React.isValidElement
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!
![Detect DOM Node Insertions with JavaScript and CSS Animations]()
I work with an awesome cast of developers at Mozilla, and one of them in Daniel Buchner. Daniel's shared with me an awesome strategy for detecting when nodes have been injected into a parent node without using the deprecated DOM Events API.
![6 Things You Didn’t Know About Firefox OS]()
Firefox OS is all over the tech news and for good reason: Mozilla's finally given web developers the platform that they need to create apps the way they've been creating them for years -- with CSS, HTML, and JavaScript. Firefox OS has been rapidly improving...
![MooTools Kwicks Plugin]()
I wrote a post titled Get Slick with MooTools Kwicks ages ago. The post was quite popular and the effect has been used often. Looking back now, the original code doesn't look as clean as it could. I've revised the original...
![Style Textarea Resizers]()
Modern browsers are nice in that they allow you to style some odd properties. Heck, one of the most popular posts on this blog is HTML5 Placeholder Styling with CSS, a tiny but useful task. Did you know you can also restyle the textarea resizer in WebKit...