Fotis Papadogeorgopoulos fpapado

Javascript Study Notes

These are my own paper version notes meeting the digital world. They are related to my learnings from 2017-18, or just stuff I thought would be nice to keep a record during the time I was grasping some Javascript topics.

PS: Don't expect all the material here to be 100% accurate or up-to-date. If you find some part that's wrong, or missing or old, please send me a comment to fix! :)

Service Worker - offline support for the web

Progressive apps - high-res icon, splash screen, no URL bar, etc.

Progressive Web Apps: Escaping Tabs Without Losing Our Soul

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

TypeScript and currying

In functional programming you often want to apply a function partly. A simple example is a function add. It would be nice if we could use add like:

var res2 = add(1, 3); // => 4

var add10To = add(10);
var res = add10To(5); // => 15

	#!/bin/bash

	# Calculate the total size of artifacts in GitHub repo (not visible in the UI).
	# Needs token with the "repo" scope: Profile > Settings > Developer Settings > Personal access tokens
	#
	# Requires jq 1.6 or higher.

	if [ $# -ne 1 ] \|\| [ -z $API_TOKEN ]; then
	echo "Usage: API_TOKEN=<token> $0 <org/repo>"
	exit 1

	/*
	----------- primitive ----------
	object non-nullable primitive nullable
	------------- {} --------------
	---------------- unknown -----------------

	https://www.oreilly.com/library/view/programming-typescript/9781492037644/ch04.html
	https://gist.github.com/OliverJAsh/381cd397008309c4a95d8f9bd31adcd7
	*/