Jim Ing psiborg

ReactJS Component Cheatsheet

To create a ReactComponent:

ReactComponent React.createClass(object proto)

Basic JSX example:

var TitleComponent = React.createClass({

// REQUIRED

Get the current Unix timestamp (seconds from 1970-01-01T00:00:00Z) in SQL.

MySQL: UNIX_TIMESTAMP()
PostgreSQL: CAST(EXTRACT(epoch FROM NOW()) AS INT)
MS SQL: DATEDIFF(s, '1970-01-01', GETUTCDATE())
Oracle: (CAST(SYS_EXTRACT_UTC(SYSTIMESTAMP) AS DATE) - DATE'1970-01-01') * 86400

ffmpeg

Converting Audio into Different Formats / Sample Rates

Minimal example: transcode from MP3 to WMA:
ffmpeg -i input.mp3 output.wma

You can get the list of supported formats with:
ffmpeg -formats

You can get the list of installed codecs with:

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

Bridging Native & React for iOS & Android

js -> native

native -> js

Free O'Reilly books and convenient script to just download them.

Thanks /u/FallenAege/ and /u/ShPavel/ from this Reddit post

How to use:

Take the download.sh file and put it into a directory where you want the files to be saved.
cd into the directory and make sure that it has executable permissions (chmod +x download.sh should do it)
Run ./download.sh and wee there it goes. Also if you do not want all the files, just simply comment the ones you do not want.

Electron apps

Slide deck frameworks supporting Markdown source

	var HashTable = function() {
	this._storage = [];
	this._count = 0;
	this._limit = 8;
	}


	HashTable.prototype.insert = function(key, value) {
	//create an index for our storage location by passing it through our hashing function
	var index = this.hashFunc(key, this._limit);

	/* bling.js */
	window.$ = document.querySelector.bind(document);
	window.$$ = document.querySelectorAll.bind(document);
	Node.prototype.on = window.on = function(name, fn) { this.addEventListener(name, fn); };
	NodeList.prototype.__proto__ = Array.prototype;
	NodeList.prototype.on = function(name, fn) { this.forEach((elem) => elem.on(name, fn)); };


	if ('serviceWorker' in navigator && !this.hasOwnProperty('ServiceWorkerGlobalScope')) {
	var ownUrl = new URL(document.currentScript.src);


	// Before the worker inits, keep tileserver URLs temporarily here
	var oldTileLayerProto = L.extend({}, L.TileLayer.prototype);

	L.TileLayer._urlsToWatch = [];
	L.TileLayer.prototype.initialize = function(url, options) {