Wish you had some immutability in Javascript? Now you can!
var t = {a: 1, b: 2}.immutable();
console.log(t.a, t.b);
try {
t.a = 3; // -> Uncaught Error: a is immutable and cannot be modified.
} catch (e) {
console.log(e);
}
var t2 = t.copy({a: 3});
All of the below properties or methods, when requested/called in JavaScript, will trigger the browser to synchronously calculate the style and layout*. This is also called reflow or layout thrashing, and is common performance bottleneck.
Generally, all APIs that synchronously provide layout metrics will trigger forced reflow / layout. Read on for additional cases and details.
elem.offsetLeft, elem.offsetTop, elem.offsetWidth, elem.offsetHeight, elem.offsetParent| <!DOCTYPE html> | |
| <html> | |
| <head></head> | |
| <body> | |
| <script type=text/javascript> | |
| navigator.getUserMedia = navigator.getUserMedia | |
| || navigator.webkitGetUserMedia | |
| || navigator.mozGetUserMedia; |
