HTML5: Server-sent events with Angular.js, Node.js and Express.js
I was playing around with Node.js and Express.js and happened to run across an article on server-sent events. Server-sent events is a W3C specification that ...
Drag and Drop with AngularJS using jQuery UI
In the last couple of weeks I’ve started working with AngularJS. AngularJS is a great simple framework that allows you to create complete web-apps in javascr...
Tutorial: Node.js and Express.js - Part I - Getting started
A couple of months ago a wrote a series of tutorials on scalatra. In this article, and a couple of follow ups, I’ll do the same for Node.js together with Exp...
HAL 9000 Soundboard with HTML5, Canvas and HTML5 Audio
In the last month I’ve been experimenting with the Web Audio API. Currently I’m looking at how you can use this API to create robot sounds and was looking fo...
Use COLOURlovers top patterns as random background for you web application
A couple of days ago I stumbled on the COLOURlovers site from the Android Play Store. This site provides a whole lot of beautiful patterns, colors and palett...
Copy and paste images into your browser using W3C Clipboard API
Just a quick article about the Clipboard API and how you can use this to quickly add copy and paste support for your applications. The clipboard API is a bi...
Exploring the HTML5 Web Audio: visualizing sound
If you’ve read some of my other articles on this blog you probably know I’m a fan of HTML5. With HTML5 we get all this interesting functionality, directly in...
HTML5: Use the pointer lock API to restrict mouse movement to an element
In this article we’ll look a bit closer at one of the new web APIs that recently has landed in Chrome: the pointer lock API (http://www.w3.org/TR/pointerlock...
Tutorial: Getting started with scala and scalatra - Part IV
Welcome to the last part of this series of tutorials on scala and scalatra. In this part we’ll look at how you can use Akka to handle your requests using an ...
Record audio using webrtc in chrome and speech recognition with websockets
There are many different web api standards that are turning the web browser into a complete application platform. With websockets we get nice asynchronous co...
Deep dive into chrome web intents
In a previous article I already wrote about the web intents API. At that time the web intents feature was very experimental, but already usuable. In this art...
Tutorial: Getting started with scala and scalatra - Part III
This post is the third on a series of articles I’m writing on scalatra. In “part I” we created the initial environment, and in “part II” we created the first...
Access the Twitter REST API (v1.1) from Scala and Java using signpost
If you’ve read some other articles on this blog you might know that I like creating visualizations of various datasets. I’ve just started a small project whe...
Hot code replace for scala / scalatra with free JRebel
One of the (many) advantages of working with the Play framework is that you can start the server and have your changes automatically reloaded. This makes dev...
Tutorial: Getting started with scala and scalatra - Part II
In the previous part of the tutorial we created a simple application from scratch and setup Eclipse so we could edit the scala files for scalatra. In this se...
Tutorial: Getting started with scala and scalatra - Part I
In this series of tutorials we’re going to look a bit closer at scalatra. Scalatra is a lightweight scala based micro-web framework, that can be used to crea...
HTML5: Render urban population growth on a 3D world globe with Three.js and canvas
In this article I’ll once again look at data / geo visualization with Three.js. This time I’ll show you how you can plot the urban population growth over the...
HTML5: Render open data on a 3D world globe with Three.js
With Three.js it’s very easy to create 3D objects and render these using WebGL. In a couple of previous articles I already showed how you can create 3D maps ...
Remote opera debugging on android
The final article on remote debugging web applications on mobile devices shows how you can do this using Opera Mobile. With Opera Mobile you can easily debug...
Remote firefox debugging on android
In the previous article I wrote about remote debugging web applications using chrome on Android. If you don’t want to use chrome or you want to test and debu...
Remote chrome debugging on android
With the latest versions of chrome debugging web apps running on smartphones and tablets has become a lot easier. This article shows you how to setup the req...
Motion controlled space invaders using webrtc and canvas
TL;DR: Play the game here (requires current Chrome, Opera of Firefox with webrtc enabled): Motion controlled space invaders A couple of days ago I ran acros...
Euro debt and financial crisis visualized with timeline using d3.js and Three.js
n a couple of recent articles I’ve been using Three.js and d3.js to create 3D maps and visualize metrics. In the last week I combined a couple of these techn...
Three.js: render real world terrain from heightmap using open data
Three.js is a great library for creating 3D objects and animations. In a couple of previous articles I explored this library a bit and in one of those exampl...
Render geographic information in 3D with Three.js and D3.js
The last couple of days I’ve been playing around with three.js and geo information. I wanted to be able to render map/geo data (e.g. in geojson format) insid...
Create complex Word (.docx) documents programatically with docx4j
A couple of months ago I needed to create a dynamic Word document with a number of tables and paragraphs. In the past I’ve used POI for this, but I’ve found ...
HTML5 geolocation API to measure speed and heading of your car
In this article we’ll show you how you can use the W3C geolocation API to measure the speed and the heading of your car while driving. This article further u...
HTML5: Web intents to share information between web apps
If you’ve read any of my other articles you’re probably aware that I really like this whole “browser as the platform” concept. We can easily communicate with...
Compress PDF in Mac using command line (for free)
Compressing a PDF in Mac is very easy and doesn’t require any of the commercial tools out there. This isn’t an area I normally blog about, but when I needed ...
HTML5: Access Battery status through javascript
Update 19-01-2014: Well the adoption rate is very small. Firefox still supports this, but support has still not landed in Chrome (see here: https://code.goog...
Three.js tutorial: example with webgl, canvas and webworkers
In this tutorial we’ll look at how you can use three.js to render a 3D map of an image using webgl on a canvas element. In this example we’ll rasterize an im...
Adjust colors of your page based on the lighting of the room with HTML5, webrtc and a webcam
Most modern laptops automatically dim the screen when the light conditions in the room change. If there is a lot of light, the screen normally increases in b...
Stop labeling everything as an impedance mismatch!
I recently ran across an article that was talking (again) about the Object-Relational mismatch. And just like in many articles this mismatch is called the O...
HTML5: Remotely vibrate a phone with morse code using web sockets and the vibrate API.
In my last couple of blog posts I showed you can use a couple of the new HTML5 related APIs (webrtc, web workers, device orientation) directly from your brow...
HTML5: Easily parallelize jobs using web workers and a threadpool
I’ve been experimenting with web workers and the various browser implementations. Most of the articles I’ve seen show an example where a single worker thread...
Presentation: From REST to HATEOAS
Yesterday I gave a presentation at JPoint’s meetingpoint on how to get your API or service from using the basic REST principles such as verbs and resources t...
Partial image manipulation with canvas and webworkers
In my previous article I showed how to use box2d-web and deviceorientation to rol around a set of circles using standard HTML5 APIs. My initial goal of that ...
HTML5: Combining physics engine (box2dWeb) with DeviceOrientation
When the first smartphones came out, they all had the traditional labyrinth applications. Application where you had to move a ball around a certain path by t...
Access WSO2 Registry programatically
When you have many services it is a good thing to register them somewhere so your consumers can easily find them, see what they are about, determine whether ...
Using SPDY and HTTP transparently using Netty
Most people have already heard about SPDY, the protocol, from google, proposed as a replacement for the aging HTTP protocol. Webservers are browsers are slow...
Binary websockets with Play 2.0 and Scala (and a bit op JavaCV/OpenCV)
In a recent article I showed how you can use webrtc, canvas and websockets together to create a face detection application whose frontend runs completely in ...
Face detection using HTML5, javascript, webrtc, websockets, Jetty and OpenCV
Through HTML5 and the corresponding standards, modern browsers get more standarized features with every release. Most people have heard of websockets that al...
Connect to RabbitMQ (AMQP) using Scala, Play and Akka
In this article we’ll look at how you can connect from Scala to RabbitMQ so you can support the AMQP protocol from your applications. In this example I’ll us...
Election site part 1: Basics with Knockout.js, Bootstrap and d3.js
This article shows how you can use knockout.js, Twitter’s Bootstrap and d3.js together to create a javascript application that creates visually pleasing grap...
How to use SPDY with Jetty
SPDY is a new protocol proposed by Google as a new protocol for the web. SPDY is compatible with HTTP but tries to reduce web page loading by using compressi...
Protect a REST service using HMAC (Play 2.0)
When you talk about security for REST based APIs, people often point to HTTPS. With HTTPS you can easily protect your services from prying eyes using methods...
How to analyze Java SSL errors
In my recent projects I’ve had to do a lot with certificates, java and HTTPS with client-side authentication. In most of these projects, either during testin...
Play 2.0: Akka, Rest, Json and dependencies
I’ve been diving more and more into scala the last couple of months. Scala together with the “Play Framework” provides you with a very effective and quick de...
Embedded Jetty with client certificates
Every time I start with an embedded Jetty server, I can’t find any up to date documentation and have to mess around with old, obsolete and deprecated documen...
Client certificates with HTTPClient 4
I just wrote a small post on how to setup Jetty to support client-side certificates (http://www.smartjava.org/content/embedded-jetty-client-certificates). To...
How should REST services be documented?
REST has become the standard way of creating APIs and exposing resources on the internet. Traditional web services (using SOAP and various sets of WS-* stand...
Using Querulous with Scala on postgresql
I’ve started diving deeper into scala and as a language I’m starting to like it. Combine it with the Play framework and you’ve got a nice, statically typed, ...
Maven and wildcard exclusions
Once in a while I run into the problem where I don’t want to exclude a single dependency from a maven dependency, but all dependencies. For instance I recent...
Embedded Jetty, Vaadin and Weld
When I develop web applications I like to be able to quickly start them from Eclipse without having to rely on all kinds of heavy-weight tomcat or glassfish ...
Using d3.js to visualize GIS
I've been playing around with d3.js a bit the last couple of days and it's a great little javascript library to visualize information. I needed a simple li...
Mule and WSO2 Registry integration
In this two part article we’ll look at how we can use the WSO2 registry (http://wso2.com/products/governance-registry/) as the service repository for service...
First steps with Mule 3.0
Been a while since I looked at the new versions of Mule, so took some time this weekend to look at the new version of Mule. After a rather unexpected small d...