useState(1);
const [recipes, setRecipes] = useState([]);
const [loading, setLoading] = useState(true);
useEffect(() => {
fetchRecipes();
}, [])
return (
<div className='beer_recipes_block'>
<div className='title_wrapper'>
<h2 className='title'>Beer recipes</h2>
</div>
<div className='beer_recipes'>
<ul className='beer_recipes_items'>
{
recipesData && recipesData.recipes && recipesData.recipes.map(recipe =>
<li className='beer_recipes_item' id={recipe.id}>{recipe.name}</li>
)
}
</ul>
</div>
</div>
);
};
const mapStateToProps = state => {
return {
recipesData: state.recipes
}
}
const mapDispatchToProps = dispatch => {
return {
fetchRecipes: () => dispatch(fetchRecipes())
}
}
export default connect(mapStateToProps, mapDispatchToProps)(BeerRecipes);
this is my component where I would like to create infinite scroll and below is my redux-action with axios:
import axios from "axios";
import * as actionTypes from "./actionTypes";
export const fetchRecipesRequest = () => {
return {
type: actionTypes.FETCH_RECIPES_REQUEST
}
}
export const fetchRecipesSuccess = recipes => {
return {
type: actionTypes.FETCH_RECIPES_SUCCESS,
payload: recipes
}
}
export const fetchRecipesFailure = error => {
return {
type: actionTypes.FETCH_RECIPES_FAILURE,
payload: error
}
}
export const fetchRecipes = (page) => {
return (dispatch) => {
dispatch(fetchRecipesRequest)
axios
.get('https://api.punkapi.com/v2/beers?page=1')
.then(response => {
const recipes = response.data;
dispatch(fetchRecipesSuccess(recipes));
})
.catch(error => {
const errorMsg = error.message;
dispatch(fetchRecipesFailure(errorMsg));
})
}
}
I want to create a scroll. I need, firstly, to display first 10 elements and then to add 5 elements with every loading. I have 25 elements altogether and when the list is done it should start from the first five again.
Assuming you already have everything ready to load your next page. You can probably simplify the entire process by using a package like react-in-viewport so you don't have to deal with all the scroll listeners.
then you use it like this way.
import handleViewport from 'react-in-viewport';
const Block = (props: { inViewport: boolean }) => {
const { inViewport, forwardedRef } = props;
const color = inViewport ? '#217ac0' : '#ff9800';
const text = inViewport ? 'In viewport' : 'Not in viewport';
return (
<div className="viewport-block" ref={forwardedRef}>
<h3>{ text }</h3>
<div style={{ width: '400px', height: '300px', background: color }} />
</div>
);
};
const ViewportBlock = handleViewport(Block, /** options: {}, config: {} **/);
const Component = (props) => (
<div>
<div style={{ height: '100vh' }}>
<h2>Scroll down to make component in viewport</h2>
</div>
<ViewportBlock
onEnterViewport={() => console.log('This is the bottom of the content, lets dispatch to load more post ')}
onLeaveViewport={() => console.log('We can choose not to use this.')} />
</div>
))
What happen here is, it creates a 'div' which is outside the viewport, once it comes into the view port ( it means user already scrolled to the bottom ), you can call a function to load more post.
To Note: Remember to add some kind of throttle to your fetch function.

mobx-react-lite useObserver hook outside of render

I've seen examples of the useObserver hook that look like this:
const Test = () => {
const store = useContext(storeContext);
return useObserver(() => (
<div>
<div>{store.num}</div>
</div>
))
}
But the following works too, and I'd like to know if there's any reason not to use useObserver to return a value that will be used in render rather than to return the render.
const Test = () => {
const store = useContext(storeContext);
var num = useObserver(function (){
return store.num;
});
return (
<div>
<div>{num}</div>
</div>
)
}
Also, I don't get any errors using useObserver twice in the same component. Any problems with something like this?
const Test = () => {
const store = useContext(storeContext);
var num = useObserver(function (){
return store.num;
});
return useObserver(() => (
<div>
<div>{num}</div>
<div>{store.num2}</div>
</div>
))
}
You can use observer method in the component. And use any store you want.
import { observer } from "mobx-react-lite";
import { useStore } from "../../stores/StoreContext";
const Test = observer(() => {
const { myStore } = useStore();
return() => (
<div>
<div>{myStore.num}</div>
<div>{myStore.num2}</div>
</div>
)
}
);
StoreContext.ts
import myStore from './myStore'
export class RootStore{
//Define your stores here. also import them in the imports
myStore = newMyStore(this)
}
export const rootStore = new RootStore();
const StoreContext = React.createContext(rootStore);
export const useStore = () => React.useContext(StoreContext);

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