Object.freeze: Immutable Objects
One of my favorite part of JavaScript has always been mutability of objects. I loved that MooTools and likewise frameworks could modify native prototypes to enhance them with functionality we knew the language need; in fact, I credit MooTools with pushing the web forward.
There are cases, however, where you don't want an object to be modifiable; you don't want values for existing properties to be changed, added, or removed. That's where Object.freeze can help -- with Object.freeze you can create immutable objects you can trust!
const obj = Object.freeze({
x: 1,
y: 2
});
// None of these do anything
obj.x = 8; // { x: 1, y: 2}
delete obj.x; // { x: 1, y: 2}
obj.z = 3; // { x: 1, y: 2}
Object.freeze is a welcomed addition to JavaScript and a necessary one. If you have objects whose integrity you want to secure, immutability is required. Object.seal provides similar functionality without the ability to freeze values, so Object.freeze is your best choice when you want to lock down an object!
![Facebook Open Graph META Tags]()
It's no secret that Facebook has become a major traffic driver for all types of websites. Nowadays even large corporations steer consumers toward their Facebook pages instead of the corporate websites directly. And of course there are Facebook "Like" and "Recommend" widgets on every website. One...
![CSS Filters]()
CSS filter support recently landed within WebKit nightlies. CSS filters provide a method for modifying the rendering of a basic DOM element, image, or video. CSS filters allow for blurring, warping, and modifying the color intensity of elements. Let's have...
![Create a Twitter AJAX Button with MooTools, jQuery, or Dojo]()
There's nothing like a subtle, slick website widget that effectively uses CSS and JavaScript to enhance the user experience. Of course widgets like that take many hours to perfect, but it doesn't take long for that effort to be rewarded with above-average user retention and...
![Element Position Swapping Using MooTools 1.2]()
We all know that MooTools 1.2 can do some pretty awesome animations. What if we want to quickly make two element swap positions without a lot of fuss? Now you can by implementing a MooTools swap() method.
MooTools 1.2 Implementation
MooTools 1.2 Usage
To call the swap...
It’s good to remind that
Object.freezedoes only shallow freeze.That’s a nice feature. Much needed. However, I hope the browser support is good.
Should I remind that MooTools’ practice to extend native prototypes prevented W3C to use well-known names like
containsandflatten, because it would have literally broken the web?Extending native prototypes is the last thing you’d want in a general purpose library.