A Stack Change

In the not so distant past I was assigned to a very interesting HTML5 / JavaScript project. I used to say that I’m familiar with JS and I even add it to my resume with a modest years of experience number. Needles to say that as soon as I had to dive deeper into the JS world my confidence vanished away.

On the other hand I learned tons of new stuff. I can only compare the current knowledge gaining to the very beginning of my career, when I started to learn C# and ASP.NET.

The reason I write this post is twofold. First, I want to propagate the idea of abandoning your well-known technology stack for a while to learn something entirely different. I believe there’s succinct and fundamental diversities between the C# and the JS world. It successfully moved me out from being stuck in a warm and fuzzy world with little uncertainty. It also opened lots of new opportunities.

The other reason is that I plan to write some follow up posts on the more intricate stuff that was quite a pain to figure out in the current cutting edge JS stack. To name a few, I got the chance to work with AngularJS, RequireJS, Node, NPM, Bower, Grunt, Karma, Jasmine, etc. I also had the opportunity to get into a more intimate relationship with functional programming practices and JS per se.

Brace yourselves, complete stack change is coming.


How I failed to pivot because of the ‘coolness factor’

iBeacons? Build something with them!

A couple of months ago I was browsing the news and stumbled upon Apple’s iBeacon technology. After some digging on the internet I figured I would like to build something awesome on it. I started brainstorming with my best friend and all-time business partner on the potential and what we could do. Initially I had a hard time trying to persuade him thinking out of the box. Apple has set some boundaries for this technology in the way they pivot it. They proposed indoor navigation or showing some price tags. However in two or three quick iterations we had the idea ready: use it as a foundation of a new dating app. Ironically we failed because I was unable to think out of the box – and didn’t see the need to the pivot.

The idea – let’s revolutionise dating!

The app’s workflow was pretty simple: you fill a form about yourself and your dating preferences. The app immediately starts to publish this information on Bluetooth Low Energy. In the same time it starts a subscriber and polls for other people’s broadcast. If someone is within range and there’s a match you and the potential partner would receive a push notification, asking whether or not you like the other party. You’d be able to show interest in the other party by hitting a nice green “Interested” button. Alternatively you could politely turn them down by tapping on the red “Not interested” one. If both parties are interested they are notified and they can begin getting to know each other. Due to the very nature of BLE and iBeacons, these people would be in close proximity, so this would be pretty easy.

Why would anyone use this thing?

Now what is the purpose of this? Why would I fiddle with my smartphone instead of just walking up the other person? In one word, what is the pitch? Well, for starters the sad thing is that everybody is always hooked on their phone. I’m not in the position to judge this, but sometimes it’s pretty hard to deal with it. People are perceiving the world through their smartphone screens, and in the end, more aspects of “real” life would march to that screen. The other point is that everybody has insecurities. It takes courage to walk up to another person and initiate a conversation, particularly if you have romantic intentions. We’d just facilitate the meeting process by providing a painless (or at least, less painful) way to deal with rejection.

The technical problems

I implied in the beginning that we eventually failed to build this app. What was the problem? In short I was too focused to build something on iBeacons and BLE that I built the whole idea around it. And Apple has some technical limitations in place which made it impossible to deliver the product using this technology. In a few words, your app would have to run in the foreground, and the other party’s app too. This of course is not a viable scenario for this kind of app.

And failing to overcome them

I was so blinded by the cool new technology factor that when it turned out we cannot do this I didn’t start to pivot, despite all the startup literature I read. And we were pretty close, with just a little pivoting, we could have delivered a working product. The proof is ntice, a Hungarian startup with the exact same idea.


So what’s the conclusion? It’s pretty clear from the outside and common sense dictates that you need to pivot or persevere (or, worst case, let it go). This scenario was clearly a pivot one, the solution would be to ditch iBeacon and work on some check-in based stuff like Foursquare. Or ditch Apple and go with Android. Or something else that never occurred to me. But never ever let the opportunity of using a cool technology cloud your judgement.

Wordnik API for Windows 8 and Windows Phone 8

I was thinking about creating some app dealing with words for WP8. One big hurdle was getting definitions for user-entered words, so I started searching for online services with APIs for the purpose.

The first obvious choice was Google Dictionary, but the API is not public (and unsupported), despite all the requests from the dev community. I saw a link there for Wordnik, a word and phrase dictionary with a nice API. The only problem was that they didn’t have a C# API which could be used with Windows 8 or Windows Phone 8. The nearest thing to C# was their Java API client, so I grabbed that and rewrote the stuff for using the portable HttpClient. This means that you can use the API client with Windows 8 and Windows Phone 8 as well. The result is this project on GitHub, a portable library for the Wordnik API.

The API client can exercise the whole Wordnik API, all you need is to get an API key from Wordnik (a fairly easy process), and put it in the Api/ApiKey.cs file.

I hope it would prove useful for someone else as well.

Git Viewer, my first WP8 app is published

In my previous post I wrote about a Windows Phone 8 app I built. Now it’s available in the app store.

As a recap, this app lets you connect to your GitHub repositories and check various aspects of them. If you’re interested, you can also check out the source code on GitHub. I’m not done with the development, currently there’re some new features ready, but I haven’t done testing and updating the app. I welcome any participation to provide some nice GitHub experience on Windows Phone 8 as well.

I made an app for Windows Phone 8

It’s winter and I’m on a holiday so I have lots of free time at my hands. I thought that maybe I could spend it in a productive fashion, so I wrote an app for Windows Phone 8.

The app itself is a GitHub client, which lets you check out your repositories, view files and diffs and do other stuff. It’s open source, of course, and hosted on GitHub. Check out the source code!

Connecting to the API

I knew it won’t be a walk in the park, but there’s a very nice project on GitHub which lets you use the whole API, called OctoKit.NET.  It even has a portable library for Windows Store. But not for Windows Phone, so you have to take portable as in portable to another Windows 8 PC. Something is seriously messed up here, and we’re heading towards a new kind of DLL hell.

But it’s not the fault of the guys behind OctoKit, this is the current ecosystem. I thought that I’d fork their project and do some changes to make it a portable library for Windows Phone 8. Nope, that’s not going to happen. Networking code is not part of the portable stuff, you have to do that in your Windows Phone project.

So I did that there. Wrote a client for the API parts I actually needed, and used that. It wasn’t a huge work, and JSON.NET made it very easy as well.


There’s decent MVVM support in the WP8 controls, but I ran into some horrible stuff which seriously messes up properly architectured code. One being the ApplicationBar control, which doesn’t support bindings. Even the sample project has that horrible commented out stub like BuildLocalizedAppBar. Also it doesn’t support commands, so you’ve to have event handlers in your XAML code behind, instead using the ViewModel for this stuff. That’s a shame. I hope that Microsoft fleshes this out in some upcoming release.

Some limitations

I wanted to build a page for viewing your source code files and diffs. I’m a fan of short files with one class in them, but there’s a perfectly fine chance that files grow bigger. The idea was to grab a TextBlock and bind it to the file text. Later when I feel like syntax highlighting, I’d ditch the TextBlock and try something else.

However I noticed that a TextBlock (or any other control, by the way) tends to cut off its content after some height. It turned out that the maximal control height in WP8 is about 2040 pixels. So I wrote an abomination to split the stuff into small chunks and add it dynamically to a StackPanel. Ugly and broke MVVM brutally. I know about a control written for WP7 that doesn’t cut off stuff, but there were some changes between the versions, and it wasn’t worth the effort to adapt it for a fun project like this.

Lack of unit testing support

Now this almost made me gave up the project. I wondered what can be the Windows Phone 8 Unit Tests template in Visual Studio, but I never thought that they want me to run my tests on my actual phone (or buy Windows 8 Pro and use an emulator). Am I supposed to connect a phone to a build server and run the tests there if I’m serious about WP8 development?

The excuse was laughable at best: WP8 code relies so much on WP8 libraries that the unit tests will surely touch libraries depending on the platform. I did a fairly big amount of SharePoint unit testing, which enforces that too, but never needed to run my tests in a SharePoint server. The whole point of unit tests would be to test a unit of code, and if you really need it, provide some mocks or stubs for the dependencies. I think that Microsoft got this one really bad.

So what’s the point?

Windows Phone 8 as a development platform doesn’t seem that mature for me. There are lots of quirks and you have to do lots of workarounds for simple stuff. A template project requiring workarounds is something I haven’t seen yet anywhere else.

The development tools on the other hand are fairly robust, it’s a pleasure to write mobile apps with Visual Studio at last. However Microsoft doesn’t seem to be in a position to ship incomplete libraries for developers, as this clearly won’t help overcome their chicken and egg problem of nobody develops on the platform because there are not enough users because nobody develops apps.

I think I’d consider iOS as my primary mobile development platform, and write some fun side projects if I have the time and resources for WP8.

Book Read: Pro .NET Performance

I’ve read this title several weeks ago and thinking of writing a blog post about it ever since I’ve finished it. Originally I was interested in learning something new about performance issues and resolutions in .NET, but the book managed to deliver some rather interesting and valuable content besides that. I’d say that the strongest and most useful material wasn’t about performance but CLR internals.

There were tons of information about CLR data structures and how classes and structs lied out in memory. That chapter alone worth well the price of the book. Also there was great coverage on garbage collection flavors and the concrete .NET GC implementation was explained well.

Of course performance was considered as well with some useful advice (on how to attack performance problems and how and what to measure at all), but the CLR internal parts were written and explained in a great manner, covering the latest version of .NET.

Until I find the time to read the most recent CLR via C# this book was a great refresher on the subject.

Mobile event viewer: User Interface

This is the second post of a series of tutorials for creating an event viewer for iOS. You can find the first post, which deals with basic architecture an network connections, here.

There’s also an accompanying Github project.

This post will be about the user interface. Since no built-in control exist for mimicking the calendar day view in iOS (neither in Android) and I’m not very great drawing controls, I started checking for open source implementations. There’s a very easy to use project on Github by muhku, called calendar-ui.

What we need from it is the MADayView class, along with MAEvent. MADayView, as the name suggests provides a view which renders the calendar day view. It has a delegate and a datasource property. In my example, I rigged both, but only used the datasource. Here’s how I set up the view.

EventListViewController.h changed a little:

As you can see, I imported MADayView.h, and added its datasource and delegate protocols to the header. I also added an IBOutlet for MADayView, and connected it to its counterpart in EventListViewController.xib. Basically the UITableView implementation was replaced to an MADayView implementation. In EventListViewController.m there are some changes too:

The main change here is that instead of UITableView I use MADayView. Its datasource protocol is very easy to satisfy, only a method with the signature: (NSArray*)dayView:(MADayView*)dayView eventsForDate:(NSDate*)startDate needs to be implemented.

This method unfortunately needs to return an array of MAEvent objects. I like to separate third party code from my, so I created a mapper which maps my own Event class to an MAEvent (a variant of the Adapter pattern). This way, if the very unlikely day would come when I want to change the UI in this tutorial, I could do with minimal changes. There are also two callback methods from MADayView which I put in there for paging: nextDate and previousDate. These should be the part of the delegate protocol, but I was sloppy and just use two selectors for the effect.

What may be interesting in these methods are the [actualDate yesterday] and [actualDate tomorrow] calls. These are implemented in a category on NSDate. The code looks like the following:

It simply uses NSDateComponents to increment or decrement the date on which it’s called (thus working with daylight saving times, leap years, etc.).

In the following post, I’ll show how to scroll between days to implement a truly native experience.