I'd like to unmount a single react component, which belongs to a parent component containing three components total. The parent component has this render function:
render: function () {
return (
<div className={classes}>
<Navbar ref="navbar"/>
<Home ref="home"/>
<Footer ref="footer"/>
</div>
),
handleNavbarClick: function () {
// remove Home
}
if a user then clicks on a link in the navbar and I want to unmount the Home component, how would I do that? it seems like my only option is to do something like this (taken from react.js: removing a component), but this seems pretty gross:
render: function () {
var home = this.state.remove_home ? null : <Home ref="home />
return (
<div className={classes}>
<Navbar ref="navbar"/>
{home}
<Footer ref="footer"/>
</div>
),
handleNavbarClick: function () {
this.setState({remove_home: true});
}
Is that the appropriate react way to do things?
ReactJS componentWillUnmount() Method The componentWillUnmount() method allows us to execute the React code when the component gets destroyed or unmounted from the DOM (Document Object Model). This method is called during the Unmounting phase of the React Life-cycle i.e before the component gets unmounted.
When rendering a function component, the state change causes the component to unmount and then remount. The same component using class based implementation won't unmount.
Your components are remounting every time because you're using the component prop. Quoting from the docs: When you use component (instead of render or children , below) the router uses React. createElement to create a new React element from the given component.
The useEffect() hook is called when the component is mounted and sets the mounted. current value to true . The return function from the useEffect() hook is called when the component is unmounted and sets the mounted. current value to false .
Yes, your proposed solution of
render: function () {
var home = this.state.remove_home ? null : <Home ref="home" />
return (
<div className={classes}>
<Navbar ref="navbar"/>
{home}
<Footer ref="footer"/>
</div>
),
handleNavbarClick: function () {
this.setState({remove_home: true});
}
is more-or-less the "correct" way to handle this with React. Remember, the purpose of render
is to describe the way your component should look at any given point. Reaching out to the DOM and performing manual operations, or doing other kind of imperative work like "removing" an element, is almost always the wrong thing to do.
If you're concerned about the syntax, you can consider inlining or extracting the logic:
render: function () {
return (
<div className={classes}>
<Navbar ref="navbar"/>
{this.state.remove_home ? null : <Home ref="home" />}
<Footer ref="footer"/>
</div>
),
or
render: function () {
return (
<div className={classes}>
<Navbar ref="navbar"/>
{!this.state.remove_home && <Home ref="home" />}
<Footer ref="footer"/>
</div>
),
or
render: function () {
return (
<div className={classes}>
<Navbar ref="navbar"/>
{this.renderHome()}
<Footer ref="footer"/>
</div>
),
renderHome: function() {
if (!this.state.remove_home) {
<Home ref="home" />
}
}
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