Vitalii Sashyn vsashyn

(I'm enjoying doing these raw, barely edited writeups; I hope they're useful to you too)

Feature flags

This is my own writeup on feature flags; for a deep dive I'd recommend something like Martin Fowler's article (https://martinfowler.com/articles/feature-toggles.html).

So. Feature flags. The basic idea that you'll store configuration/values on a database/service somewhere, and by changing those values, you can change the user experience/features for a user on the fly.

Let's say that you're building a new feature, called 'new-button' which changes the color of buttons, which is currently red, to blue. Then you'd change code that looks like this -

Рецепты использования Webpack

Apple Pay on Web (iPhone)

Contents:

Guidelines for using Apple Pay
Setup merchant account on Apple
Create merchant session
Setup Apple Pay on customer iPhone
Extract payment token from Apple Pay response

The Revealing Module Pattern in Javascript

Zach Caceres

Javascript does not have the typical 'private' and 'public' specifiers of more traditional object oriented languages like C# or Java. However, you can achieve the same effect through the clever application of Javascript's function-level scoping. The Revealing Module pattern is a design pattern for Javascript applications that elegantly solves this problem.

The central principle of the Revealing Module pattern is that all functionality and variables should be hidden unless deliberately exposed.

Let's imagine we have a music application where a musicPlayer.js file handles much of our user's experience. We need to access some methods, but shouldn't be able to mess with other methods or variables.

Using Function Scope to Create Public and Private Methods

Debugging node running on a remote server

Node uses a TCP interface for debugging, so if you can get a handle on the right port, you can debug apps running remotely. This means you can run through code on staging, Vagrant, etc. The following shows you how to start node with the debug flag and use an SSH tunnel to access the right port.

Things you need:

ssh access to the server
ability to restart node app with --debug flag or node-inspector installed on server

Debugging using Webstorm

The introduction to Reactive Programming you've been missing

(by @andrestaltz)

This tutorial as a series of videos

If you prefer to watch video tutorials with live-coding, then check out this series I recorded with the same contents as in this article: Egghead.io - Introduction to Reactive Programming.

	/**
	* Shorthand function for document.createElement. Accepts and appends attributes to the newly created element and appends child element, if any.
	* @param tagName The name of the element eg. a or script
	* @param attributes Any additional attributes to add to the element after creating. Eg. href
	* @param children Any child elements you want appended on creating this element, obviously they could be createElement calls as well
	*/
	export function createElement(tagName, attributes, children) {
	const ele = attributes === (void 0)
	? document.createElement(tagName)
	: Object.assign(document.createElement(tagName), attributes);

	var Middleware = function() {};

	Middleware.prototype.use = function(fn) {
	var self = this;

	this.go = (function(stack) {
	return function(next) {
	stack.call(self, function() {
	fn.call(self, next.bind(self));
	});

	'use strict';

	module.exports = function CustomError(message, extra) {
	Error.captureStackTrace(this, this.constructor);
	this.name = this.constructor.name;
	this.message = message;
	this.extra = extra;
	};

	require('util').inherits(module.exports, Error);