| function(callback) { | |
| if (someCond) return void callback(); | |
| // do things | |
| return "some value"; | |
| } |
| { | |
| "name": "Ashe's Pokedex", | |
| "sort": "byName", | |
| "order": "descending", | |
| "pokemon": [ | |
| { | |
| "id": 4, | |
| "name": "Charmander", | |
| "types": "fire", | |
| "species": "lizard", |
| // === Arrays | |
| var [a, b] = [1, 2]; | |
| console.log(a, b); | |
| //=> 1 2 | |
| // Use from functions, only select from pattern | |
| var foo = () => { | |
| return [1, 2, 3]; |
| // some pieces of this file have been omitted | |
| let React = require('react') | |
| let notesStore = require('../../stores/notesStore') | |
| let monitorMixin = require('../../mixins/monitorMixin') | |
| let Notes = React.createClass({ | |
| mixins: [monitorMixin(notesStore)] | |
| // this gets called whenever `notesStore` emits a change event |
| let validActions = { | |
| [GameConstants.GAME_CREATE]: null, | |
| [GameConstants.GAME_JOIN]: null, | |
| [GameConstants.GAME_EXIT]: null, | |
| [GameConstants.USER_JOINED]: null, | |
| [GameConstants.USER_LEFT]: null | |
| } | |
| GameDispatcher.register( ({actionType, data}) => { | |
| if (actionType in validActions) { |
| /** | |
| * Ref $elector Mixin | |
| */ | |
| export default { | |
| $(ref) { | |
| return this.refs[ref].getDOMNode() | |
| } | |
| } |
| /** | |
| * Somewhere in an app module, pull in the app specific translator | |
| */ | |
| import t from 'util/translate' | |
| t("Edu_bs") | |
| // => "Bachelor's" |
| javascript:(function(){function t(){this.types={}}function e(t,e){this.el=t,this.registry=e,this.init()}t.prototype={register:function(t){var e=t.type;this.types[e]=this.types[e]||[],this.types[e].push(t)},createNavigation:function(){var t=document.createElement("div");t.className="table-of-contents clearfix";var e=document.createElement("div");e.className="btn-group right",i.parentNode.insertBefore(t,i.nextSibling),t.appendChild(e),Object.keys(this.types).forEach(function(t){var i=!0,n=document.createElement("button");n.textContent=t,n.className="btn btn-sm selected",e.appendChild(n),n.addEventListener("click",function(e){i=!i,n.classList.toggle("selected",i),this.types[t].forEach(function(t){t.toggle(i)},this),e.preventDefault()}.bind(this))},this)}},e.prototype={init:function(){this.visible=!0,this.cacheElements(),this.addToggleButton(),this.bindEvents(),this.registerType()},cacheElements:function(){this.header=this.el.querySelector(".file-header"),this.actions=this.el.querySelector(".file-actions"),this.c |
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.
elem.offsetLeft, elem.offsetTop, elem.offsetWidth, elem.offsetHeight, elem.offsetParentelem.clientLeft, elem.clientTop, elem.clientWidth, elem.clientHeightelem.getClientRects(), elem.getBoundingClientRect()