Develop Reference

While rendering a component it is showing an error- "Cannot update a component (`App`) while rendering a different component (`EventList`). "

I Can't render my events. Its showing this error -
"Cannot update a component (App) while rendering a different component (EventList). To locate the bad setState() call inside EventList, follow the stack trace as described in https://reactjs.org/link/setstate-in-render"
Here is EventList Component code -
import { useEffect, useState } from "react";
import EventList from "../../event-list";
import EventForm from "../event-form";
const EventAction = ({
getEventsByClockID,
addEvent,
updateEvent,
clockID,
deleteEvent,
deleteEventsByClockID,
}) => {
const [isCreate, setIsCreate] = useState(false);
const [isToggle, setIsToggle] = useState(false);
const [eventState, setEventState] = useState(null)
const handleCreate = () => {
setIsCreate(!isCreate);
}
useEffect(() => {
setEventState(getEventsByClockID(clockID, true));
}, [isToggle])
const handleToggle = () => {
setIsToggle(!isToggle);
}
return (
<div>
<div>
<button onClick={handleCreate}>Create Event</button>
<button onClick={handleToggle}>Toggle Events</button>
</div>
{isCreate && (
<>
<h3>Create Event</h3>
<EventForm
clockID={clockID}
handleEvent={addEvent}
/>
</>
)}
{isToggle && (
<>
<h3>Events of this clock</h3>
<EventList
clockID={clockID}
eventState={eventState}
deleteEvent={deleteEvent}
updateEvent={updateEvent}
deleteEventsByClockID={deleteEventsByClockID}
/>
</>
)}
</div>
)
}
export default EventAction;
Here is my App Component Code -
import ClockList from "./components/clock-list";
import LocalClock from "./components/local-clock";
import useApp from "./hooks/useApp";
import { localClockInitState } from "./initialStates/clockInitState";
const App = () => {
const {
localClock,
clocks,
updateLocalClock,
createClock,
updateClock,
deleteClock,
getEventsByClockID,
addEvent,
deleteEvent,
updateEvent,
deleteEventsByClockID,
} = useApp(localClockInitState);
return (
<div>
<LocalClock
clock={localClock}
updateClock={updateLocalClock}
createClock={createClock}
/>
<ClockList
clocks={clocks}
localClock={localClock.date}
updateClock={updateClock}
deleteClock={deleteClock}
getEventsByClockID={getEventsByClockID}
addEvent={addEvent}
deleteEvent={deleteEvent}
updateEvent={updateEvent}
deleteEventsByClockID={deleteEventsByClockID}
/>
</div>
)
}
export default App;
and Here is my useApp hook -
import { useState } from "react";
import deepClone from "../utils/deepClone";
import generateID from "../utils/generateId";
import useEvents from "./useEvents";
const getID = generateID('clock');
const useApp = (initValue) => {
const [localClock, setLocalClock] = useState(deepClone(initValue));
const [clocks, setClocks] = useState([]);
const {
// events,
// getEvents,
getEventsByClockID,
addEvent,
deleteEvent,
deleteEventsByClockID,
updateEvent,
} = useEvents();
const updateLocalClock = (data) => {
setLocalClock({
...localClock,
...data,
})
}
const createClock = (clock) => {
clock.id = getID.next().value;
setClocks((prev) => ([
...prev, clock
]))
}
const updateClock = (updatedClock) => {
setClocks(clocks.map(clock => {
if(clock.id === updatedClock.id) return updatedClock;
return clock;
}));
}
const deleteClock = (id) => {
setClocks(clocks.filter(clock => clock.id !== id));
}
return {
localClock,
clocks,
updateLocalClock,
createClock,
updateClock,
deleteClock,
getEventsByClockID,
addEvent,
deleteEvent,
updateEvent,
deleteEventsByClockID,
}
}
export default useApp;
I want to show all events incorporated with each individual clock.

How to create "More" button on React?

I have React components :
Main.jsx
import { useState, useEffect } from "react";
import { Preloader } from "../Preloader";
import { Pokemons } from "../Pokemons";
import { LoadMore } from "../LoadMore";
function Main() {
const [pokemons, setPokemons] = useState([]);
const [loading, setLoading] = useState(true);
const [pokemonsPerPage] = useState("20");
const [pokemonOffset] = useState("0");
useEffect(function getPokemons() {
fetch(
`https://pokeapi.co/api/v2/pokemon?limit=${pokemonsPerPage}&offset=${pokemonOffset}`
)
.then((responce) => responce.json())
.then((data) => {
data.results && setPokemons(data.results);
setLoading(false);
});
}, []);
return (
<main className="container content">
{loading ? <Preloader /> : <Pokemons pokemons={pokemons} />}
<LoadMore />
</main>
);
}
export { Main };
LoadMore.jsx
import React from 'react'
function LoadMore() {
return (
<div className="button_container">
<a class="waves-effect waves-light btn-large" id="more">
More...
</a>
</div>
);
}
export { LoadMore };
I have created a button in the component. After clicking on it, the next 20 elements should be loaded. I created const [pokemonsPerPage] = useState("20"); and const [pokemonOffset] = useState("0"); in order to substitute these values into the request. The first is responsible for the number of objects on the page, the second is responsible for which element to start counting from. That is, now 20 elements are being output, starting from the very first one. (If you change const [pokemonOffset] = useState("0"); to 20, then the output will start from 21 elements). I'm sure that this is necessary for implementation, but I don't know what to do next
Help me complete this functionality

Here is what your Main.jsx should look like.
import { useState, useEffect } from "react";
import { Preloader } from "../Preloader";
import { Pokemons } from "../Pokemons";
import { LoadMore } from "../LoadMore";
function Main() {
const [pokemons, setPokemons] = useState([]);
const [loading, setLoading] = useState(true);
const [pokemonsPerPage] = useState(20);
const [page,setPage] = useState(1);
function getPokemons(pokemonOffset) {
fetch(
`https://pokeapi.co/api/v2/pokemon?limit=${pokemonsPerPage}&offset=${pokemonOffset}`
)
.then((responce) => responce.json())
.then((data) => {
data.results && setPokemons(data.results);
setLoading(false);
});
}
useEffect(() => {
const offset= page*pokemonsPerPage -pokemonsPerPage;
getPokemons(offset);
}, [page]);
return (
<main className="container content">
{loading ? <Preloader /> : <Pokemons pokemons={pokemons} />}
<LoadMore next={()=>setPage(p=>p+1)} />
</main>
);
}
export { Main };
while your Loadmore.jsx
import React from 'react'
function LoadMore(next) {
return (
<div className="button_container">
<a type="button" onclick={next} class="waves-effect waves-light btn-large" id="more">
More...
</a>
</div>
);
}
export { LoadMore };

maybeStripe.apply is not a function

Ahoy,
Getting an error with Stripe in Gatsby occurs on page load
Uncaught (in promise) TypeError: maybeStripe.apply is not a function
import React, { useEffect, useState } from 'react';
import { loadStripe } from '#stripe/stripe-js';
import { Elements } from '#stripe/react-stripe-js';
import StripeCheckout from './stripeCheckout'
const stripePromise = loadStripe('pk_test_xyz');
function App() {
const [clientSecret, setClientSecret] = useState('');
useEffect(() => {
fetch("/.netlify/functions/createIntent")
.then((res) => res.json())
.then(({ clientSecret }) => setClientSecret(clientSecret));
}, [])
const options = {
clientSecret,
}
return (
<main>
<h1>Payment</h1>
{clientSecret && (
<Elements stripe={stripePromise} options={options}>
<StripeCheckout />
</Elements>
)}
</main>
);
}
export default App;
import {
PaymentElement
} from '#stripe/react-stripe-js'
import React, {useState} from 'react'
import {useStripe, useElements} from '#stripe/react-stripe-js';
export default function CheckoutForm() {
const stripe = useStripe();
const elements = useElements();
const [message, setMessage] = useState(null);
const [isLoading, setIsLoading] = useState(false);
const handleSubmit = async (e) => {
e.preventDefault();
if (!stripe || !elements) {
return;
}
setIsLoading(true);
const { error } = await stripe.confirmPayment({
elements,
confirmParams: {
// Make sure to change this to your payment completion page
return_url: "http://localhost:8888",
},
});
if (error.type === "card_error" || error.type === "validation_error") {
setMessage(error.message);
} else {
setMessage("An unexpected error occured.");
}
setIsLoading(false);
}
return (
<form id="payment-form" onSubmit={handleSubmit}>
<PaymentElement id="payment-element" />
<button disabled={isLoading || !stripe || !elements} id="submit">
<span id="button-text">
{isLoading ? <div className="spinner" id="spinner"></div> : "Pay now"}
</span>
</button>
{message && <div id="payment-message">{message}</div>}
</form>
)
}
Can't seem to find any ref's to this issue on here or stripes documentation, not sure if this is a Gatsby issue or I am just doing something wrong.
Any help is greatly appreciated
cheers

Removed node_modules and reinstalled and added import { loadStripe } from '#stripe/stripe-js/pure';

You may have installed other modules like #stripe/stripe-js but I don't think you installed the main stripe module. So run npm i stripe or yarn add stripe and the error will be fixed

How to pass data from child to parent and render content based on selected value in dropdown?

I am learning React as I am fetching data from Pokéapi to make a list component, card component, detail component and filter component. I am trying to make a filter so you can filter by pokémon type. Only the cards that also contain that type string should then render (Not there yet). So I am not sure if a) I should make a different call from API inside PokemonList depending on selected value or b) if I should compare the values and just change how the PokemonCard element is rendered inside PokemonList.js depending on the comparison. I managed to pass data from filter to the list component. I have then been trying to pass the type data from PokemonCard.js to the list component so that I can compare these two values but I find it hard to use callbacks to pass the type data from the card component, since I dont pass it through an event or something like that.
Which method should I use here to simplify the filtering? Make different API call or render PokemonCard element conditionally?
Is it a good idea to compare filter option to pokemon card's type in PokemonList.js? Then how can I pass that data from the card component since I don't pass it through click event?
Thankful for any ideas! I paste the code from list component that contains the cards, card component and filter component.
PokemonList component:
import { useState } from 'react';
import useSWR from 'swr';
import PokemonCard from './PokemonCard';
import PokemonFilter from './PokemonFilter';
import './PokemonList.css';
const PokemonList = () => {
const [index, setIndex] = useState(0);
const [type, setType] = useState('');
function selectedType(type) { // value from filter dropdown
setType(type)
console.log("handled")
console.log(type)
}
const url = `https://pokeapi.co/api/v2/pokemon?limit=9&offset=${index}`;
const fetcher = (...args) => fetch(...args).then((res) => res.json())
const { data: result, error } = useSWR(url, fetcher);
if (error) return <div>failed to load</div>
if (!result) return <div>loading...</div>
result.results.sort((a, b) => a.name < b.name ? -1 : 1);
return (
<section>
<PokemonFilter onSelectedType={selectedType} selectedPokemonType={type} />
<div className="pokemon-list">
<div className="pokemons">
{result.results.map((pokemon) => (
<PokemonCard key={pokemon.name} pokemon={pokemon} /> // callback needed??
))}
</div>
<div className="pagination">
<button
onClick={() => setIndex(index - 9)}
disabled={result.previous === null}
>
Previous
</button>
<button
onClick={() => setIndex(index + 9)}
disabled={result.next === null}
>
Next
</button>
</div>
</div>
</section>
)
}
export default PokemonList;
PokemonCard component:
import { Link } from "react-router-dom";
import useSWR from 'swr';
import './PokemonCard.css';
const PokemonCard = ({ pokemon }) => {
const { name } = pokemon;
const url = `https://pokeapi.co/api/v2/pokemon/${name}`;
const { data, error } = useSWR(url);
if (error) return <div>failed to load</div>
if (!data) return <div>loading...</div>
const { types, abilities } = data;
// types[0].type.name <---- value I want to pass to PokemonList.js
return (
<div className='pokemon-card'>
<div className='pokemon-card__content'>
<img
className='pokemon-card__image'
src={data.sprites.front_default}
alt={name}
/>
<div className='pokemon-card__info'>
<p className='pokemon-card__name'>Name: {name}</p>
<p className='pokemon-card__abilities'>Abilities: {abilities[0].ability.name}</p>
<p className='pokemon-card__categories'>Category: {types[0].type.name}</p>
</div>
</div>
<Link className='pokemon-card__link' to={{
pathname: `/${name}`,
state: data
}}>
View Details
</Link>
</div>
)
}
export default PokemonCard;
PokemonFilter component:
import './PokemonFilter.css';
import useSWR from 'swr';
const PokemonFilter = ({onSelectedType, selectedPokemonType}) => {
const url = `https://pokeapi.co/api/v2/type/`;
const fetcher = (...args) => fetch(...args).then((res) => res.json())
const { data: result, error } = useSWR(url, fetcher);
if (error) return <div>failed to load</div>
if (!result) return <div>loading...</div>
function filteredTypeHandler(e) {
console.log(e.target.value);
onSelectedType(e.target.value);
}
console.log(selectedPokemonType)
return(
<div className="pokemon-types__sidebar">
<h2>Filter Pokémon by type</h2>
<select
name="pokemon-type"
className="pokemon-types__filter"
onChange={filteredTypeHandler}
>
<option value="All">Filter By Type</option>
{result.results.map((type) => {
return (
<option key={type.name} value={type.name}> {type.name}</option>
)
})}
</select>
</div>
)
}
export default PokemonFilter;

Here is an example to improve, modify, ... I didn't test, it's just a visual example.
I don't know about useSWR sorry, I use axios in my example...
If you want to centralize all your API requests, you can create a useApi hook, on the internet you will find tutorials.
PokemonList.js
import React, { useState, useEffect } from 'react';
import axios from 'axios'; // or swr
import PokemonFilter from './PokemonFilter';
import PokemonCard from './PokemonCard';
export default function PokemonList() {
const [data, setData] = useState([]);
const [filter, setFilter] = useState('');
// Executed every first render
useEffect(() => {
getData();
}, []);
// Executed only when filter changes
useEffect(() => {
getDataByTypes(filter);
}, [filter]);
// Get data
const getData = async () => {
const uri = 'https://xxx';
try {
const response = await axios.get(uri);
setData(response.data...);
} catch (error) {
console.log(error);
}
};
// Get data by types
const getDataByTypes = async (filter) => {
const uri = `https://xxx/type/${filter}...`;
if (filter) {
try {
const response = await axios.get(uri);
setData(response.data...);
} catch (error) {
console.log(error);
}
}
};
return (
<div className="main">
<PokemonFilter filter={filter} setFilter={setFilter} />
<div className="container">
<div className="cards-container">
{data.map((d) => (
<PokemonCard key={d.name} data={d} />
))}
</div>
</div>
</div>
);
}
PokemonCard.js
import React, { useState, useEffect } from 'react';
import axios from 'axios';
export default function PokemonCard({ data }) {
const [pokemons, setPokemons] = useState();
useEffect(() => {
getPokemons(data);
}, [data]);
// Get Pokemons
const getPokemons = async (data) => {
const uri = `https://xxx/pokemon/${data.name}/`;
try {
const response = await axios.get(uri);
setPokemons(response.data...);
} catch (error) {
console.log(error);
}
};
return (
<div>
{pokemons && (
<div className="card">
<img src={pokemons.sprites.front_default} alt={pokemons.name} />
<p>{pokemons.name}</p>
<p>{pokemons.abilities[0].ability.name}</p>
<p>{pokemons.types[0].type.name}</p>
</div>
)}
</div>
);
}
PokemonFilter.js
import React, { useState, useEffect } from 'react';
import axios from 'axios';
export default function PokemonFilter({ filter, setFilter }) {
const [types, setTypes] = useState([]);
useEffect(() => {
getType();
}, []);
// Get Type
const getType = async () => {
const uri = 'https://xxx/type/';
try {
const response = await axios.get(uri);
setTypes(response.data.results....);
} catch (error) {
console.log(error);
}
};
const handleFilter = (e) => {
setFilter(e.target.value);
};
return (
<select onChange={handleFilter} value={filter}>
<option>Filter by type</option>
{types.map((type) => {
return (
<option key={type.name} value={type.name}>
{type.name}
</option>
);
})}
</select>
);
}

How to test for props initial values?

I have a header component which listens for loggedInUser data from Redux store. I want to unit test for redux prop values. Like i have mocked a redux store for initial values and want to test for those values in props of the connected component.
import React, { useState } from 'react';
import { connect } from 'react-redux';
import { FontAwesomeIcon } from '#fortawesome/react-fontawesome';
import { faUser, faShoppingCart } from '#fortawesome/free-solid-svg-icons';
import { NavLink, useHistory } from 'react-router-dom';
import Cart from './../Cart/Cart.component';
import { signOutStart } from './../../redux/user/user.actions';
import './Header.styles.scss';
export const Header = ({ noOfItemsInCart, loggedInUser, signOut }) => {
const [isUserDropDownVisible, setUserDropDownVisibility] = useState(false);
const [isCartDropDownVisible, setCartDropDownVisibility] = useState(false);
const history = useHistory();
console.log(loggedInUser);
return (
<header className = 'header' id = 'header'>
<NavLink to = '/'><p className = 'title'>Kart</p></NavLink>
{loggedInUser ? (
<div className = 'header__options' id = 'header__options'>
<div className = 'cart__options'>
<FontAwesomeIcon
icon={faShoppingCart}
onClick = {() => {
setUserDropDownVisibility(false);
setCartDropDownVisibility(prevState => {return !prevState})}
} />
<span><sup>{noOfItemsInCart}</sup></span>
{isCartDropDownVisible ? (
<div className="dropdown">
<Cart />
</div>
) : null}
</div>
<div className = 'user__options'>
<FontAwesomeIcon
icon={faUser}
onClick = {() => {
setCartDropDownVisibility(false);
setUserDropDownVisibility(prevState => {return !prevState})}
} />
{isUserDropDownVisible ? (
<div className="dropdown" onClick = {() => setUserDropDownVisibility(false)}>
<NavLink to = '/orders'>My Orders</NavLink>
<span onClick = { async () => {
await signOut();
history.push('/auth');
} }>Logout</span>
</div>
) : null}
</div>
</div>
) : null}
</header>
)
}
const mapStateToProps = state => {
return {
loggedInUser: state.user.loggedInUser,
noOfItemsInCart: state.cart.noOfItemsInCart
}
}
const mapDispatchToProps = dispatch => {
return {
signOut: () => dispatch(signOutStart())
}
}
export default connect(mapStateToProps, mapDispatchToProps)(Header);
I had implemented an unit test as follows, by using a shallow render of component and tried accessing the props using .props()
import React from 'react';
import { shallow } from 'enzyme';
import configureMockStore from 'redux-mock-store';
import Header from './Header.component';
const mockStore = configureMockStore();
describe('<Header />', () => {
let wrapper, store;
beforeEach(() => {
const initialState = {
user: {
loggedInUser: 'user1',
error: null
},
cart: {
noOfCartItemsInCart: 0
}
}
store = mockStore(initialState);
wrapper = shallow(
<Header store = {store} />
)
});
it('should have valid props', () => {
expect(wrapper.props().loggedInUser).toBe('user1');
})
})
I am getting prop values a undefined or null values. How to test for prop values to an redux connected component?

Have you tried this from the docs?
wrapper.instance().props