TomaszWaszczyk

How to Eyeball Your ‘This’ Context in Javascript

The early programmer struggles with the Javascript keyword this. But understanding your this context is easier than it seems.

This is all about where a function is invoked. Often, early programmers worry about where the function was declared. Perhaps the function was declared in a specific file or a particular object. Surely this changes it's this!

Nope.

To understand this, we need to see where it is invoked. Nothing else matters, with one exception which we'll cover in a moment.

TomaszWaszczyk

Shallow

Real unit test (isolation, no children render)

Simple shallow

Calls:

• constructor
• render

TomaszWaszczyk

The purpose of this document is to make recommendations on how to browse in a privacy and security conscious manner. This information is compiled from a number of sources, which are referenced throughout the document, as well as my own experiences with the described technologies.

I welcome contributions and comments on the information contained. Please see the How to Contribute section for information on contributing your own knowledge.

Table of Contents

• Motivation
• Audience
• TL;DR?
• Updates
• Technologies that Affect Security and Privacy

TomaszWaszczyk

#!/bin/bash

get_latest_release () {
  curl --silent "https://api.github.com/repos/paritytech/polkadot/releases/latest" | # Get latest release from GitHub api
    grep '"tag_name":' |                                            # Get tag line
    sed -E 's/.*"([^"]+)".*/\1/'                                    # Pluck JSON value
}

V=`get_latest_release`
SERVICE="polkadot-validator"

TomaszWaszczyk

These original sources are now no longer available:
- http://www.xent.com/FoRK-archive/oct00/0429.html
- http://www.cryptorights.org/events/2000/superpolynomial.html

For a 2000 example of how to use this song in a lecture format, see http://permalink.gmane.org/gmane.comp.encryption.general/4856 by Eric Hughes.

To the tune of Mary Poppins:

Superpolynomial subexponential runtimes.
Even though in practice it would take you several lifetimes,

TomaszWaszczyk

var { ApiPromise, WsProvider } = require('@polkadot/api');
var { BN_ZERO } = require('@polkadot/util');

async function main() {
	const provider = new WsProvider("wss://kusama-rpc.polkadot.io/", false);
	provider.connect();
	const api = await ApiPromise.create({ provider });

	// Get general information about the node we are connected to
	const [chain, nodeName, nodeVersion] = await Promise.all([

TomaszWaszczyk

#![feature(prelude_import)]
#![no_std]
// Copyright 2017-2019 Parity Technologies (UK) Ltd.
// This file is part of Substrate.

// Substrate is free software: you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.

TomaszWaszczyk

Installing Node.js with nvm to Linux & macOS & WSL

A quick guide on how to setup Node.js development environment.

Install nvm for managing Node.js versions

nvm allows installing several versions of Node.js to the same system. Sometimes applications require a certain versions of Node.js to work. Having the flexibility of using specific versions can help.

1. Open new Terminal window.

TomaszWaszczyk

// USAGE EXAMPLE

render() {
    const { currentUserState, nearEnv } = this.state;

    return currentUserState.match({
        notAsked: () => <HomePage />,
        loading: () => <HomePage />,
        failure: (err) => <>Error occurred</>,
        success: (user) => <AppRouter currentUser={user} nearEnv={nearEnv} />,

TomaszWaszczyk

# Luke's config for the Zoomer Shell

# Enable colors and change prompt:
autoload -U colors && colors
PS1="%B%{$fg[red]%}[%{$fg[yellow]%}%n%{$fg[green]%}@%{$fg[blue]%}%M %{$fg[magenta]%}%~%{$fg[red]%}]%{$reset_color%}$%b "

# History in cache directory:
HISTSIZE=10000
SAVEHIST=10000
HISTFILE=~/.cache/zsh/history