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!
![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...
![CSS @supports]()
Feature detection via JavaScript is a client side best practice and for all the right reasons, but unfortunately that same functionality hasn't been available within CSS. What we end up doing is repeating the same properties multiple times with each browser prefix. Yuck. Another thing we...
![Printing MooTools Accordion Items]()
Sometimes we're presented with unforeseen problems when it comes to our JavaScript effects. In this case, I'm talking about printing jQuery and MooTools accordions. Each "closed" accordion content element has its height set to 0 which means it will be hidden when the...
![Create a Simple Slideshow Using MooTools, Part II: Controls and Events]()
Last week we created a very simple MooTools slideshow script. The script was very primitive: no events and no next/previous controls -- just cross-fading between images. This tutorial will take the previous slideshow script a step further by:
Adding "Next" and "Previous" controls.
Adding...