Exploring Cats Effect
In two previous articles we explored how you can use ZIO to easily create programs in a type-safe manner: Exploring ZIO - Part I Exploring ZIO - Part I...
Tags
- posts 125
- scala 37
- html5 25
- javascript 13
- three.js 13
- rest 10
- d3.js 9
- java 9
- akka 9
- docker 8
- chrome 7
- webgl 6
- websockets 5
- reactive 5
- ssl 4
- jetty 4
- play 4
- webrtc 4
- scalatra 4
- visualization 4
- snippets 4
- scalaz 4
- typescript 4
- gis 3
- canvas 3
- debugging 3
- node.js 3
- angularjs 3
- mongodb 3
- vert.x 3
- go-lang 3
- go 3
- akka-streams 3
- top 3
- consul 3
- devoxx 3
- k8s 3
- zio 3
- wso2 2
- postgresql 2
- governance 2
- json 2
- hmac 2
- spdy 2
- bootstrap 2
- hateoas 2
- web workers 2
- web intents 2
- geo 2
- webaudio 2
- express.js 2
- angular.js 2
- rxjava 2
- open data 2
- monad 2
- slack 2
- microservices 2
- angular2 2
- angular 2
- kubernetes 2
- d3 2
- haskell 2
- fp 2
- kafka 2
- rust 2
- mule 1
- postgis 1
- exclusion 1
- wildcard 1
- maven 1
- querulous 1
- documentation 1
- client-certificates 1
- security 1
- knockout.js 1
- amqp 1
- rabbitmq 1
- box2d 1
- impedance mismatch 1
- open source 1
- mac 1
- svg 1
- geolocation 1
- word 1
- firefox 1
- android 1
- twitter 1
- cloud 1
- pointer lock 1
- webapi 1
- css 1
- jquery 1
- audio 1
- tutorial 1
- jqueryui 1
- desktop notifications 1
- dat.gui 1
- overview 1
- three 1
- spray 1
- streams 1
- examples 1
- books 1
- scala.js 1
- devops 1
- sonar 1
- statsd 1
- granafa 1
- influxdb 1
- type class 1
- example 1
- typeclass 1
- actors akka-typed 1
- scalatest 1
- selenium 1
- ensime 1
- atom 1
- blender 1
- scala-native 1
- voronoi d3.js 1
- threejs 1
- arrow 1
- webflux 1
- kotlin 1
- puppeteer 1
- git 1
- dns 1
- apollo 1
- websocket 1
- graphql 1
- node 1
- command line 1
- bash 1
- zsh 1
- cats 1
- dev 1
- nix 1
- nix-shell 1
posts
Exploring ZIO - Part II - ZStream and modules
In the previous article we looked at the basics of ZIO. In this part we’re going to extend on that example and add the following: ZStream integration: we...
Exploring ZIO - Part I
I’ve done a lot of Kotlin for the last two years, and have mainly followed Scala and done some pet projects. Since a lot of interesting stuff has been going ...
Running a minimal Kafka instance on K8S
A couple of days ago I ran into an issue with our hosted Kafka environment, and we had to give a demo. So I was looking for a quick way to run a simple ephem...
My 10 goto terminal commands
There are a lot of useful terminal/shell commands which can make your live a lot easier. I do a lot of backend development, and there is a set of commands wh...
Getting started with Rust - part 2
In the previous article I started experimenting with Rust and build a very simple extension to git, which helps me remember the most recent branches I’ve bee...
Getting started with Rust - part 1
I decided to look a bit into Rust. I’ve been hearing great things about it, the community seems to be (mostly) very inviting and open, and the language in it...
Running puppeteer headless with extensions in docker
Puppeteer (https://github.com/puppeteer/puppeteer) is a great way to write scrapers, integration tests, or automate boring tasks and web forms. For a lot of ...
Setting up a simple Kafka cluster with docker for testing
In this short article we’ll have a quick look at how to set up a Kafka cluster locally, which can be easily accessed from outside of the docker container. ...
Scala/Kotlin developer learning Haskell - Part 2 - Monad Transformers
In the previous article learning haskell part 1 I walked through the steps I took to get a very simple and basic REST endpoint up and running. All that wen...
Scala/Kotlin developer learning Haskell - Part 1 - Rest endpoint with JSON
I’ve been doing scala and FP for a while now, and during that time I’ve tried a couple of times to pickup haskell as well. What I noticed was that I knew to...
Getting started with FP in Kotlin and Arrow: Typeclasses
I’ve recently made the effort to try and pick up Kotlin (again). The last couple of years I’ve been doing mostly scala work (with some other languages in b...
All (150+) learning three.js third edition examples online
A couple of months ago the third edtion of my book on learning three.js was released: View on Packt. Just as for the previous examples I’ve put all the examp...
D3.js: Devoxx presentation 2017
I just noticed that I never published the D3.js presentation I gave last year on Devoxx. So a bit late, but you can find the video for that presentation belo...
10 Practical Kubernetes Tips for Day to Day Kubernetes usage
A couple of years ago I wrote a number of articles on how to work with docker. Since that time a lot has changed in the docker and container world. Docker ha...
Three.js: Devoxx presentation 2018
Hi everyone,
Voronoi Fractal with D3.js
I’ve been very busy the last couple of months. Started a new project at Philips, started writing on D3.js for Packt, and besides that participating in two st...
Dynamic component loading with Angular2: replace $compile
Note that this has become outdated… again. But it has become part of the standard Angular distribution. Please look at the latest angular documentation here:...
Analyzing swearing in movies Part 1: Swears per minute
In this short article I’d like to explain the process I took to create some simple D3.js visualizations based on the number of swears per minute in movies. I...
First steps with Angular 2: 8 cool features
I’ve been doing some work the last couple of weeks with Angular2. I really like it. Not just because it uses typescript, but also because it feels really nat...
Scalaz features for everyday usage part 3: State Monad, Writer Monad and lenses
In this article in the mini series on Scalaz, we'll look at a couple of additional monads and patterns available in Scalaz. Once again, we'll look at stuff t...
Getting started with scala-native
This is just a quick recollection of the steps I've taken to get my own helloworld running using scala-native. I haven't really started looking at scala-nati...
Render 3D Star Wars: The Force Awakens models in Blender and Three.js
Recently video copilot released a free set of high-definition professional grade 3D models (which you can download for yourself from here). This model pack, ...
Service Discovery with Docker and Consul: part 2
So, welcome to the second part of the series on using Consul for service discovey together with docker. In this second article we'll look at how you can use ...
Scalaz features for everyday usage part 2: Monad Transformers and the Reader Monad
For the second article of the "Scalaz features for everyday usage" we'll look at the subject of Monad transformers and the Reader monad.Let's start with Mona...
Service Discovery with Docker and Consul: part 1
During the last year I've become a big fan of using Consul for all things related to service discovery. If you're doing microservices you've probably ran int...
Presentation: Service discovery in a microservice architecture
I recently gave a presentation on how you can use Consul (http://consul.io) for all your service discovery needs in a microservice architecture. The present...
Developing Scala in Atom with Ensime
When I began Java software development way back in the time of Java 1.3 I remember using JDeveloper for a time, before switching to the early versions of Ecl...
Website scraping using Selenium, Docker and Chrome with Extensions.
For a specific project we needed a quick way to get the content of a specific URL and check whether a word was present in the text there. If all we had to s...
Create a Slack Docker proxy in Go - Part 2
In the previous article we had a look at how you could easily create a slack-docker-proxy using go and a couple of small libraries. In this second article we...
Create a Slack Docker proxy in Go - Part 1
Last year I had the opportunity to work with lots of cool tools and technologies. A couple of those were go, slack and docker. We pretty much use slack for a...
10 Practical Docker Tips for Day to Day Docker usage
I’ve had the opportunity to setup a complete new docker based microservice architecture at my current job, so since everyone is sharing their docker tips and...
Akka Typed Actors: Exploring the receptionist pattern
In this article we’ll explore another of Akka-Typed patterns. This time we’ll show you how you can use the receptionist patterns. This is the third and last ...
Two-way SSL (client certificates) with Scalatest
At work we recently added the option to authenticate machine to machine communication using client certificates (two-way ssl). While this was relatively easy...
Akka Typed Actors: Exploring the receiver pattern
In the previous article we looked at some of the basic features provided by Akka Typed. In this article and the next one we’ll look a bit closer at some more...
Akka Typed: First steps with typed actors in Scala
With the release of Akka 2.4.0 a couple of weeks ago the experimental Akka Typed module was added. With Akka Typed it is possible to create and interact with...
Listen to notifications from Postgresql with Scala
In the past I’ve written a couple of articles (Building a REST service in Scala with Akka HTTP, Akka Streams and reactive mongo and ReactiveMongo with Akka, ...
Scala typeclass explained: Implement a String.read function
In this short article I’d like to explain how you can use the typeclass pattern in Scala to implement adhoc polymorphism. We won’t go into too much theoretic...
Easy validation in Scala using Scalaz, Readers and ValidationNel
I’m working on a new book for Packt which shows how you can use various Scala frameworks to create REST services. For this book I’m looking at the following...
Exploring the HTML5 Web Audio API: Filters
03-07-2015 Update: Updated the example, it now works with the latest versions of Chrome and Firefox With the Web Audio API you can have advanced audio pro...
Backpressure in action with websockets and akka-streams
So in the previous article I showed how you could create a websocket server using akka-streams. In this follow up article we’ll look a bit closer on how bac...
Create a reactive websocket server with akka-streams
In the previous article we looked at how backpressure works when working with akka-streams. Akka also uses akka-streams as the base for akka-http, with which...
Visualizing back pressure and reactive streams with akka-streams, statsd, grafana and influxdb
Currently reactive programming is getting more and more attentions. With reactive programming it is possible to easily create resilient, scalable and fault t...
Migrate sonar data from old to new sonar version
At my current project we were setting up a new buildserver. One of the things we had to do was move an old sonar implementation running on top of H2 to a new...
Creating an Angular.js application without JavaScript: Scala.js
In my day job I work a lot with Angular.js. And while this is a great framework, sometimes I do miss the type-safety and advanced features of languages such ...
Using Go to build a REST service on top of mongoDB
I’ve been following go (go-lang) for a while now and finally had some time to experiment with it a bit more. In this post we’ll create a simple HTTP server ...
All 80+ recipes from Three.js Cookbook online
About a month ago my third book on Three.js got released: Three.js Cookbook. This book has 80+ recipes on how to accomplish common tasks in Three.js. On this...
Building a REST service in Scala with Akka HTTP, Akka Streams and reactive mongo
At the end of last year I wrote a couple of articles that showed how you can use Spray.io to create a Scala based REST service () and how to create a websock...
Scala snippets 4: Pimp my library pattern with type classes.
I wanted to write an article on the fun parts of scalaz, but thought it would be best to first look a bit closer at the type classes system provided by scala...
Scala snippets 3: Lists together with Map, flatmap, zip and reduce
You can’t really talk about scala without going into the details of the Map, flatMap, zip and reduce functions. With these functions it is very easy to proce...
Scala snippets 2: List symbol magic
The following snippets are available: Scala snippets 1: Folding Scala snippets 2: List symbol magic Scala snippets 3: Lists together with Map, flatmap,...
Scala snippets 1: Folding
Coming from a Java background, Scala provides lots of nice features and libraries that allow you to create nice and concise code. Wrapping your head around t...
ReactiveMongo with Akka, Scala and websockets
I was looking for a simple websocket server for one of my projects to test some stuff with reactive mongo. When looking around, though, I couldn’t really fin...
Use reactive streams API to combine akka-streams with rxJava
Just a quick article this time, since I’m still experimenting with this stuff. There is a lot of talk around reactive programming. In Java 8 we’ve got the St...
First steps with REST, Spray and Scala
On this site you can already find a couple of articles on how to do REST with a multiple of different frameworks. You can find an old one on Play, some on Sc...
Access information from GeoTIFF using Java
I’m always very interested in combining information from various open data sources together. The last couple of weeks I’ve been working with GIS related info...
Widgets and dashboard with Atlasboard, Node.js and d3.js
So it’s been a while since I added something to this blog. I’ve been very busy with work and at the same time finishing up my second book on Three.js. For ou...
Create global precipitation (rain) visualizations with HTML5, Canvas, and open data
I’m currently working on my next book for Three.js and one of the chapters deals with visualizing open data. When looking around for data that I could use, I...
Browser to browser communication with Vert.x, websockets and HTML5
I’ve been playing around with Vert.x for a couple of weeks and I’m really starting to like the simplicity of the framework. With very little configuration yo...
Win a Free Copy of Packt’s Learning Three.js: The JavaScript 3D Library for WebGL
We are pleased to announce that we are organizing a giveaway especially for you. All you need to do is just comment below the post and win a free copy of Lea...
Capture Canvas and WebGL output as video using websockets
About a month ago I got the request to create a video from one of the WebGL demos on this site (the rotating earth cube, showing population density). So, of ...
All 109 Examples from my book on Three.js for Three.js version r63
A couple of months ago my book on Three.js was published by packt (which you can buy from here: Learning Three.js: The JavaScript 3D Library for WebGL). All ...
Create a simpe RESTful service with vert.x 2.0, RxJava and mongoDB
A new article after an hiatus of almost half a year. In this article we’ll have quick look at how you can get started with vert.x and more interestingly how ...
The Truth About HTML5
I work for Malmberg, which is a publisher of educational content. Within our company we have a lot of very interactive content that is currently made availab...
Movie color analysis with XBMC, Boblight, Java and D3.js
It’s been a while since I blogged, but it has been a rather busy time. Lots of big projects at work that need my complete attention, and lots of personal stu...
Quickly create GUI for javascript variables with dat.GUI
I’m currently working on a book for Three.js. This book contains lots and lots of examples that show off the various features of this great library. I want r...
Chrome and Firefox: Desktop Notifications
Just a short article this time, since I’m kind of swamped with work and the start of a new book on Three.js I’m writing for Packt. In this article we’ll very...
CPI Interactive index (15 years) created with Angular.js, bootstrap and d3.js
Long time since I posted anything. But it’s been a busy time with the holidays a new job and a week of snowboarding :) So after this short hiatus a quick art...
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...
scala
Exploring Cats Effect
In two previous articles we explored how you can use ZIO to easily create programs in a type-safe manner: Exploring ZIO - Part I Exploring ZIO - Part I...
Exploring ZIO - Part II - ZStream and modules
In the previous article we looked at the basics of ZIO. In this part we’re going to extend on that example and add the following: ZStream integration: we...
Exploring ZIO - Part I
I’ve done a lot of Kotlin for the last two years, and have mainly followed Scala and done some pet projects. Since a lot of interesting stuff has been going ...
Scalaz features for everyday usage part 3: State Monad, Writer Monad and lenses
In this article in the mini series on Scalaz, we'll look at a couple of additional monads and patterns available in Scalaz. Once again, we'll look at stuff t...
Getting started with scala-native
This is just a quick recollection of the steps I've taken to get my own helloworld running using scala-native. I haven't really started looking at scala-nati...
Scalaz features for everyday usage part 2: Monad Transformers and the Reader Monad
For the second article of the "Scalaz features for everyday usage" we'll look at the subject of Monad transformers and the Reader monad.Let's start with Mona...
Scalaz features for everyday usage part 1: Typeclasses and Scala extensions
Most of you have probably heard of the great Javascript book: Javascript the good parts. In the same light I'd like to show some stuff from Scalaz which are ...
Developing Scala in Atom with Ensime
When I began Java software development way back in the time of Java 1.3 I remember using JDeveloper for a time, before switching to the early versions of Ecl...
Website scraping using Selenium, Docker and Chrome with Extensions.
For a specific project we needed a quick way to get the content of a specific URL and check whether a word was present in the text there. If all we had to s...
Akka Typed Actors: Exploring the receptionist pattern
In this article we’ll explore another of Akka-Typed patterns. This time we’ll show you how you can use the receptionist patterns. This is the third and last ...
Two-way SSL (client certificates) with Scalatest
At work we recently added the option to authenticate machine to machine communication using client certificates (two-way ssl). While this was relatively easy...
Akka Typed Actors: Exploring the receiver pattern
In the previous article we looked at some of the basic features provided by Akka Typed. In this article and the next one we’ll look a bit closer at some more...
Akka Typed: First steps with typed actors in Scala
With the release of Akka 2.4.0 a couple of weeks ago the experimental Akka Typed module was added. With Akka Typed it is possible to create and interact with...
Listen to notifications from Postgresql with Scala
In the past I’ve written a couple of articles (Building a REST service in Scala with Akka HTTP, Akka Streams and reactive mongo and ReactiveMongo with Akka, ...
Scala typeclass explained: Implement a String.read function
In this short article I’d like to explain how you can use the typeclass pattern in Scala to implement adhoc polymorphism. We won’t go into too much theoretic...
Easy validation in Scala using Scalaz, Readers and ValidationNel
I’m working on a new book for Packt which shows how you can use various Scala frameworks to create REST services. For this book I’m looking at the following...
Backpressure in action with websockets and akka-streams
So in the previous article I showed how you could create a websocket server using akka-streams. In this follow up article we’ll look a bit closer on how bac...
Create a reactive websocket server with akka-streams
In the previous article we looked at how backpressure works when working with akka-streams. Akka also uses akka-streams as the base for akka-http, with which...
Creating an Angular.js application without JavaScript: Scala.js
In my day job I work a lot with Angular.js. And while this is a great framework, sometimes I do miss the type-safety and advanced features of languages such ...
Building a REST service in Scala with Akka HTTP, Akka Streams and reactive mongo
At the end of last year I wrote a couple of articles that showed how you can use Spray.io to create a Scala based REST service () and how to create a websock...
Scala snippets 4: Pimp my library pattern with type classes.
I wanted to write an article on the fun parts of scalaz, but thought it would be best to first look a bit closer at the type classes system provided by scala...
Scala snippets 3: Lists together with Map, flatmap, zip and reduce
You can’t really talk about scala without going into the details of the Map, flatMap, zip and reduce functions. With these functions it is very easy to proce...
Scala snippets 2: List symbol magic
The following snippets are available: Scala snippets 1: Folding Scala snippets 2: List symbol magic Scala snippets 3: Lists together with Map, flatmap,...
Scala snippets 1: Folding
Coming from a Java background, Scala provides lots of nice features and libraries that allow you to create nice and concise code. Wrapping your head around t...
ReactiveMongo with Akka, Scala and websockets
I was looking for a simple websocket server for one of my projects to test some stuff with reactive mongo. When looking around, though, I couldn’t really fin...
Use reactive streams API to combine akka-streams with rxJava
Just a quick article this time, since I’m still experimenting with this stuff. There is a lot of talk around reactive programming. In Java 8 we’ve got the St...
First steps with REST, Spray and Scala
On this site you can already find a couple of articles on how to do REST with a multiple of different frameworks. You can find an old one on Play, some on Sc...
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 ...
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...
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...
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 ...
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...
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...
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...
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, ...
html5
Exploring the HTML5 Web Audio API: Filters
03-07-2015 Update: Updated the example, it now works with the latest versions of Chrome and Firefox With the Web Audio API you can have advanced audio pro...
Create global precipitation (rain) visualizations with HTML5, Canvas, and open data
I’m currently working on my next book for Three.js and one of the chapters deals with visualizing open data. When looking around for data that I could use, I...
Browser to browser communication with Vert.x, websockets and HTML5
I’ve been playing around with Vert.x for a couple of weeks and I’m really starting to like the simplicity of the framework. With very little configuration yo...
Capture Canvas and WebGL output as video using websockets
About a month ago I got the request to create a video from one of the WebGL demos on this site (the rotating earth cube, showing population density). So, of ...
The Truth About HTML5
I work for Malmberg, which is a publisher of educational content. Within our company we have a lot of very interactive content that is currently made availab...
Chrome and Firefox: Desktop Notifications
Just a short article this time, since I’m kind of swamped with work and the start of a new book on Three.js I’m writing for Packt. In this article we’ll very...
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 ...
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...
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...
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...
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...
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...
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...
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...
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...
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...
javascript
All 109 Examples from my book on Three.js for Three.js version r63
A couple of months ago my book on Three.js was published by packt (which you can buy from here: Learning Three.js: The JavaScript 3D Library for WebGL). All ...
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...
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...
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...
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...
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...
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...
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...
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...
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...
three.js
All (150+) learning three.js third edition examples online
A couple of months ago the third edtion of my book on learning three.js was released: View on Packt. Just as for the previous examples I’ve put all the examp...
Render 3D Star Wars: The Force Awakens models in Blender and Three.js
Recently video copilot released a free set of high-definition professional grade 3D models (which you can download for yourself from here). This model pack, ...
All 80+ recipes from Three.js Cookbook online
About a month ago my third book on Three.js got released: Three.js Cookbook. This book has 80+ recipes on how to accomplish common tasks in Three.js. On this...
Win a Free Copy of Packt’s Learning Three.js: The JavaScript 3D Library for WebGL
We are pleased to announce that we are organizing a giveaway especially for you. All you need to do is just comment below the post and win a free copy of Lea...
Capture Canvas and WebGL output as video using websockets
About a month ago I got the request to create a video from one of the WebGL demos on this site (the rotating earth cube, showing population density). So, of ...
All 109 Examples from my book on Three.js for Three.js version r63
A couple of months ago my book on Three.js was published by packt (which you can buy from here: Learning Three.js: The JavaScript 3D Library for WebGL). All ...
Quickly create GUI for javascript variables with dat.GUI
I’m currently working on a book for Three.js. This book contains lots and lots of examples that show off the various features of this great library. I want r...
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 ...
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...
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...
rest
Using Go to build a REST service on top of mongoDB
I’ve been following go (go-lang) for a while now and finally had some time to experiment with it a bit more. In this post we’ll create a simple HTTP server ...
Building a REST service in Scala with Akka HTTP, Akka Streams and reactive mongo
At the end of last year I wrote a couple of articles that showed how you can use Spray.io to create a Scala based REST service () and how to create a websock...
First steps with REST, Spray and Scala
On this site you can already find a couple of articles on how to do REST with a multiple of different frameworks. You can find an old one on Play, some on Sc...
Create a simpe RESTful service with vert.x 2.0, RxJava and mongoDB
A new article after an hiatus of almost half a year. In this article we’ll have quick look at how you can get started with vert.x and more interestingly how ...
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...
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...
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...
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...
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...
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...
d3.js
Analyzing swearing in movies Part 1: Swears per minute
In this short article I’d like to explain the process I took to create some simple D3.js visualizations based on the number of swears per minute in movies. I...
Widgets and dashboard with Atlasboard, Node.js and d3.js
So it’s been a while since I added something to this blog. I’ve been very busy with work and at the same time finishing up my second book on Three.js. For ou...
Movie color analysis with XBMC, Boblight, Java and D3.js
It’s been a while since I blogged, but it has been a rather busy time. Lots of big projects at work that need my complete attention, and lots of personal stu...
CPI Interactive index (15 years) created with Angular.js, bootstrap and d3.js
Long time since I posted anything. But it’s been a busy time with the holidays a new job and a week of snowboarding :) So after this short hiatus a quick art...
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...
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...
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...
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...
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...
java
Use reactive streams API to combine akka-streams with rxJava
Just a quick article this time, since I’m still experimenting with this stuff. There is a lot of talk around reactive programming. In Java 8 we’ve got the St...
Access information from GeoTIFF using Java
I’m always very interested in combining information from various open data sources together. The last couple of weeks I’ve been working with GIS related info...
Movie color analysis with XBMC, Boblight, Java and D3.js
It’s been a while since I blogged, but it has been a rather busy time. Lots of big projects at work that need my complete attention, and lots of personal stu...
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 ...
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...
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...
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...
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...
akka
Akka Typed Actors: Exploring the receptionist pattern
In this article we’ll explore another of Akka-Typed patterns. This time we’ll show you how you can use the receptionist patterns. This is the third and last ...
Akka Typed Actors: Exploring the receiver pattern
In the previous article we looked at some of the basic features provided by Akka Typed. In this article and the next one we’ll look a bit closer at some more...
Akka Typed: First steps with typed actors in Scala
With the release of Akka 2.4.0 a couple of weeks ago the experimental Akka Typed module was added. With Akka Typed it is possible to create and interact with...
Listen to notifications from Postgresql with Scala
In the past I’ve written a couple of articles (Building a REST service in Scala with Akka HTTP, Akka Streams and reactive mongo and ReactiveMongo with Akka, ...
Backpressure in action with websockets and akka-streams
So in the previous article I showed how you could create a websocket server using akka-streams. In this follow up article we’ll look a bit closer on how bac...
Create a reactive websocket server with akka-streams
In the previous article we looked at how backpressure works when working with akka-streams. Akka also uses akka-streams as the base for akka-http, with which...
Visualizing back pressure and reactive streams with akka-streams, statsd, grafana and influxdb
Currently reactive programming is getting more and more attentions. With reactive programming it is possible to easily create resilient, scalable and fault t...
Building a REST service in Scala with Akka HTTP, Akka Streams and reactive mongo
At the end of last year I wrote a couple of articles that showed how you can use Spray.io to create a Scala based REST service () and how to create a websock...
ReactiveMongo with Akka, Scala and websockets
I was looking for a simple websocket server for one of my projects to test some stuff with reactive mongo. When looking around, though, I couldn’t really fin...
docker
Setting up a simple Kafka cluster with docker for testing
In this short article we’ll have a quick look at how to set up a Kafka cluster locally, which can be easily accessed from outside of the docker container. ...
10 Practical Kubernetes Tips for Day to Day Kubernetes usage
A couple of years ago I wrote a number of articles on how to work with docker. Since that time a lot has changed in the docker and container world. Docker ha...
Service Discovery with Docker and Consul: part 2
So, welcome to the second part of the series on using Consul for service discovey together with docker. In this second article we'll look at how you can use ...
Service Discovery with Docker and Consul: part 1
During the last year I've become a big fan of using Consul for all things related to service discovery. If you're doing microservices you've probably ran int...
Website scraping using Selenium, Docker and Chrome with Extensions.
For a specific project we needed a quick way to get the content of a specific URL and check whether a word was present in the text there. If all we had to s...
Create a Slack Docker proxy in Go - Part 2
In the previous article we had a look at how you could easily create a slack-docker-proxy using go and a couple of small libraries. In this second article we...
Create a Slack Docker proxy in Go - Part 1
Last year I had the opportunity to work with lots of cool tools and technologies. A couple of those were go, slack and docker. We pretty much use slack for a...
10 Practical Docker Tips for Day to Day Docker usage
I’ve had the opportunity to setup a complete new docker based microservice architecture at my current job, so since everyone is sharing their docker tips and...
chrome
Website scraping using Selenium, Docker and Chrome with Extensions.
For a specific project we needed a quick way to get the content of a specific URL and check whether a word was present in the text there. If all we had to s...
Exploring the HTML5 Web Audio API: Filters
03-07-2015 Update: Updated the example, it now works with the latest versions of Chrome and Firefox With the Web Audio API you can have advanced audio pro...
Chrome and Firefox: Desktop Notifications
Just a short article this time, since I’m kind of swamped with work and the start of a new book on Three.js I’m writing for Packt. In this article we’ll very...
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...
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...
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...
webgl
Render 3D Star Wars: The Force Awakens models in Blender and Three.js
Recently video copilot released a free set of high-definition professional grade 3D models (which you can download for yourself from here). This model pack, ...
Win a Free Copy of Packt’s Learning Three.js: The JavaScript 3D Library for WebGL
We are pleased to announce that we are organizing a giveaway especially for you. All you need to do is just comment below the post and win a free copy of Lea...
Capture Canvas and WebGL output as video using websockets
About a month ago I got the request to create a video from one of the WebGL demos on this site (the rotating earth cube, showing population density). So, of ...
All 109 Examples from my book on Three.js for Three.js version r63
A couple of months ago my book on Three.js was published by packt (which you can buy from here: Learning Three.js: The JavaScript 3D Library for WebGL). All ...
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...
websockets
Create a reactive websocket server with akka-streams
In the previous article we looked at how backpressure works when working with akka-streams. Akka also uses akka-streams as the base for akka-http, with which...
Browser to browser communication with Vert.x, websockets and HTML5
I’ve been playing around with Vert.x for a couple of weeks and I’m really starting to like the simplicity of the framework. With very little configuration yo...
Capture Canvas and WebGL output as video using websockets
About a month ago I got the request to create a video from one of the WebGL demos on this site (the rotating earth cube, showing population density). So, of ...
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...
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...
reactive
Backpressure in action with websockets and akka-streams
So in the previous article I showed how you could create a websocket server using akka-streams. In this follow up article we’ll look a bit closer on how bac...
Visualizing back pressure and reactive streams with akka-streams, statsd, grafana and influxdb
Currently reactive programming is getting more and more attentions. With reactive programming it is possible to easily create resilient, scalable and fault t...
Building a REST service in Scala with Akka HTTP, Akka Streams and reactive mongo
At the end of last year I wrote a couple of articles that showed how you can use Spray.io to create a Scala based REST service () and how to create a websock...
ReactiveMongo with Akka, Scala and websockets
I was looking for a simple websocket server for one of my projects to test some stuff with reactive mongo. When looking around, though, I couldn’t really fin...
Use reactive streams API to combine akka-streams with rxJava
Just a quick article this time, since I’m still experimenting with this stuff. There is a lot of talk around reactive programming. In Java 8 we’ve got the St...
ssl
Two-way SSL (client certificates) with Scalatest
At work we recently added the option to authenticate machine to machine communication using client certificates (two-way ssl). While this was relatively easy...
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...
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...
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...
jetty
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...
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...
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...
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...
play
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 ...
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...
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...
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...
webrtc
Exploring the HTML5 Web Audio API: Filters
03-07-2015 Update: Updated the example, it now works with the latest versions of Chrome and Firefox With the Web Audio API you can have advanced audio pro...
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...
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...
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...
scalatra
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 ...
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...
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...
visualization
Getting started with FP in Kotlin and Arrow: Typeclasses
I’ve recently made the effort to try and pick up Kotlin (again). The last couple of years I’ve been doing mostly scala work (with some other languages in b...
Analyzing swearing in movies Part 1: Swears per minute
In this short article I’d like to explain the process I took to create some simple D3.js visualizations based on the number of swears per minute in movies. I...
Movie color analysis with XBMC, Boblight, Java and D3.js
It’s been a while since I blogged, but it has been a rather busy time. Lots of big projects at work that need my complete attention, and lots of personal stu...
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...
snippets
Scala snippets 4: Pimp my library pattern with type classes.
I wanted to write an article on the fun parts of scalaz, but thought it would be best to first look a bit closer at the type classes system provided by scala...
Scala snippets 3: Lists together with Map, flatmap, zip and reduce
You can’t really talk about scala without going into the details of the Map, flatMap, zip and reduce functions. With these functions it is very easy to proce...
Scala snippets 2: List symbol magic
The following snippets are available: Scala snippets 1: Folding Scala snippets 2: List symbol magic Scala snippets 3: Lists together with Map, flatmap,...
Scala snippets 1: Folding
Coming from a Java background, Scala provides lots of nice features and libraries that allow you to create nice and concise code. Wrapping your head around t...
scalaz
Scalaz features for everyday usage part 3: State Monad, Writer Monad and lenses
In this article in the mini series on Scalaz, we'll look at a couple of additional monads and patterns available in Scalaz. Once again, we'll look at stuff t...
Scalaz features for everyday usage part 2: Monad Transformers and the Reader Monad
For the second article of the "Scalaz features for everyday usage" we'll look at the subject of Monad transformers and the Reader monad.Let's start with Mona...
Scalaz features for everyday usage part 1: Typeclasses and Scala extensions
Most of you have probably heard of the great Javascript book: Javascript the good parts. In the same light I'd like to show some stuff from Scalaz which are ...
Easy validation in Scala using Scalaz, Readers and ValidationNel
I’m working on a new book for Packt which shows how you can use various Scala frameworks to create REST services. For this book I’m looking at the following...
typescript
Standalone Apollo Graphql Websocket Subscriptions
This is just a quick article on how to create a simple standalone Apollo client to test Graphql subscriptions. I needed something like this when we ran into...
Running puppeteer headless with extensions in docker
Puppeteer (https://github.com/puppeteer/puppeteer) is a great way to write scrapers, integration tests, or automate boring tasks and web forms. For a lot of ...
Dynamic component loading with Angular2: replace $compile
Note that this has become outdated… again. But it has become part of the standard Angular distribution. Please look at the latest angular documentation here:...
First steps with Angular 2: 8 cool features
I’ve been doing some work the last couple of weeks with Angular2. I really like it. Not just because it uses typescript, but also because it feels really nat...
gis
Access information from GeoTIFF using Java
I’m always very interested in combining information from various open data sources together. The last couple of weeks I’ve been working with GIS related info...
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...
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...
canvas
Create global precipitation (rain) visualizations with HTML5, Canvas, and open data
I’m currently working on my next book for Three.js and one of the chapters deals with visualizing open data. When looking around for data that I could use, I...
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...
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...
debugging
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...
node.js
Widgets and dashboard with Atlasboard, Node.js and d3.js
So it’s been a while since I added something to this blog. I’ve been very busy with work and at the same time finishing up my second book on Three.js. For ou...
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 ...
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...
angularjs
Creating an Angular.js application without JavaScript: Scala.js
In my day job I work a lot with Angular.js. And while this is a great framework, sometimes I do miss the type-safety and advanced features of languages such ...
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...
mongodb
Using Go to build a REST service on top of mongoDB
I’ve been following go (go-lang) for a while now and finally had some time to experiment with it a bit more. In this post we’ll create a simple HTTP server ...
ReactiveMongo with Akka, Scala and websockets
I was looking for a simple websocket server for one of my projects to test some stuff with reactive mongo. When looking around, though, I couldn’t really fin...
Create a simpe RESTful service with vert.x 2.0, RxJava and mongoDB
A new article after an hiatus of almost half a year. In this article we’ll have quick look at how you can get started with vert.x and more interestingly how ...
vert.x
Browser to browser communication with Vert.x, websockets and HTML5
I’ve been playing around with Vert.x for a couple of weeks and I’m really starting to like the simplicity of the framework. With very little configuration yo...
Capture Canvas and WebGL output as video using websockets
About a month ago I got the request to create a video from one of the WebGL demos on this site (the rotating earth cube, showing population density). So, of ...
Create a simpe RESTful service with vert.x 2.0, RxJava and mongoDB
A new article after an hiatus of almost half a year. In this article we’ll have quick look at how you can get started with vert.x and more interestingly how ...
go-lang
Create a Slack Docker proxy in Go - Part 2
In the previous article we had a look at how you could easily create a slack-docker-proxy using go and a couple of small libraries. In this second article we...
Create a Slack Docker proxy in Go - Part 1
Last year I had the opportunity to work with lots of cool tools and technologies. A couple of those were go, slack and docker. We pretty much use slack for a...
Using Go to build a REST service on top of mongoDB
I’ve been following go (go-lang) for a while now and finally had some time to experiment with it a bit more. In this post we’ll create a simple HTTP server ...
go
Create a Slack Docker proxy in Go - Part 2
In the previous article we had a look at how you could easily create a slack-docker-proxy using go and a couple of small libraries. In this second article we...
Create a Slack Docker proxy in Go - Part 1
Last year I had the opportunity to work with lots of cool tools and technologies. A couple of those were go, slack and docker. We pretty much use slack for a...
Using Go to build a REST service on top of mongoDB
I’ve been following go (go-lang) for a while now and finally had some time to experiment with it a bit more. In this post we’ll create a simple HTTP server ...
akka-streams
Backpressure in action with websockets and akka-streams
So in the previous article I showed how you could create a websocket server using akka-streams. In this follow up article we’ll look a bit closer on how bac...
Create a reactive websocket server with akka-streams
In the previous article we looked at how backpressure works when working with akka-streams. Akka also uses akka-streams as the base for akka-http, with which...
Visualizing back pressure and reactive streams with akka-streams, statsd, grafana and influxdb
Currently reactive programming is getting more and more attentions. With reactive programming it is possible to easily create resilient, scalable and fault t...
top
My 10 goto terminal commands
There are a lot of useful terminal/shell commands which can make your live a lot easier. I do a lot of backend development, and there is a set of commands wh...
10 Practical Kubernetes Tips for Day to Day Kubernetes usage
A couple of years ago I wrote a number of articles on how to work with docker. Since that time a lot has changed in the docker and container world. Docker ha...
10 Practical Docker Tips for Day to Day Docker usage
I’ve had the opportunity to setup a complete new docker based microservice architecture at my current job, so since everyone is sharing their docker tips and...
consul
Service Discovery with Docker and Consul: part 2
So, welcome to the second part of the series on using Consul for service discovey together with docker. In this second article we'll look at how you can use ...
Service Discovery with Docker and Consul: part 1
During the last year I've become a big fan of using Consul for all things related to service discovery. If you're doing microservices you've probably ran int...
Presentation: Service discovery in a microservice architecture
I recently gave a presentation on how you can use Consul (http://consul.io) for all your service discovery needs in a microservice architecture. The present...
devoxx
All (150+) learning three.js third edition examples online
A couple of months ago the third edtion of my book on learning three.js was released: View on Packt. Just as for the previous examples I’ve put all the examp...
D3.js: Devoxx presentation 2017
I just noticed that I never published the D3.js presentation I gave last year on Devoxx. So a bit late, but you can find the video for that presentation belo...
Three.js: Devoxx presentation 2018
Hi everyone,
k8s
Exploring ZIO - Part II - ZStream and modules
In the previous article we looked at the basics of ZIO. In this part we’re going to extend on that example and add the following: ZStream integration: we...
Exploring ZIO - Part I
I’ve done a lot of Kotlin for the last two years, and have mainly followed Scala and done some pet projects. Since a lot of interesting stuff has been going ...
Running a minimal Kafka instance on K8S
A couple of days ago I ran into an issue with our hosted Kafka environment, and we had to give a demo. So I was looking for a quick way to run a simple ephem...
zio
Exploring Cats Effect
In two previous articles we explored how you can use ZIO to easily create programs in a type-safe manner: Exploring ZIO - Part I Exploring ZIO - Part I...
Exploring ZIO - Part II - ZStream and modules
In the previous article we looked at the basics of ZIO. In this part we’re going to extend on that example and add the following: ZStream integration: we...
Exploring ZIO - Part I
I’ve done a lot of Kotlin for the last two years, and have mainly followed Scala and done some pet projects. Since a lot of interesting stuff has been going ...
wso2
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 ...
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...
postgresql
Listen to notifications from Postgresql with Scala
In the past I’ve written a couple of articles (Building a REST service in Scala with Akka HTTP, Akka Streams and reactive mongo and ReactiveMongo with Akka, ...
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, ...
governance
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 ...
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...
json
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...
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...
hmac
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...
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...
spdy
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...
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...
bootstrap
CPI Interactive index (15 years) created with Angular.js, bootstrap and d3.js
Long time since I posted anything. But it’s been a busy time with the holidays a new job and a week of snowboarding :) So after this short hiatus a quick art...
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...
hateoas
First steps with REST, Spray and Scala
On this site you can already find a couple of articles on how to do REST with a multiple of different frameworks. You can find an old one on Play, some on Sc...
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...
web workers
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...
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...
web intents
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...
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...
geo
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 ...
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...
webaudio
Exploring the HTML5 Web Audio API: Filters
03-07-2015 Update: Updated the example, it now works with the latest versions of Chrome and Firefox With the Web Audio API you can have advanced audio pro...
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...
express.js
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 ...
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...
angular.js
Creating an Angular.js application without JavaScript: Scala.js
In my day job I work a lot with Angular.js. And while this is a great framework, sometimes I do miss the type-safety and advanced features of languages such ...
CPI Interactive index (15 years) created with Angular.js, bootstrap and d3.js
Long time since I posted anything. But it’s been a busy time with the holidays a new job and a week of snowboarding :) So after this short hiatus a quick art...
rxjava
Use reactive streams API to combine akka-streams with rxJava
Just a quick article this time, since I’m still experimenting with this stuff. There is a lot of talk around reactive programming. In Java 8 we’ve got the St...
Create a simpe RESTful service with vert.x 2.0, RxJava and mongoDB
A new article after an hiatus of almost half a year. In this article we’ll have quick look at how you can get started with vert.x and more interestingly how ...
open data
Access information from GeoTIFF using Java
I’m always very interested in combining information from various open data sources together. The last couple of weeks I’ve been working with GIS related info...
Create global precipitation (rain) visualizations with HTML5, Canvas, and open data
I’m currently working on my next book for Three.js and one of the chapters deals with visualizing open data. When looking around for data that I could use, I...
monad
Scalaz features for everyday usage part 2: Monad Transformers and the Reader Monad
For the second article of the "Scalaz features for everyday usage" we'll look at the subject of Monad transformers and the Reader monad.Let's start with Mona...
Easy validation in Scala using Scalaz, Readers and ValidationNel
I’m working on a new book for Packt which shows how you can use various Scala frameworks to create REST services. For this book I’m looking at the following...
slack
Create a Slack Docker proxy in Go - Part 2
In the previous article we had a look at how you could easily create a slack-docker-proxy using go and a couple of small libraries. In this second article we...
Create a Slack Docker proxy in Go - Part 1
Last year I had the opportunity to work with lots of cool tools and technologies. A couple of those were go, slack and docker. We pretty much use slack for a...
microservices
Service Discovery with Docker and Consul: part 1
During the last year I've become a big fan of using Consul for all things related to service discovery. If you're doing microservices you've probably ran int...
Presentation: Service discovery in a microservice architecture
I recently gave a presentation on how you can use Consul (http://consul.io) for all your service discovery needs in a microservice architecture. The present...
angular2
Dynamic component loading with Angular2: replace $compile
Note that this has become outdated… again. But it has become part of the standard Angular distribution. Please look at the latest angular documentation here:...
First steps with Angular 2: 8 cool features
I’ve been doing some work the last couple of weeks with Angular2. I really like it. Not just because it uses typescript, but also because it feels really nat...
angular
Dynamic component loading with Angular2: replace $compile
Note that this has become outdated… again. But it has become part of the standard Angular distribution. Please look at the latest angular documentation here:...
First steps with Angular 2: 8 cool features
I’ve been doing some work the last couple of weeks with Angular2. I really like it. Not just because it uses typescript, but also because it feels really nat...
kubernetes
Running a minimal Kafka instance on K8S
A couple of days ago I ran into an issue with our hosted Kafka environment, and we had to give a demo. So I was looking for a quick way to run a simple ephem...
10 Practical Kubernetes Tips for Day to Day Kubernetes usage
A couple of years ago I wrote a number of articles on how to work with docker. Since that time a lot has changed in the docker and container world. Docker ha...
d3
Getting started with FP in Kotlin and Arrow: Typeclasses
I’ve recently made the effort to try and pick up Kotlin (again). The last couple of years I’ve been doing mostly scala work (with some other languages in b...
D3.js: Devoxx presentation 2017
I just noticed that I never published the D3.js presentation I gave last year on Devoxx. So a bit late, but you can find the video for that presentation belo...
haskell
Scala/Kotlin developer learning Haskell - Part 2 - Monad Transformers
In the previous article learning haskell part 1 I walked through the steps I took to get a very simple and basic REST endpoint up and running. All that wen...
Scala/Kotlin developer learning Haskell - Part 1 - Rest endpoint with JSON
I’ve been doing scala and FP for a while now, and during that time I’ve tried a couple of times to pickup haskell as well. What I noticed was that I knew to...
fp
Scala/Kotlin developer learning Haskell - Part 2 - Monad Transformers
In the previous article learning haskell part 1 I walked through the steps I took to get a very simple and basic REST endpoint up and running. All that wen...
Scala/Kotlin developer learning Haskell - Part 1 - Rest endpoint with JSON
I’ve been doing scala and FP for a while now, and during that time I’ve tried a couple of times to pickup haskell as well. What I noticed was that I knew to...
kafka
Running a minimal Kafka instance on K8S
A couple of days ago I ran into an issue with our hosted Kafka environment, and we had to give a demo. So I was looking for a quick way to run a simple ephem...
Setting up a simple Kafka cluster with docker for testing
In this short article we’ll have a quick look at how to set up a Kafka cluster locally, which can be easily accessed from outside of the docker container. ...
rust
Getting started with Rust - part 2
In the previous article I started experimenting with Rust and build a very simple extension to git, which helps me remember the most recent branches I’ve bee...
Getting started with Rust - part 1
I decided to look a bit into Rust. I’ve been hearing great things about it, the community seems to be (mostly) very inviting and open, and the language in it...
mule
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...
postgis
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...
exclusion
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...
wildcard
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...
maven
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...
querulous
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, ...
documentation
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...
client-certificates
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...
security
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...
knockout.js
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...
amqp
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...
rabbitmq
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...
box2d
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...
impedance mismatch
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...
open source
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 ...
mac
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 ...
svg
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...
geolocation
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...
word
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 ...
firefox
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...
android
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...
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...
cloud
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 ...
pointer lock
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...
webapi
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...
css
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...
jquery
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...
audio
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...
tutorial
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...
jqueryui
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...
desktop notifications
Chrome and Firefox: Desktop Notifications
Just a short article this time, since I’m kind of swamped with work and the start of a new book on Three.js I’m writing for Packt. In this article we’ll very...
dat.gui
Quickly create GUI for javascript variables with dat.GUI
I’m currently working on a book for Three.js. This book contains lots and lots of examples that show off the various features of this great library. I want r...
overview
The Truth About HTML5
I work for Malmberg, which is a publisher of educational content. Within our company we have a lot of very interactive content that is currently made availab...
three
All 109 Examples from my book on Three.js for Three.js version r63
A couple of months ago my book on Three.js was published by packt (which you can buy from here: Learning Three.js: The JavaScript 3D Library for WebGL). All ...
spray
First steps with REST, Spray and Scala
On this site you can already find a couple of articles on how to do REST with a multiple of different frameworks. You can find an old one on Play, some on Sc...
streams
Building a REST service in Scala with Akka HTTP, Akka Streams and reactive mongo
At the end of last year I wrote a couple of articles that showed how you can use Spray.io to create a Scala based REST service () and how to create a websock...
examples
All 80+ recipes from Three.js Cookbook online
About a month ago my third book on Three.js got released: Three.js Cookbook. This book has 80+ recipes on how to accomplish common tasks in Three.js. On this...
books
All 80+ recipes from Three.js Cookbook online
About a month ago my third book on Three.js got released: Three.js Cookbook. This book has 80+ recipes on how to accomplish common tasks in Three.js. On this...
scala.js
Creating an Angular.js application without JavaScript: Scala.js
In my day job I work a lot with Angular.js. And while this is a great framework, sometimes I do miss the type-safety and advanced features of languages such ...
devops
Migrate sonar data from old to new sonar version
At my current project we were setting up a new buildserver. One of the things we had to do was move an old sonar implementation running on top of H2 to a new...
sonar
Migrate sonar data from old to new sonar version
At my current project we were setting up a new buildserver. One of the things we had to do was move an old sonar implementation running on top of H2 to a new...
statsd
Visualizing back pressure and reactive streams with akka-streams, statsd, grafana and influxdb
Currently reactive programming is getting more and more attentions. With reactive programming it is possible to easily create resilient, scalable and fault t...
granafa
Visualizing back pressure and reactive streams with akka-streams, statsd, grafana and influxdb
Currently reactive programming is getting more and more attentions. With reactive programming it is possible to easily create resilient, scalable and fault t...
influxdb
Visualizing back pressure and reactive streams with akka-streams, statsd, grafana and influxdb
Currently reactive programming is getting more and more attentions. With reactive programming it is possible to easily create resilient, scalable and fault t...
type class
Scala typeclass explained: Implement a String.read function
In this short article I’d like to explain how you can use the typeclass pattern in Scala to implement adhoc polymorphism. We won’t go into too much theoretic...
example
Scala typeclass explained: Implement a String.read function
In this short article I’d like to explain how you can use the typeclass pattern in Scala to implement adhoc polymorphism. We won’t go into too much theoretic...
typeclass
Scala typeclass explained: Implement a String.read function
In this short article I’d like to explain how you can use the typeclass pattern in Scala to implement adhoc polymorphism. We won’t go into too much theoretic...
actors akka-typed
Akka Typed Actors: Exploring the receiver pattern
In the previous article we looked at some of the basic features provided by Akka Typed. In this article and the next one we’ll look a bit closer at some more...
scalatest
Two-way SSL (client certificates) with Scalatest
At work we recently added the option to authenticate machine to machine communication using client certificates (two-way ssl). While this was relatively easy...
selenium
Website scraping using Selenium, Docker and Chrome with Extensions.
For a specific project we needed a quick way to get the content of a specific URL and check whether a word was present in the text there. If all we had to s...
ensime
Developing Scala in Atom with Ensime
When I began Java software development way back in the time of Java 1.3 I remember using JDeveloper for a time, before switching to the early versions of Ecl...
atom
Developing Scala in Atom with Ensime
When I began Java software development way back in the time of Java 1.3 I remember using JDeveloper for a time, before switching to the early versions of Ecl...
blender
Render 3D Star Wars: The Force Awakens models in Blender and Three.js
Recently video copilot released a free set of high-definition professional grade 3D models (which you can download for yourself from here). This model pack, ...
scala-native
Getting started with scala-native
This is just a quick recollection of the steps I've taken to get my own helloworld running using scala-native. I haven't really started looking at scala-nati...
voronoi d3.js
Voronoi Fractal with D3.js
I’ve been very busy the last couple of months. Started a new project at Philips, started writing on D3.js for Packt, and besides that participating in two st...
threejs
Three.js: Devoxx presentation 2018
Hi everyone,
arrow
Webflux with Kotlin and Arrow
A month into the new year and I’m already lagging behind my two articles per month goal. So for Februari I’m going to try and do three articles. To kick of t...
webflux
Webflux with Kotlin and Arrow
A month into the new year and I’m already lagging behind my two articles per month goal. So for Februari I’m going to try and do three articles. To kick of t...
kotlin
Webflux with Kotlin and Arrow
A month into the new year and I’m already lagging behind my two articles per month goal. So for Februari I’m going to try and do three articles. To kick of t...
puppeteer
Running puppeteer headless with extensions in docker
Puppeteer (https://github.com/puppeteer/puppeteer) is a great way to write scrapers, integration tests, or automate boring tasks and web forms. For a lot of ...
git
Getting started with Rust - part 1
I decided to look a bit into Rust. I’ve been hearing great things about it, the community seems to be (mostly) very inviting and open, and the language in it...
dns
Getting started with Rust - part 2
In the previous article I started experimenting with Rust and build a very simple extension to git, which helps me remember the most recent branches I’ve bee...
apollo
Standalone Apollo Graphql Websocket Subscriptions
This is just a quick article on how to create a simple standalone Apollo client to test Graphql subscriptions. I needed something like this when we ran into...
websocket
Standalone Apollo Graphql Websocket Subscriptions
This is just a quick article on how to create a simple standalone Apollo client to test Graphql subscriptions. I needed something like this when we ran into...
graphql
Standalone Apollo Graphql Websocket Subscriptions
This is just a quick article on how to create a simple standalone Apollo client to test Graphql subscriptions. I needed something like this when we ran into...
node
Standalone Apollo Graphql Websocket Subscriptions
This is just a quick article on how to create a simple standalone Apollo client to test Graphql subscriptions. I needed something like this when we ran into...
command line
My 10 goto terminal commands
There are a lot of useful terminal/shell commands which can make your live a lot easier. I do a lot of backend development, and there is a set of commands wh...
bash
My 10 goto terminal commands
There are a lot of useful terminal/shell commands which can make your live a lot easier. I do a lot of backend development, and there is a set of commands wh...
zsh
My 10 goto terminal commands
There are a lot of useful terminal/shell commands which can make your live a lot easier. I do a lot of backend development, and there is a set of commands wh...
cats
Exploring Cats Effect
In two previous articles we explored how you can use ZIO to easily create programs in a type-safe manner: Exploring ZIO - Part I Exploring ZIO - Part I...
dev
Working with nix-shell
Managing runtime dependencies using Nix We’re setting up a new project at work, and wanted to apply some lessons learned from previous projects. One of the ...
nix
Working with nix-shell
Managing runtime dependencies using Nix We’re setting up a new project at work, and wanted to apply some lessons learned from previous projects. One of the ...
nix-shell
Working with nix-shell
Managing runtime dependencies using Nix We’re setting up a new project at work, and wanted to apply some lessons learned from previous projects. One of the ...