codepo8

"7 Developer Tools secrets that shouldn't be secrets" resources

Slides

• The Slides

Console

• Console Filtering
• Console overview

rauschma

Cheat sheet: classes in JavaScript

Basic members of classes

class OtherClass {}

class MyClass1 extends OtherClass {

  publicInstanceField = 1;

jkrems

JavaScript File Format Differences

There's the pervarsive notion that all JS is created equal and that there's only minor and easily detectable differences between the various file formats used to author JavaScript. This is correct, from a certain point of view.

For many people writing JavaScript that gets passed into build tools,

jaytaylor

React: Unexpected use of 'location';

Solution: Use window.location instead of bare location.

jamiewilson

CSS :focus Selector

The :focus selector is used to select the element that has focus. It is allowed on elements that accept keyboard events or other user inputs.

• HTMLInputElement
• HTMLSelectElement
• HTMLTextAreaElement
• HTMLAnchorElement
• HTMLButtonElement
• HTMLAreaElement

paulirish

What forces layout / reflow

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.

Element APIs

Getting box metrics

• elem.offsetLeft, elem.offsetTop, elem.offsetWidth, elem.offsetHeight, elem.offsetParent

cben

ufocoder

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