react / jsx syntax

Simple syntax question.  I found this bit of code on fullstackreact.com and I'm curious why on line 2 the constant name is in braces.  Is this common/best practice for jsx? Currently I'm not doing it, should I be? Why?

 render() {
    const {refreshing} = this.state;
    return (
      <div className='notificationsFrame'>
        <div className='panel'>
          <Header title="Github activity" />
          {/* refreshing is the component's state */}
          <Content
            onComponentRefresh={this.onComponentRefresh.bind(this)}
            requestRefresh={refreshing}
            fetchData={fetchEvents} />
          {/* A container for styling */}
          <Footer>
            <button onClick={this.refresh.bind(this)}>
              <i className="fa fa-refresh" />
              Refresh
            </button>
          </Footer>
        </div>
      </div>
    )
  }
}

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tf2012Asked:
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leakim971PluritechnicianCommented:
It's not JSX but some news from ECMAScript 6
It's a shortcut of :
var refreshing = this.state.refreshing;

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As you can see, we don't use the key word "refreshing" two times.
Is this common/best practice for jsx?
Not necessarily, just a shortcut

Currently I'm not doing it, should I be? Why?
Please note the browser compatibilty :
https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Operators/Destructuring_assignment#Browser_compatibility
So most of time you compile the code (typescript, jsx) and you get compatible javascript for moderm browser. If you're not using a compiler, be sure your target browser can run the javascript your provide to it.

More info here :
https://www.ecma-international.org/ecma-262/6.0/#sec-destructuring-assignment
https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Operators/Destructuring_assignment

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tf2012Author Commented:
thanks
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