Play! Framework 2 – Dealing with Content

A web application always has, at some point, the need to deal with multiple types of content. Common content types include JSON, XML, HTML, but there could also be images or even videos to be stored and streamed. Play! 2 provides a clean way of dealing with such content types with the help of body parsers.

We won't cover the implementation details of such body parsers, because it's purely based on a functional concept, Iteratee, and thus their implementations are in Scala only. However, we'll see how they are used and how we can gain benefits from them.

In this article by Andy Petrella author of Learning Play! Framework 2, we'll update and clean up a bit of what we have been doing so far in order to enable several workflows. So we will only be using examples we have learned up to now. The following is what will be achieved:

• Make the Chat and Item classes persistent using Ebean

• Create a link between an item and a user (a user's reply in a chat)

• Introduce a new type, Image, that will be part of a chat as an attachment

• Enable a user to connect

• Browse all chat instances

• Allow the connected user to reply in a chat

• Allow the connected user to attach an image to a chat

• Show examples of UIs

• Create an action that outputs a requested image

• Create an action that provides an Atom feed of all chats which have specific users getting involved (kind of like following)

Building a bar graph cityscape

This article by Ken Lim, author of Instant Rainmeter Desktop Customization Tool How-to, explains the method of customizing your Windows desktop wallpaper with a live cityscape for different CPU processes. The article, will guide you through the ways to customize your Windows desktop wallpaper using Rainmeter.

Move Further with NumPy Modules

NumPy has a number of modules that have been inherited from its predecessor, Numeric. Some of these packages have a SciPy counterpart, which may have fuller functionality. The numpy.dual package contains functions that are defined both in NumPy and SciPy. The packages discussed in this article are also part of the numpy.dual package.

In this article by Ivan Idris from the book NumPy Beginner’s Guide - Second Edition, we shall cover the following topics:

• The linalg package
• The fft package
• Random numbers
• Continuous and discrete distributions

What is OpenLayers?

In this article by Alessio Di Lorenzo and Giovanni Allegri, the authors of the book Instant OpenLayers Starter, we will discuss some basic points about OpenLayers

OpenLayers is an open source map viewing library, originally developed and released by MetaCarta under a BSD license. It is written in pure JavaScript and makes it easy to incorporate interactive maps from a variety of sources into your web pages and applications.