i have a button component from material UI. What i wanna do is i click a button and it renders to me a new Button on the screen. That's what i did
const [button, setButton] = useState([]);
function addButton(){
let newObj = {
button: <Button variant="contained"> A Button</Button>,
};
setButton([...button, newObj])
}
And then in the main function return i did
{button.length !== 0 ? (
button.map((item) => {
<div>{item.button}</div>;
})
) : (
<div>Hello</div>
)}
What am i doing wrong?
When you use a multi-line lambda with braces you need a return...
button.map((item) => {
return (<div>{item.button}</div>);
})
Alternatively you can omit the braces...
button.map((item) => (<div>{item.button}</div>))
This answer tries to address the below problem-statement:
But how could i click one button and render as many buttons as i clicked?
The below snippet provides a demo of how a new button may be rendered when user clicks an existing button. This expands on the below comment
Creating a new button on clicking an existing button may be accomplished without needing to hold the component in state.
Please note:
Code Snippet
const {useState} = React;
const MyButton = ({
btnLabel, btnName, handleClick, isDisabled, ...props
}) => (
<button
class="myBtn"
onClick={handleClick}
name={btnName}
disabled={isDisabled}
>
{btnLabel}
</button>
);
const MagicButtons = () => {
const [btnText, setBtnText] = useState("");
const [disableBtns, setDisableBtns] = useState(false);
const [myButtons, setMyButtons] = useState(["A Button"]);
const handleClick = () => setDisableBtns(true);
return (
<div>
{
disableBtns && (
<div class="myInput">
<input
value={btnText}
onChange={e => setBtnText(e.target.value)}
/>
<button
onClick={() => {
setMyButtons(prev => ([...prev, btnText]));
setBtnText("");
setDisableBtns(false);
}}
>
Add New Button
</button>
</div>
)
}
{
myButtons.map((txt, idx) => (
<MyButton
handleClick={handleClick}
btnName={idx}
isDisabled={disableBtns ? "disabled" : ""}
btnLabel={txt}
/>
))
}
</div>
);
};
ReactDOM.render(
<div>
DEMO
<MagicButtons />
</div>,
document.getElementById("rd")
);.myBtn { margin: 15px; }
.myInput > input { margin: 15px; }<div id="rd" />
<script src="https://cdnjs.cloudflare.com/ajax/libs/react/16.8.0/umd/react.production.min.js"></script>
<script src="https://cdnjs.cloudflare.com/ajax/libs/react-dom/16.8.0/umd/react-dom.production.min.js"></script>You forgot to return the component in the map function like this
{button.length !== 0 ? (
button.map((item) => {
return (<div>{item.button}</div>);
})
) : (
<div>Hello</div>
)}
the map function with no 'return' keyword must not have the bracket { } like this
button.map((item) => (<div>{item.button}</div>))