There are a few issues in your code.
- You don't have any state to keep track of the added users
- On a form submit instead of updating the data you're trying to directly update the DOM with submitted data. Which is not the right way to do things in react.
<!-- begin snippet: js hide: false console: true babel: true -->
<!-- language: lang-js -->
import React, { useState, useEffect } from "react";
export default function App() {
const [user, setUser] = useState({
name: "",
old: ""
});
// A new state to keep track of the added users
const [users, setUsers] = useState([]);
const changeUser = e => {
const v = e.target.value;
setUser({
...user,
[e.target.name]: v
});
};
// On form submit, all you need to do is to update the users state
// Then render will take care of the rest
const submitForm = e => {
e.preventDefault();
setUsers([...users, user]);
};
// This is how in react we update the content
// Whenever, there is a change in state, this will get called and content will be updated
// Ps: It's being called in the render
const renderBody = () => {
const content = [];
users.map(item => {
content.push(
<tr>
<td>{item.name}</td>
<td>{item.old}</td>
<td>Delete btn</td>
<td>Delete btn</td>
</tr>
);
});
return content;
};
return (
<div className="to-do">
<form action="" onSubmit={submitForm}>
<label htmlFor="">
Name
<input
name="name"
onChange={changeUser}
value={user.name}
type="text"
/>
</label>
<label htmlFor="yes">
Old Yes
<input
id="yes"
name="old"
onChange={changeUser}
value="yes"
type="radio"
/>
</label>
<label htmlFor="no">
Old No
<input
id="no"
name="old"
onChange={changeUser}
value="no"
type="radio"
/>
</label>
<input value={user.old} type="submit" value="SUBMIT" />
</form>
<div className="res">
<table>
<tr>
<th>Name</th>
<th>OLD</th>
<th>DELETE</th>
<th>Edit</th>
</tr>
<tr id="res" />
{renderBody()}
</table>
</div>
</div>
);
}
<!-- language: lang-html -->
<script src="https://cdnjs.cloudflare.com/ajax/libs/react/16.6.3/umd/react.production.min.js"></script>
<script src="https://cdnjs.cloudflare.com/ajax/libs/react-dom/16.6.3/umd/react-dom.production.min.js"></script>
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So what you need
- State for users to keep track of the added users
- On form submit, a trigger to update that users state
- A loop, to iterate over users array and return table rows with content
That's [*property spread notation*][1]. It was added in ES2018 (spread for arrays/iterables was earlier, ES2015), but it's been supported in React projects for along time via transpilation (as "[JSX spread attributes][2]" even though you could do it elsewhere, too, not just attributes).
`{...this.props}` *spreads out* the "own" enumerable properties in `props` as discrete properties on the `Modal` element you're creating. For instance, if `this.props` contained `a: 1` and `b: 2`, then
<Modal {...this.props} title='Modal heading' animation={false}>
would be the same as
<Modal a={this.props.a} b={this.props.b} title='Modal heading' animation={false}>
But it's dynamic, so whatever "own" properties are in `props` are included.
Since `children` is an "own" property in `props`, spread will include it. So if the component where this appears had child elements, they'll be passed on to `Modal`. Putting child elements between the opening tag and closing tags is just syntactic sugar — the good kind — for putting a `children` property in the opening tag. Example:
<!-- begin snippet: js hide: true console: true babel: true -->
<!-- language: lang-js -->
class Example extends React.Component {
render() {
const { className, children } = this.props;
return (
<div className={className}>
{children}
</div>
);
}
}
ReactDOM.render(
[
<Example className="first">
<span>Child in first</span>
</Example>,
<Example className="second" children={<span>Child in second</span>} />
],
document.getElementById("root")
);
<!-- language: lang-css -->
.first {
color: green;
}
.second {
color: blue;
}
<!-- language: lang-html -->
<div id="root"></div>
<script src="https://cdnjs.cloudflare.com/ajax/libs/react/16.6.3/umd/react.production.min.js"></script>
<script src="https://cdnjs.cloudflare.com/ajax/libs/react-dom/16.6.3/umd/react-dom.production.min.js"></script>
<!-- end snippet -->
Spread notation is handy not only for that use case, but for creating a new object with most (or all) of the properties of an existing object — which comes up a lot when you're updating state, since you can't modify state directly:
this.setState(prevState => {
return {foo: {...prevState.foo, a: "updated"}};
});
That replaces `this.state.foo` with a new object with all the same properties as `foo` except the `a` property, which becomes `"updated"`:
<!-- begin snippet: js hide: true console: true babel: false -->
<!-- language: lang-js -->
const obj = {
foo: {
a: 1,
b: 2,
c: 3
}
};
console.log("original", obj.foo);
// Creates a NEW object and assigns it to `obj.foo`
obj.foo = {...obj.foo, a: "updated"};
console.log("updated", obj.foo);
<!-- language: lang-css -->
.as-console-wrapper {
max-height: 100% !important;
}
<!-- end snippet -->
[1]: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Operators/Spread_syntax
[2]: https://reactjs.org/docs/jsx-in-depth.html#spread-attributes
