Radoslaw Malecki radosny

The aim of this gist is to fix the following informative post about uploading via XHR.

Fixing the HTML

The first part is the HTML. First of all, you really don't need JavaScript to upload a file but you do need a proper form. Secondly, inputs in a form shouild have a name, because the name is what the server will receive: not IDs, names!

Following the fixed form part.

Flamegraphs for your node processes on OS X

This document will help you generate flamegraphs for your node processes on OS X.

You can read about the various types of flamegraphs and how they are useful
in Brendan Gregg's wonderful write up here.

By the end of this document, you should have a flamegraph for you node app to play with.

Virtual Hosts on nginx (CSC309)

When hosting our web applications, we often have one public IP address (i.e., an IP address visible to the outside world) using which we want to host multiple web apps. For example, one may wants to host three different web apps respectively for example1.com, example2.com, and example1.com/images on the same machine using a single IP address.

How can we do that? Well, the good news is Internet browsers

WebSockets - An Introduction

WebSockets is a modern HTML5 standard which makes communication between client and server a lot more simpler than ever. We are all familiar with the technology of sockets. Sockets have been fundamental to network communication for a long time but usually the communication over the browser has been restricted. The general restrictions

The server used to have a permanent listener while the client (aka browser) was not designated any fixed listener for a more long term connection. Hence, every communication was restricted to the client demanding and the server responding.
This meant that unless the client requested for a particular resource, the server was unable to push such a resource to the client.
This was detrimental since the client is then forced to check with the server at regular intervals. This meant a lot of libraries focused on optimizing asynchronous calls and identifying the response of asynchronous calls. Notably t

	import React, { Component } from 'react'
	import Subapp from './subapp/Root'

	class BigApp extends Component {
	render() {
	return (
	<div>
	<Subapp />
	<Subapp />
	<Subapp />

	import { combineReducers } from 'redux';
	import users from './reducers/users';
	import posts from './reducers/posts';

	export default function createReducer(asyncReducers) {
	return combineReducers({
	users,
	posts,
	...asyncReducers
	});

	function mapValues(obj, fn) {
	return Object.keys(obj).reduce((result, key) => {
	result[key] = fn(obj[key], key);
	return result;
	}, {});
	}

	function pick(obj, fn) {
	return Object.keys(obj).reduce((result, key) => {
	if (fn(obj[key])) {