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!
![fetch API]()
One of the worst kept secrets about AJAX on the web is that the underlying API for it, XMLHttpRequest, wasn't really made for what we've been using it for. We've done well to create elegant APIs around XHR but we know we can do better. Our effort to...
![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.
![Firefox Marketplace Animated Buttons]()
The Firefox Marketplace is an incredibly attractive, easy to use hub that promises to make finding and promoting awesome HTML5-powered web applications easy and convenient. While I don't work directly on the Marketplace, I am privy to the codebase (and so...
![MooTools OpenLinks Class – Updated]()
A long time back I coded a MooTools class called OpenLinks. The class is quite useful but the code...sucks. I've gotten much better with MooTools over the past years so I thought I'd go back and update the class to be better, faster...