Skip to main content

Creating something concrete with Scala

Since I attended a course on functional programming with Scala at Coursera (see previous posts) I've been having a idea to make something concrete with Scala. Having only minimal experience with Scala I decided to try something simple with well known Scala libraries.

The project


First I'll try to create a simple todo application that saves all the data to a some database (maria, redis, mongo) and the tasks are managed via REST-service.

Once I've done that I have two ideas what to do after that. I'll either try to create some sort of UI that uses the REST-service or I'll extend the simple todo application to a Kanban board type of application and try to create the UI after that.

I haven't decided with what I'll be creating the UI since I'm not that familiar with current frontend technologies so that'll be decided later.

First try


At first I tried to create a REST-service with spray but that didn't work. Maybe it's just me but to me the spray documentation was incomplete, I also tried out sprays examples from github and had them running via sbt but not with Scala IDE. The examples ran with sbt but when I tried to create my own REST implementation based on the examples the service never responded. Trying to make this simple service to respond to me with no luck for several hours I decided that I'm not going to use spray.

Second try


This is still on my todo list but next I'll try create the REST-service with Play 2 hopefully with better results.

Impressions now


Trying to create something with a new language and new libraries can be difficult and in case of Scala and spray it seems to be true. Though this isn't true to all languages, I remember a project where we created a REST-service with Grails with absolutely no experience with Groovy or Grails and that was a walk in the park compared to my experiences so far with Scala and spray.

Popular posts from this blog

Sharing to help myself

It's been a while since my last post but I have a good excuse. I've been in a new customer project (well new for me) for two months now and have absorbed a lot of new information on the technology stack and the project itself. This time I'll be sharing a short post about sharing code and how it can help the one who's sharing the code. I'll be giving a real life example of how it happened to me. My story Back when I was implementing first version of my simple-todo REST-service I used Scala and Play framework for the service and specs2 for testing the implementation. Since then I've done a few other implementations of the service but I've continued to use specs2 as a testing framework. I wrote about my implementation and shared the post through various services and as a result someone forked my work and gave me some pointers on how I could improve my tests. That someone was Eric Torreborre  the man behind specs2 framework. I didn't take his ref

Simple code: Immutability

Immutability is a special thing that in my mind deserves a short explanation and praise. If you're familiar with functional programming you surely recognice the concept of immutability because it's a key ingredient of the paradigm. In the world of object oriented programming it's not as used and as easy to use approach but there are ways to incorporate immutability to parts of the code and I strongly suggest you to do so. Quick intro to immutablity The basic idea of immutability is unchangeable data.  Lets take a example. We have a need to modify a object's property but because the object is immutable we can't just change value but instead we make a copy of the object and while making the copy we provide the new value for the copy. In code it looks something like this. val pencil = Product(name = "Pencil", category = "Office supply") val blackMarker = pencil.copy(name = "Black marker") The same idea can be applied in functions and metho

Simple code: Naming things

There are two hard things in programming and naming is one them. If you don't believe me ask Martin Fowler https://www.martinfowler.com/bliki/TwoHardThings.html . In this post I'll be covering some general conventions for naming things to improve readability and understandabilty of the code. There are lots of things that need a name in programming. Starting from higher abstractions to lower we need to name a project, API or library, we probably need to name the source code repository, when we get to the code we need to name our modules or packages, we give names to classes, objects, interfaces and in those we name our functions or methods and within those we name our variables. Overall a lot of things to name. TLDR; Basic rule There's a single basic convention to follow to achiveve better, more descriptive naming of things. Give it a meaningful name i.e. don't use shorthands like gen or single letter variables like a, x, z instead tell what it represents, what it does