축하합니다.
정상에 도달하셨습니다.
강의소개
삭제 기능을 구현하는 방법을 소개합니다.
강의
소스코드
import {useState} from 'react';
function Article(props){
return <article>
<h2>{props.title}</h2>
{props.body}
</article>
}
function Header(props){
return <header>
<h1><a href="/" onClick={(event)=>{
event.preventDefault();
props.onChangeMode();
}}>{props.title}</a></h1>
</header>
}
function Nav(props){
const lis = []
for(let i=0; i<props.topics.length; i++){
let t = props.topics[i];
lis.push(<li key={t.id}>
<a id={t.id} href={'/read/'+t.id} onClick={event=>{
event.preventDefault();
props.onChangeMode(Number(event.target.id));
}}>{t.title}</a>
</li>)
}
return <nav>
<ol>
{lis}
</ol>
</nav>
}
function Create(props){
return <article>
<h2>Create</h2>
<form onSubmit={event=>{
event.preventDefault();
const title = event.target.title.value;
const body = event.target.body.value;
props.onCreate(title, body);
}}>
<p><input type="text" name="title" placeholder="title"/></p>
<p><textarea name="body" placeholder="body"></textarea></p>
<p><input type="submit" value="Create"></input></p>
</form>
</article>
}
function Update(props){
const [title, setTitle] = useState(props.title);
const [body, setBody] = useState(props.body);
return <article>
<h2>Update</h2>
<form onSubmit={event=>{
event.preventDefault();
const title = event.target.title.value;
const body = event.target.body.value;
props.onUpdate(title, body);
}}>
<p><input type="text" name="title" placeholder="title" value={title} onChange={event=>{
setTitle(event.target.value);
}}/></p>
<p><textarea name="body" placeholder="body" value={body} onChange={event=>{
setBody(event.target.value);
}}></textarea></p>
<p><input type="submit" value="Update"></input></p>
</form>
</article>
}
function App() {
const [mode, setMode] = useState('WELCOME');
const [id, setId] = useState(null);
const [nextId, setNextId] = useState(4);
const [topics, setTopics] = useState([
{id:1, title:'html', body:'html is ...'},
{id:2, title:'css', body:'css is ...'},
{id:3, title:'javascript', body:'javascript is ...'}
]);
let content = null;
let contextControl = null;
if(mode === 'WELCOME'){
content = <Article title="Welcome" body="Hello, WEB"></Article>
} else if(mode === 'READ'){
let title, body = null;
for(let i=0; i<topics.length; i++){
if(topics[i].id === id){
title = topics[i].title;
body = topics[i].body;
}
}
content = <Article title={title} body={body}></Article>
contextControl = <>
<li><a href={'/update/'+id} onClick={event=>{
event.preventDefault();
setMode('UPDATE');
}}>Update</a></li>
<li><input type="button" value="Delete" onClick={()=>{
const newTopics = []
for(let i=0; i<topics.length; i++){
if(topics[i].id !== id){
newTopics.push(topics[i]);
}
}
setTopics(newTopics);
setMode('WELCOME');
}} /></li>
</>
} else if(mode === 'CREATE'){
content = <Create onCreate={(_title, _body)=>{
const newTopic = {id:nextId, title:_title, body:_body}
const newTopics = [...topics]
newTopics.push(newTopic);
setTopics(newTopics);
setMode('READ');
setId(nextId);
setNextId(nextId+1);
}}></Create>
} else if(mode === 'UPDATE'){
let title, body = null;
for(let i=0; i<topics.length; i++){
if(topics[i].id === id){
title = topics[i].title;
body = topics[i].body;
}
}
content = <Update title={title} body={body} onUpdate={(title, body)=>{
console.log(title, body);
const newTopics = [...topics]
const updatedTopic = {id:id, title:title, body:body}
for(let i=0; i<newTopics.length; i++){
if(newTopics[i].id === id){
newTopics[i] = updatedTopic;
break;
}
}
setTopics(newTopics);
setMode('READ');
}}></Update>
}
return (
<div>
<Header title="WEB" onChangeMode={()=>{
setMode('WELCOME');
}}></Header>
<Nav topics={topics} onChangeMode={(_id)=>{
setMode('READ');
setId(_id);
}}></Nav>
{content}
<ul>
<li><a href="/create" onClick={event=>{
event.preventDefault();
setMode('CREATE');
}}>Create</a></li>
{contextControl}
</ul>
</div>
);
}
export default App;
라이브 데모
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