Romain Sertelon rsertelon

The introduction to Reactive Programming you've been missing

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.

Is socket.push(bytes) all you need to program Realtime Web apps?

One of the goals of Play2 architecture is to provide a programming model for what is called Realtime Web Applications.

Realtime Web Applications

Realtime Web Applications are applications that make use of Websockets, Server Sent Events, Comet or other protocols offering/simulating an open socket between the browser and the server for continuous communication. Basically, these applications let users work with information as it is published - without having to periodically ping the service.

There are quite a few web frameworks that target the development of this type of application: but usually the solution is to simply provide an API that allows developers to push/receive messages from/to an open channel, something like:

If your csv doesn't contain escaped newlines then it is pretty easy to do a progressive parsing without putting the whole file into memory. The iteratee library comes with a method search inside play.api.libs.iteratee.Parsing :

def search (needle: Array[Byte]): Enumeratee[Array[Byte], MatchInfo[Array[Byte]]]

which will partition your stream into Matched[Array[Byte]] and Unmatched[Array[Byte]]

Then you can combine a first iteratee that takes a header and another that will fold into the umatched results. This should look like the following code:

// break at each match and concat unmatches and drop the last received element (the match)

	# Licence : AGPLv3+
	# rule:[Privacy]
	if anyof (
	address :is :domain "From" "gmail.com",
	address :is :domain "From" "live.com",
	address :is :domain "From" "msn.com",
	address :is :domain "From" "hotmail.com",
	address :is :domain "From" "hotmail.fr",
	address :is :domain "From" "yahoo.com",
	address :is :domain "From" "yahoo.fr"

	#!/bin/bash
	# bash generate random alphanumeric string
	#

	# bash generate random 32 character alphanumeric string (upper and lowercase) and
	NEW_UUID=$(cat /dev/urandom \| tr -dc 'a-zA-Z0-9' \| fold -w 32 \| head -n 1)

	# bash generate random 32 character alphanumeric string (lowercase only)
	cat /dev/urandom \| tr -dc 'a-z0-9' \| fold -w 32 \| head -n 1

	# --- !Ups

	CREATE TABLE users(
	email VARCHAR(255) NOT NULL PRIMARY KEY,
	name VARCHAR(255)
	);

	CREATE TABLE subjects(
	id INTEGER NOT NULL AUTO_INCREMENT PRIMARY KEY,
	title LONGTEXT NOT NULL,

	// © 2012 Viktor Klang

	import akka.dispatch.ExecutionContext
	import javax.swing.SwingUtilities
	import java.util.concurrent.Executor

	//
	object SwingExecutionContext {
	implicit val swingExecutionContext: ExecutionContext = ExecutionContext.fromExecutor(new Executor {
	def execute(command: Runnable): Unit = SwingUtilities invokeLater command

	// ©2012 Viktor Klang

	package akka.klang

	import akka.dispatch.{ DispatcherPrerequisites, ExecutorServiceFactory, ExecutorServiceConfigurator }
	import com.typesafe.config.Config
	import java.util.concurrent.{ ExecutorService, AbstractExecutorService, ThreadFactory, TimeUnit }
	import java.util.Collections
	import javax.swing.SwingUtilities

	[alias]
	standup = log --all --since yesterday --oneline --author <your_firstname>

	/*
	Copyright 2012-2021 Viktor Klang

	Licensed under the Apache License, Version 2.0 (the "License");
	you may not use this file except in compliance with the License.
	You may obtain a copy of the License at

	http://www.apache.org/licenses/LICENSE-2.0

	Unless required by applicable law or agreed to in writing, software