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 Ways that CSS and JavaScript Interact That You May Not Know About

    CSS and JavaScript:  the lines seemingly get blurred by each browser release.  They have always done a very different job but in the end they are both front-end technologies so they need do need to work closely.  We have our .js files and our .css, but...

  • By
    Regular Expressions for the Rest of Us

    Sooner or later you'll run across a regular expression. With their cryptic syntax, confusing documentation and massive learning curve, most developers settle for copying and pasting them from StackOverflow and hoping they work. But what if you could decode regular expressions and harness their power? In...

Incredible Demos

  • By
    Duplicate DeSandro’s CSS Effect

    I recently stumbled upon David DeSandro's website when I saw a tweet stating that someone had stolen/hotlinked his website design and code, and he decided to do the only logical thing to retaliate:  use some simple JavaScript goodness to inject unicorns into their page.

  • By
    Comment Preview Using MooTools

    Comment previewing is an awesome addition to any blog. I've seen really simple comment previewing and some really complex comment previewing. The following is a tutorial on creating very basic comment previewing using MooTools. The XHTML You can set up your XHTML any way you'd like.

Discussion

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