Recently I made a question about this problem: typeError: Cannot read property 'map' of undefined.
I want to use a component with getStaticProps and put it in my pages/index.js, but I can't with my current code. BUT, if I put this component as a page (pages/component.js) and open like a different page it just work as it should do.
The component Galery.js code:
import styles from '../styles/galery.module.css'
import Image from 'next/image'
import Link from 'next/link'
import photo from '../public/01.png'
export const getStaticProps = async () => {
const res = await fetch('https://my-json-server.typicode.com/Leterinho/PortfolioInteriorDesign/card');
const datas = await res.json();
return {
props: { datas }
}
}
const Galery = ({ datas }) => {
return (
<div className={styles.galeryPage}>
<h1 className={styles.title}>Projetos</h1>
<div className={styles.galery}>
<div className={styles.categoryWrapper}>
<h4 className={styles.subTitle}>Escritório</h4>
<div className={styles.lineWrapper}>
<a className={styles.leftArrow}>❮</a>
<div className={styles.line}>
{datas.map((data) => (
<div className={styles.imageBox}>
<Image src={photo} width={400} height={200} layout="responsive" lazy="true" placeholder="blur" />
<div className={styles.linkContent}>
<span className={styles.name} key={data.id}>{data.name}</span>
<Link href=""><a className={styles.link}>Veja Mais!</a></Link>
</div>
</div>
))}
</div>
<a className={styles.rightArrow}>❯</a>
</div>
</div>
</div>
</div>
);
}
export default Galery;
API link: https://my-json-server.typicode.com/Leterinho/PortfolioInteriorDesign/card
And this is the structure that I would like to have:
Desirable Structure
And this is the structure that works as a page:
Structure that works
What I should do to work as I planned?
Data fetching methods like getStaticProps can only be used from page components (components inside pages folder). I'd suggest you fetch the data at the page level in index.js, and pass it down to your Galery component.
juliomalves is correct! Thanks.
Related
I added a weather component in my app that fetches weather from open weather map. It works fine until I refresh the page, then it breaks.
If I comment the weather component out when refreshing and then add it back in when loaded it renders and works.
I'm not sure what's causing this error.
Here's some images of the console after refreshing for reference.
It seems to be undefined when refreshed. What's causing this issue?
// Weather component is called as normal in Home page
<div className="main-section-one">
<Weather />
<ToDoWidget />
</div>
import React, { useEffect, useState } from 'react'
//CSS
import '../css/Weather.css'
function Weather() {
// API
const URL = 'https://api.openweathermap.org/data/2.5/weather?q=barcelona&appid=APIKEY';
// State
const [weatherDetails, setWeatherDetails] = useState({});
async function getWeather() {
let fetchUrl = await fetch('https://api.openweathermap.org/data/2.5/weather?q=barcelona&appid=APIKEY&units=metric');
let data = await fetchUrl.json()
setWeatherDetails(data)
}
//Use Effect
useEffect(() => {
getWeather();
}, [])
return (
<div className="weather-container">
<div className="weather-one">
<div className="city">
<h3>Barcelona</h3>
<h1 className='temp'>{weatherDetails.main.temp}°C</h1>
</div>
<div className="current-weather">
<h3 className='current'>Sunny</h3>
</div>
</div>
<div className="weather-two">
<div className="">
<p>{weatherDetails.main.feels_like}°C</p>
<p className='weather-details'>Feels Like</p>
</div>
<div className="">
<p>{weatherDetails.main.humidity}%</p>
<p className='weather-details'>Humidity</p>
</div>
<div className="">
<p>{weatherDetails.wind.speed} MPH</p>
<p className='weather-details'>Wind Speed</p>
</div>
</div>
</div>
)
}
export default Weather
The main and wind properties may be undefined. Secure it.
<h1 className='temp'>{weatherDetails.main?.temp}°C</h1>
^^^ optional chaining
<p>{weatherDetails.wind?.speed} MPH</p>
Reference: Optional chaining
I have these div cards with some information, and I would like to insert a link inside them, that redirects to another site. It didn't work with <a></a>. can anybody help me?
Thanks!
import React from "react";
function Card(props) {
return (
<div className="card">
<img className="img-logo" src={props.img} alt="image_logo" />
<h3 className="name"> {props.name}</h3>
<p className="paragraph"> {props.description}</p>
<a href={props.link}>Page</a>
</div>
);
}
export default Card;
You can use the <Link> component from react router.
If you are opening the url in new tab, make sure to use noopener and noreferrer so that the browser does not attach the current website's window variable to the newly opened url in the new tab, which can be a security loophole.
import { Link } from 'react-router-dom';
export const openInNewTab = (url) => {
const newWindow = window.open(url, '_blank', 'noopener,noreferrer');
if (newWindow) newWindow.opener = null;
};
function Card(props) {
return (
<div className="card">
<img className="img-logo" src={props.img} alt="image_logo" />
<h3 className="name"> {props.name}</h3>
<p className="paragraph"> {props.description}</p>
<Link href="#" onClick = {() => openInNewTab(props.link)}>Page</Link>
</div>
);
}
I am trying to render a headshot for each artist displayed on the page. The artist data comes from a Json file, and the images are located in images/artists/headshots. I am using the regular img tag, but for some reason nothing is displaying on the page. Any help any one can give would be greatly appreciated.
import React from 'react'
import PropTypes from 'prop-types'
import { StaticImage } from 'gatsby-plugin-image'
import { useStyles } from './styles'
const ArtistsPage = ({ data }) => {
const classes = useStyles()
return (
<section>
<article className={classes.artistsBackground}>
<div className={classes.heroLayoutContainer}>
<h3 className={classes.title}>MEET THE ARTISTS</h3>
<StaticImage
className={classes.heroImage}
src='../../images/artists/hero-images/hero-image-artists.jpg'
alt='hero-image-artists'
placeholder='blurred'
/>
</div>
</article>
<article className={classes.artistsContainer}>
<div className={classes.flexContainer}>
{data.allArtistsJson.edges
.map(({ node }, idx) => {
const artist = `${node.firstName}+${node.lastName}`
.split('+')
.join(' ')
return (
<div className={classes.flexItem} key={idx}>
<div>
<img
src={`../../images/artists/headshots/${artist} Headshot.jpg`}
alt='artist-headshot'
/>
</div>
<div className={classes.artistCardName}>
{`${node.firstName} ${node.lastName}`.toUpperCase()}
</div>
<div className={classes.artistCardText}>{node.city}</div>
<div className={classes.artistCardText}>
{node.currentTeam}
</div>
</div>
)
})}
</div>
</article>
</section>
)
}
export default ArtistsPage
My image files are set up as:
FirstName LastName Headshots.jpg
I think your issue may comes from the white spaces in the naming. Your code looks good at first sight so try renaming your images with underscore or in camelCase:
<img
src={`../../images/artists/headshots/${artist}_Headshot.jpg`}
alt='artist-headshot'
/>
After much research and the nice people on Gatsby discord I found the answer to be… in a scenario like this I needed to add require().default.
Ex:
<img
src={require(../../images/artists/headshots/${artist} Headshot.jpg).default}
alt='artist-headshot'
/>
I am getting Cannot read property 'map' of undefined when using getStaticProps in next.js inside components/featured-posts.js but if i use it directly on pages/index.js page it shows the results, anybody know why its doing this?
export async function getStaticProps(){
const data = await fetch('http://localhost/newblog/newblogapi/posts')
const posts=await data.json();
return {
props: { posts }, // will be passed to the page component as props
}
}
const FeaturedPosts = ({posts}) => {
console.log(posts)
return (
<div className="album py-5 bg-light">
<div className="container mt-5">
{ posts.map(post=>(
<div key={post.id}>
<h3>{post.title}</h3>
</div>
))}
</div>
</div>
);
}
export default FeaturedPosts;
You can only use getStaticProps on pages (files in the /pages directory), not in regular React components. I suggest you get the posts in your pages/index.js file and pass them as props to the FeaturedPosts component.
I have this Gatsby app where when I visit home page everything loads at first including the Testimonials section. However, when I visit another page, for instance the Blog list page and then click on the link back to homepage the data on Testimonials component won't load and you will see a blank area of the app where the Testimonials section is placed. In order to see the Testimonials list, you will have the refresh the page again.
For the record the data on my Testimonials component are being pulled out on Strapi JS that is deployed on Heroku.
So far I got this on my index.js:
import React from "react"
import { graphql } from "gatsby"
import Layout from "../components/Layout"
import Header from "../components/Header"
import Testimonials from '../components/Testimonials'
import Blogs from '../components/Blogs'
import SEO from '../components/SEO'
export default function Home({ data }) {
const {
allStrapiBlogs: { nodes:blogs },
} = data
return (
<>
<SEO />
<div className="main-container">
<Layout>
<Header />
<Testimonials title="Testimonials" />
<Blogs title="Latest Blogs" blogs={blogs} showAllBlogLinks/>
<Map />
</Layout>
</div>
</>
)
}
export const query = graphql`
{
allStrapiBlogs(filter: {featured: {eq: true}}, sort: {fields: published_date, order: DESC}, limit: 6) {
nodes {
id
title
content
slug
published_date(formatString: "MMMM DD, YYYY")
featured_image {
childImageSharp {
fluid {
...GatsbyImageSharpFluid
}
}
}
}
}
}
`
And then on my Testimonials.js component:
import React from "react"
import { graphql, useStaticQuery } from "gatsby"
import Image from "gatsby-image"
import { FaStar } from "react-icons/fa"
import Title from './Title'
const query = graphql`
{
allStrapiTestimonials {
nodes {
id
name
cite
text
photo {
childImageSharp {
fluid{
...GatsbyImageSharpFluid_withWebp
}
}
}
}
}
}
`
const Testimonials = ({ title }) => {
const data = useStaticQuery(query)
const { allStrapiTestimonials: { nodes:testimonials } } = data
return (
<div className="testimonial-section section-padding" id="testimonial" data-aos="zoom-in">
<div className="container">
<div className="row">
<div className="col-lg-12">
<div className="section-title-two center">
<Title title={title} />
</div>
</div>
</div>
<div className="testimonial-wrap row">
<div className="testimonial-slider owl-carousel">
{ testimonials.map(item => {
const { id, name, cite, text, photo } = item
return(
<div className="col-xl-8 col-lg-10 col-12 ml-auto mr-auto" key={id}>
<div className="testimonial-item mt-40">
<div className="testimonial_img">
<Image fluid={photo.childImageSharp.fluid} alt={name} style={{ position: "absolute", overflow: "visible", display: "block", width: "211px", height: "207px" }} />
</div>
<div className="testimonial_content xs-mt-40">
<div className="testimonial_content_item mb-30">
<div className="testimonial_content__pro">
<h4 className="mb-10">{ name }</h4>
<p>{ cite }</p>
</div>
<ul className="d-none d-sm-inline-block">
<li><FaStar></FaStar></li>
<li><FaStar></FaStar></li>
<li><FaStar></FaStar></li>
<li><FaStar></FaStar></li>
<li><FaStar></FaStar></li>
</ul>
</div>
<div>
<p>{ text } </p>
</div>
</div>
</div>
</div>
)
})}
</div>
</div>
</div>
</div>
)
}
export default Testimonials
Any idea what's causing this error? How can I fix it?
I've faced a similar issue a few months ago and the fix depends strictly on the implementation and your code. Basically, what is happening is that React's doesn't understand that he needs to rehydrate some components because pointing to some global objects as window or document of the DOM, outside the React's ecosystem (without using states) may block that rehydration, in your cause, because of jQuery.
All the possible solutions that bypass this issue will be patches (like trying to add the cache). The ideal solution would avoid using jQuery, which points directly to the DOM, with React, which manipulates the virtual DOM (vDOM).
There's nothing wrong with the code you've shared, however, based on some other questions that you did, you are using jQuery and using the window object, which prevents the rehydration of some React components. You should get rid of jQuery or using some React-based approach. Something like this should do the trick to force a loader across the whole site:
const Layout = ({ children }) => {
const [loader, setLoader]=useState(true);
useEffect(()=>{
setTimeout(()=> {
setLoader(false)
}, 400)
}, [])
return <section className={`site__wrapper`}>
<Header />
<main>{loader ? <Preloader/> : children}</main>
</section>;
};