Avraam Mavridis AvraamMavridis

This API was removed in React 17

Interaction tracing with React

React recently introduced an experimental profiler API. After discussing this API with several teams at Facebook, one common piece of feedback was that the performance information would be more useful if it could be associated with the events that caused the application to render (e.g. button click, XHR response). Tracing these events (or "interactions") would enable more powerful tooling to be built around the timing information, capable of answering questions like "What caused this really slow commit?" or "How long does it typically take for this interaction to update the DOM?".

With version 16.4.3, React added experimental support for this tracing by way of a new NPM package, scheduler. However the public API for this package is not yet finalized and will likely change with upcoming minor releases, so it should be used with caution.

3 hidden Python tips 🐍

Hidden from beginner tutorials and seldom found in books.

1. You can multiply a string to repeated it:

>>> "HOOLI-"*2
'HOOLI-HOOLI-'

A better setup for Git

Git default configuration is good but it can be personalized to improve your workflow efficiency. Here are some good lines to put in your ~/.gitconfig:

# The basics, who you commit as:
[user]
  name = John Doe
  email = [email protected]

require-from-twitter

Since Twitter doesn't have an edit button, it's a suitable host for JavaScript modules.

How to use

Source tweet: https://twitter.com/rauchg/status/712799807073419264

const leftPad = await requireFromTwitter('712799807073419264');

AWS Certification notes

Those are my personal notes on AWS Solution Architect certification preparation. Hope you find them usefull.

To pass AWS certification, you should have:

Sound knowledge about most of the AWS services ( EC2, VPC, RDS, Cloudfront, S3, Route53 etc,)
Hands on experience with AWS services.

	/**
	* Pan
	* ---
	*
	* A collection one-finger Pan gesture recognizers.
	*
	* A pan is an omnidirectional one- or two-finger gesture that expands the field of view.
	* Drag is typically used with pan.
	*
	*/

	import { Component } from 'react'
	import propOr from 'ramda/src/propOr'
	import identity from 'ramda/src/identity'
	import map from 'ramda/src/map'
	import compose from 'ramda/src/compose'

	class FluxComponent extends Component {
	static createReducer = (initialState, handlers) => (state = {}, action) =>
	propOr(identity, action.type, handlers)(state, action)

	/**
	* Invalidates the current `ServiceWorker` running on the page.
	* Why? Because managing a cache is damn hard; and sometimes due to race conditions
	* your assets might get out-of-sync.
	*
	* This mini snippet checks the version of the app against an uncached resource and
	* invalidates the workers if it finds a mismatch.
	*/

	if ( navigator.serviceWorker && navigator.serviceWorker.getRegistrations ) {

	var str = 'class ಠ_ಠ extends Array {constructor(j = "a", ...c) {const q = (({u: e}) => {return { [`s${c}`]: Symbol(j) };})({});super(j, q, ...c);}}' +
	'new Promise((f) => {const a = function* (){return "\u{20BB7}".match(/./u)[0].length === 2 \|\| true;};for (let vre of a()) {' +
	'const [uw, as, he, re] = [new Set(), new WeakSet(), new Map(), new WeakMap()];break;}f(new Proxy({}, {get: (han, h) => h in han ? han[h] ' +
	': "42".repeat(0o10)}));}).then(bi => new ಠ_ಠ(bi.rd));';

	try {
	eval(str);
	} catch(e) {
	alert('Your browser does not support ES6!')
	}

	[ {
	"Date" : "2016-07-30",
	"Data" : {
	"Moves" : [
	{ "ID" : 13, "Key" : "Power", "Old Value" : 15, "New Value" : 25 },
	{ "ID" : 14, "Key" : "Power", "Old Value" : 70, "New Value" : 120 },
	{ "ID" : 18, "Key" : "Power", "Old Value" : 25, "New Value" : 30 },
	{ "ID" : 20, "Key" : "Power", "Old Value" : 15, "New Value" : 25 },
	{ "ID" : 21, "Key" : "Power", "Old Value" : 35, "New Value" : 40 },
	{ "ID" : 22, "Key" : "Power", "Old Value" : 55, "New Value" : 80 },