React shows unfinished elements before the page renders completely - reactjs

Question

I am making a posts project with React. Whenever My home page just consists a bunch of posts in cards view. If I click on a certain card, it should navigate me to that post with some details. However, before the page renders completely, I still see some lines or 'unfinished' elements so to speak.
This is what I see before the post and it's description render completely
How can I fix this?
Here is my JS file with posts:
import React, { Component } from 'react'
import { Card } from "react-bootstrap";
import { Link } from "react-router-dom";
import './Posts.css'
export class Posts extends Component {
render() {
return (
<div>
{this.props.posts.map(post => (
<Link to={`/post/${post._id}`} key={post._id}>
<Card key={post._id} className="shadow-sm">
<Card.Img variant="top" src={post.image} />
<Card.Body>
<Card.Title id="cardtitle">{post.title}</Card.Title>
</Card.Body>
</Card>
</Link>
))}
</div>
)
}
}
And here is the Post detail:
import React, { useState, useEffect } from 'react'
import axios from "axios";
import { Media } from "react-bootstrap";
import './Post.css'
function Post({ match }) {
const [post, setPost] = useState({});
useEffect(() => {
const fetchPost = async () => {
const res = await axios.get(`${POST_URL}${match.params.id}`);
setPost(res.data);
}
fetchPost();
// eslint-disable-next-line react-hooks/exhaustive-deps
}, []);
const POST_URL = `/api/v1/posts/`;
return (
<Media>
<img className="align-self-center mr-3 postImage" src={post.image} alt={post.title} />
<Media.Body>
<h5 className="postTitle text-center">{post.title}</h5>
<p>{post.description}</p>
</Media.Body>
</Media>
)
}
export default Post

Answer 1

You can create a function inside your component that conditionally render if the data has returned from the API. Something like this:
import React, { useState, useEffect } from 'react'
import axios from "axios";
import { Media } from "react-bootstrap";
import './Post.css'
function Post({ match }) {
const [post, setPost] = useState();
useEffect(() => {
const fetchPost = async () => {
const res = await axios.get(`${POST_URL}${match.params.id}`);
setPost(res.data);
}
fetchPost();
// eslint-disable-next-line react-hooks/exhaustive-deps
}, []);
const POST_URL = `/api/v1/posts/`;
const renderPost = () => {
if (post) {
return(
<Media>
<img className="align-self-center mr-3 postImage" src={post.image} alt={post.title} />
<Media.Body>
<h5 className="postTitle text-center">{post.title}</h5>
<p>{post.description}</p>
</Media.Body>
</Media>
);
}
return <h1>Loading</h1>;
}
return (
renderPost();
)
}
export default Post
I recommend you to render a spinner or a placeholder to improve the user experience while the data is loading.