Mark Flavin psynewave

JavaScript/Front-End Developer with 10+ years of experience building scalable applications using Javascript, and HTML5/CSS3.

psynewave / rick_minimal_market_explorer.html

Created May 9, 2025 17:53

	<!DOCTYPE html>
	<html lang="en">
	<head>
	<meta charset="UTF-8" />
	<meta name="viewport" content="width=device-width, initial-scale=1.0"/>
	<title>Rick Smith – Market Explorer</title>
	<style>
	/* reset & layout */
	* { box-sizing: border-box; margin: 0; padding: 0; }
	html, body { height: 100%; font-family: –apple-system, BlinkMacSystemFont, sans-serif; }

psynewave / ricktest.html

Created May 9, 2025 17:40

	<!DOCTYPE html>
	<html lang="en">
	<head>
	<meta charset="utf-8">
	<meta name="viewport" content="width=device-width,initial-scale=1">
	<title>Market Explorer Embed</title>
	<style>
	html,body{height:100%;margin:0;padding:0;}
	#pageContainer{display:flex;flex-direction:column;height:100%;}
	#iframeWrapper{flex:1;min-height:0;position:relative;}

psynewave / GetDaysBetweenDates.js

Created February 1, 2021 18:03

	const getDaysBetweenDates = (dateStart, dateEnd) => (new Date(dateEnd) - new Date(dateStart)) / (1000 * 3600 * 24);

	getDaysBetweenDates('1/21/2020', '1/21/2021'); // 366 leap year
	getDaysBetweenDates('1/21/2019', '1/20/2020'); // 365

	getDaysBetweenDates(new Date('08/04/2020'), new Date('08/24/2020'));
	getDaysBetweenDates('08/04/2020','08/24/2020');

psynewave / arrayTake.js

Created February 1, 2021 17:50

	const take = (arr, n = 1, fromStart = true) => fromStart ? arr.slice(0, n) : n < 0 ? arr.slice(n) : arr.slice(-1 * n);
	let fruits = ['Banana', 'Orange', 'Lemon', 'Apple', 'Mango']

	take(fruits)
	take(fruits, 3)
	take(fruits, -3, false)
	take(fruits, 3, false)

psynewave / parseJWT.js

Created August 26, 2020 03:09

Decode JWT Client Side

	const b64DecodeUnicode = (str) => decodeURIComponent(Array.prototype.map.call(atob(str),(c) => "%" + ("00" + c.charCodeAt(0).toString(16)).slice(-2)).join(""));

	const parseJWT = (token) => JSON.parse(b64DecodeUnicode(token.split(".")[1].replace("-", "+").replace("_", "/")));

psynewave / unescapeHTML.js

Created August 25, 2020 19:02

Unescape escaped HTML characters.

psynewave / fetchRssConvert2JSON.js

Created August 25, 2020 18:13

Fetch RSS and Convert to JSON

	const RSS_URL = `https://cors-anywhere.herokuapp.com/https://archive.org/services/collection-rss.php?collection=podcast_jeff-regan-the-great-detec_426081250`;

	const xmlToJson = (xml) => {
	let obj = {};

	try {
	xml.hasChildNodes();
	} catch (err) {
	xml = new DOMParser().parseFromString(xml, "text/xml");
	}

psynewave / checkIfObjectIsEmpty.js

Created August 25, 2020 17:45

Check if an Object is Empty

var checkIfObjectEmpty = obj => Object.keys(obj).length === 0 && obj.constructor === Object

psynewave / PokemonFetch.js

Last active August 25, 2020 17:46

Promise All Example

	const apiURL = "https://pokeapi.co/api/v2/type/1";

	const pokemonFetch = async () => {
	const initial = await fetch(apiURL);
	const initialJson = await initial.json();

	const detailsData = initialJson.pokemon.map(async i => {
	const preFetchData = await fetch(i.pokemon.url);
	return preFetchData.json();
	})

psynewave / mergeTwoArrays.js

Created July 9, 2020 22:15

One liner for merging arrays with an optional unique flag

const mergeTwoArrays = (a, b, unique = false) => unique != true ? a.concat(b) : [...new Set([...a, ...b])];