React.isValidElement

By  on  

Knowing what input type you've received is hugely important in JavaScript, which is a big reason for Flow and TypeScript's rise. One such case where it's useful to know what an object represents is if the input is a string or a React element.

To detect if an object is a React element, you can use React.isValidElement(obj):

// Add a wrapping DIV if the content isn't a React element

// PropTypes.oneOfType([PropTypes.string, PropTypes.element])
render() {
  const { content } = this.props

  React.isValidElement(content)) ?
    content :
    
{content}
}

I really like that React.isValidElement allows us to create flexible elements that accept React elements or strings; hugely useful in generic components like modals, alerts, and everywhere else!

Recent Features

  • By
    5 HTML5 APIs You Didn’t Know Existed

    When you say or read "HTML5", you half expect exotic dancers and unicorns to walk into the room to the tune of "I'm Sexy and I Know It."  Can you blame us though?  We watched the fundamental APIs stagnate for so long that a basic feature...

  • By
    Responsive and Infinitely Scalable JS Animations

    Back in late 2012 it was not easy to find open source projects using requestAnimationFrame() - this is the hook that allows Javascript code to synchronize with a web browser's native paint loop. Animations using this method can run at 60 fps and deliver fantastic...

Incredible Demos

  • By
    Duplicate the jQuery Homepage Tooltips Using Dojo

    The jQuery homepage has a pretty suave tooltip-like effect as seen below: Here's how to accomplish this same effect using Dojo. The XHTML The above HTML was taken directly from the jQuery homepage -- no changes. The CSS The above CSS has been slightly modified to match the CSS rules already...

  • By
    AJAX For Evil:  Spyjax with jQuery

    Last year I wrote a popular post titled AJAX For Evil: Spyjax when I described a technique called "Spyjax": Spyjax, as I know it, is taking information from the user's computer for your own use — specifically their browsing habits. By using CSS and JavaScript, I...

Discussion

    Wrap your code in <pre class="{language}"></pre> tags, link to a GitHub gist, JSFiddle fiddle, or CodePen pen to embed!