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
| 100+ different js counter apps... |
| { | |
| "version": "0.2.0", | |
| "configurations": [ | |
| { | |
| "name": "Example", | |
| "type": "node", | |
| "request": "launch", | |
| "runtimeExecutable": "node", | |
| "runtimeArgs": ["--nolazy", "-r", "ts-node/register/transpile-only"], |
| // === Arrays | |
| var [a, b] = [1, 2]; | |
| console.log(a, b); | |
| //=> 1 2 | |
| // Use from functions, only select from pattern | |
| var foo = () => [1, 2, 3]; |
| { | |
| "USD": { | |
| "symbol": "$", | |
| "name": "US Dollar", | |
| "symbol_native": "$", | |
| "decimal_digits": 2, | |
| "rounding": 0, | |
| "code": "USD", | |
| "name_plural": "US dollars" | |
| }, |
| // app/routes/api/auth/$.ts | |
| import NextAuth from "~/lib/next-auth/index.server"; | |
| export const { action, loader } = NextAuth({ | |
| providers: [ | |
| GoogleProvider({ | |
| clientId: env.GOOGLE_CLIENT_ID, | |
| clientSecret: env.GOOGLE_CLIENT_SECRET, | |
| }), | |
| ], |
| var RecursiveChildComponent = React.createClass({ | |
| render() { | |
| return <div> | |
| {this.recursiveCloneChildren(this.props.children)} | |
| </div> | |
| }, | |
| recursiveCloneChildren(children) { | |
| return React.Children.map(children, child => { | |
| if(!_.isObject(child)) return child; | |
| var childProps = {someNew: "propToAdd"}; |
npm users sorted by the monthly downloads of their modules, for the range May 6, 2018 until Jun 6, 2018.
Metrics are calculated using top-npm-users.
| # | User | Downloads |
|---|
| // set-up a connection between the client and the server | |
| var socket = io.connect(); | |
| // let's assume that the client page, once rendered, knows what room it wants to join | |
| var room = "abc123"; | |
| socket.on('connect', function() { | |
| // Connected, let's sign-up for to receive messages for this room | |
| socket.emit('room', room); | |
| }); |
I heard some points of criticism to how React deals with reactivity and it's focus on "purity". It's interesting because there are really two approaches evolving. There's a mutable + change tracking approach and there's an immutability + referential equality testing approach. It's difficult to mix and match them when you build new features on top. So that's why React has been pushing a bit harder on immutability lately to be able to build on top of it. Both have various tradeoffs but others are doing good research in other areas, so we've decided to focus on this direction and see where it leads us.
I did want to address a few points that I didn't see get enough consideration around the tradeoffs. So here's a small brain dump.
"Compiled output results in smaller apps" - E.g. Svelte apps start smaller but the compiler output is 3-4x larger per component than the equivalent VDOM approach. This is mostly due to the code that is usually shared in the VDOM "VM" needs to be inlined into each component. The tr
